(FIGS 8–10)
Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: 02A15862-0D93-40B4-BD9A-0F41E6D70CA6.
Type fixation: Holotype, preparatory female, ZMH K-55342, 3.6 mm, designated here.
Material examined: Holotype: female (preparatory, Na 23), 3.6 mm, CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 24 (start: 11°51’19’’N, 117°1’30’’W, 4093 m; end: 11°51’31’’N, 116°58’0’’W, 4093 m), date: 22/03/2015, ZMH K-55342.
Paratypes: Preparatory female (Na 25), same location as holotype, ZMH K-55381; preparatory female (NB12 _Iso020), CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 06 (start: 11°46’13’’N, 116°41’8’’W, 4259 m; end: 11°46’13’’N, 116°41’7’’W, 4259 m), date: 02/04/2012, ZMH K-55341.
Etymology: The new species (noun in apposition) is named after Ana Hilario for her support and enthusiasm to join the SO239 ‘Berta’ team (in this case down to 4259 m).
Distribution: Only known from the type locality (German licence area, eastern CCZ), between 4093 and 4259 m depth.
Diagnosis: Body slender, length about 5.5 × pereonite 1 width; Mxp lateral margin with numerous small setae; Mxp epipodite reaching distal third of palpal article 2; molar process of both Md with ≥ nine distal spines each; Md incisor teeth rounded; pereonite 2 anterolateral tergites each with robust seta; pereonite 7 without ventral spine; Op with ventral posteriorly bent spine, posterior margin with several (≤ nine) long simple setae; Urp biramous, not projecting beyond Plt posterior margin; Urp exopodite minute, endopodite length ≥ 6.3 exopodite length.
Description of holotype and paratype female: Habitus (Figs 8A, E, 10), body length 5.5 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Figs 8A, E, 10D–E) almost as long as wide. Anterior and lateral margins straight, posterior margin slightly rounded. Antennae inserting frontolaterally in deep fold. Pereonites 1–4 of similar height, abruptly flattening from pereonite 4 to 5. Pereonites 1 and 2 of similar width, gradually decreasing in width from 2 to 7; pereonite 1 length 0.3 width. Pereonite 2 length 1.3 pereonite 1 length, length 0.4 width. Pereonite 3 length 1.8 pereonite 1 length; pereonite 4 length 1.7 pereonite 1 length. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of pereonite 2 each tipped with robust seta, anterolateral tergites of pereonites 3–4 each tipped with simple seta. Pereonite 5 longest, length 1.9 pereonite 1 length, anterior margin straight. Pereonites 6–7 dorsomedially fused; pereonite 6 anterior margin convex. Plt length 0.2 body length, length 1.2 width, width 0.9 pereonite 1 width; posterior margin strongly rounded; anterior margin slightly concave. Urp length 0.3 Plt length, not projecting beyond posterior margin. AI (Fig. 8B) length 0.1 body length, with five articles. First article length 2.3 width, with one small broom seta and one simple seta distally. Second article length 0.7 article 1 length, length 1.4 width, with two broom setae (broken off) and one simple seta distally. Article 3 minute, length 0.1 article 1 length, length 0.3 width. Article 4 length 0.2 article 1 length, with long distal projection reaching mid of article 5, with one small broom seta distally. Article 5 slightly damaged, length 0.7 article 1 length, length 2.5 width, with one aestetasc (?, broken off) terminally. AII (Fig. 8B) broken off, only podomere articles 1–4 present; articles quadrangular of similar length and width. Md (Fig. 8C, D), palp of left mandible well developed (in rMd broken off), consisting of three articles almost reaching incisor. LMd palpal article 2 length 1.5 article 1 length. Terminal article length 0.3 article 2 length, tapering distally, with two setae distally. Incisor process of rMd with four rounded teeth, incisor of lMd with two rounded teeth. Lacinia mobilis of lMd with three teeth. Spine row of rMd with nine robust spines increasing in size proximally. Spine row of lMd with eight robust spines and several slender setae in between, dentation decreasing, seta size increasing proximally. Molar of rMd and lMd triangular; molar of rMd with 10, of lMd with nine serrate spines distally. Mxp (Fig. 8F), left and right Mxp connected by two retinacula. Epipodite smooth, triangular, slender, length 4 width, reaching distal third of palpal article 2. Palpal article 1 short, width 0.3 length, with several small setae laterally. Article 2 length 3 article 1 length, width 1.1 length, with several small setae laterally, with one simple seta distally. Article 3 length 3 article 1 length, width 0.9 length, with two robust sensory setae distally with one simple seta laterally. Article 4 length 1.1 article 1 length, width 0.5 length. Article 5 length 0.6 article 1 length, width 0.5 length, with five slender setae of varying size terminally. Endite distal margin with some robust setae and several fine setae laterally. Basis triangular, length 0.9 width. PI (Fig. 9C) basis length 2.7 width. Ischium 0.6 basis length, length about twice width. Merus length 0.7 ischium length, length 1.5 width, with two long simple setae distodorsally, with one small simple seta distoventrally. Carpus length 1.7 merus length, length 2.5 width, with three unequally bifid setae, increasing in size distally, and one simple seta ventrally. Propodus length 0.7 carpus length, length 2.3 width, with numerous small setae, membranously embedded ventrally, and one robust unequally bifid seta and one simple seta distoventrally. Dactylus length about half propodus length, length 2.9 width. Unguis length 0.9 dactylus length, with two long, slender setae underneath unguis. PII (Fig. 9D) basis length 3.5 width, with one seta (broken off) ventrally. Ischium length about half basis length, length twice width, one long simple seta distodorsally. Merus length 0.9 ischium length, length 1.6 width, with one robust simple seta distodorsally, with one slender simple seta distoventrally. Carpus length 1.9 merus length, length 3.6 width, with one simple seta distodorsally, with row of four unequally bifid setae ventrally, increasing in size distally. Propodus length 0.7 carpus length, length 4 width, with one long simple seta distodorsally, with numerous small setae, membranously embedded ventrally, with one small unequally bifid seta distoventrally. Dactylus length 0.4 propodus length, length 3 width, with numerous small setae, membranously embedded ventrally. Unguis length about half dactylus length, with one slender seta between unguis and ventral claw. PIV (Fig. 9E) slightly damaged between ischium and merus. Basis length 4.8 width, with one short simple seta and one long broom seta dorsally. Ischium length half basis length, length 2.5 width, with two small simple setae dorsally. Merus length 0.6 ischium length, length 1.9 width, with one simple seta distodorsally, with two simple setae (one long, one broken off) distoventrally. Carpus length 2.2 merus length, length 4.7, with one unequally bifid setae (one broken off) ventrally. Propodus length 0.7 carpus length, length 4.8 width, with three long simple setae dorsally, with one slender simple and one stout unequally bifid setae ventrally. Dactylus length 0.3 propodus length, length 2.3 width. Unguis length 1.1 dactylus length, with two slender setae underneath unguis. PV (Fig. 9F) slightly damaged between basis and ischium. Basis length 3.3 width, with one simple seta dorsally, with two simple setae ventrally, with one long simple seta distoventrally. Ischium length 0.9 basis length, length 3 width, with one simple seta dorsally. Merus length 0.4 ischium length, length 1.6 width, with one long simple seta distodorsally, with one long simple seta ventrally, with one seta (broken off) distoventrally. Carpus length 2.3 merus length, length 3.5 width, with four long slender setae ventrally. Propodus length 0.7 carpus length, length 4 width, with five long simple setae dorsally. Dactylus length 0.4 propodus length, length 3.2 width. Unguis length 0.8 dactylus length, with two slender setae underneath unguis. Op (Fig. 8G) length 1.3 width, with strong ventral spine, posteriorly bent. Lateral margin and posterior margins rounded, with several (≤ nine) simple setae, setal length 0.2 Plt length. PlpIII (Fig. 8H), protopodite almost as long as wide, length about half endopodite length. Exopodite half endopodite length, length 2.3 width, tapering in width distally, with numerous short simple setae laterally and one somewhat longer seta distally. Endopodite length 1.6 width, with three long plumose setae distally, distal margin rounded. Urp (Fig. 8J) biramous, length 0.25 Plt length, not projecting beyond Plt posterior margin. Protopodite trapezoid, length 1.3 width, with one long simple seta laterally. Exopodite length 0.3 protopodite length, length twice width, with two simple setae terminally. Endopodite length 6.3 exopodite length, length 3.8 width, with two long simple setae and two long broom setae terminally.
Remarks: Nannoniscus hilario is most similar to species with a slender body (length ≥ 4.5 pereonite 1 width), biramous uropods and a ventral opercular spine, viz.: N. menziesi, N. meteori and N. perunis.
The new species can be distinguished from N. menziesi by the following characters: Mxp lateral margin with numerous small simple setae (vs. setae lacking in N. menziesi); Op posterior margin with ≤ nine simple setae (vs. 18 setae); incisor teeth of left and right Md more rounded (vs. acute). Nannoniscus hilario also resembles N. meteori, but can be differentiated as follows: Mxp lateral margin with numerous small simple setae (vs. setae lacking in N. meteori); Mxp endopodite reaching distal third of palpal article 2 (vs. mid of palpal article 3); Op posterior margin with ≤ nine simple setae (vs. 15 setae); Urp endopodite length 6.3 exopodite length (vs. 3.9). The new species can be furthermore differentiated from N. perunis by the following features: body length ≥ 5.5 pereonite 1 width (vs. ≤ 4.7 in N. perunis); Urp endopodite length 6.3 exopodite length (vs. 7.8); pereonites 3–4 tergites each with an anterolateral seta (vs. setae lacking).
NANNONISCUS MAGDAE KAISER, BRIX & JENNINGS,(FIGS 11–14)
Zoobank registration: urn:lsid:zoobank.org:act: B36BAA31-FE02-4E33-BB83-CA8444FB91E5.
Type fixation: Holotype, preparatory female, ZMH K-55375, 2.2 mm, designated here.
Material examined: Holotype: preparatory female (Na26), 2.2 mm, CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 171 (start: 14°2’41’’N, 130°5’57’’W, 5024 m; end: 14°3’12’’N, 130°4’36’’W, 5017 m), date: 17/04/2015, ZMH K-55375.
Paratypes: Preparatory female (Na12), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, same station as holotype, ZMH K-55374; preparatory female (NB12Iso99), CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 67 (start: 14°3’4’’N, 130°4’36’’W, 5021 m; end: 14°3’10’’N, 130°4’27’’W, 5021 m), date: 19/04/2012, ZMH K-55373; ovigerous female (Na28), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, same station as holotype, ZMH K-55376; juvenile male (Na49), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, same station as holotype, ZMH K-55377.
Etymology: The new species (magdae, Latin genitive, feminine) is named in honour of Magdalena Błażewicz for her invaluable help onboard the SO239 Ecoresponse voyage, and her contributions to the taxonomy and biodiversity of deep-sea peracarids.
Distribution: Based on the material available (four specimens), this species has a restricted distribution and is only known from the French licence area of the CCZ, between 5017 and 5024 m depth.
Diagnosis: Body slender, length about 4.8 × pereonite 1 width; Mxp lateral margin with numerous small setae; Mxp epipodite reaching mid of palpal article 3; molar process of both Md with ≥ nine distal spines each; Md incisor teeth rounded; pereonite 2 anterolateral tergites devoid of setae; pereonite 7 without ventral spine; Op with ventral posteriorly bent spine, posterior margin with numerous (≥ 17) long simple setae; Urp biramous, not projecting beyond Plt posterior margin; Urp endopodite length about 2.1 exopodite length.
Description of holotype and paratype female: Habitus (Figs 11B, D, 14A–C), body length 4.8 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Figs 11B, 14D–E) as long as wide (measured from lateral view). Anterior margin straight, posterior and lateral margins slightly rounded. Antennae inserting frontolaterally in deep fold. Pereonites 1–4 gradually flattening, then abruptly flattening from pereonite 4 to 5. Pereonites 1–3 of similar width, gradually decreasing in width from 3 to 7; pereonite 1 length 0.4 width. Pereonite 2 width 0.5 pereonite 1 width, length 1.2 pereonite 1 length. Pereonites 2 and 3 of similar length; pereonite 4 length 1.1 pereonite 1 length. Pereonites 1–4 anterior margins frontally directed, without setation. Pereonite 5 length 1.1 pereonite 1 length, anterior margin straight. Pereonites 6–7 dorsomedially fused, pereonite anterior margin slightly convex. Plt length 0.2 body length, length 1.5 width; width 0.7 pereonite 1 width, posterior margin strongly rounded; anterior margin straight. Urp length 0.3 Plt length, not projecting beyond posterior margin. AI (Fig. 11A) length 0.1 body length, with five articles. First article circular and broadest, with one small broom seta distally. Second article length twice width, with three broom setae (one broken off) and one small simple seta distally. Article 3 minute, length 0.2 article 2 length, as long as wide. Article 4 length 0.3 article 2 length, with long distal projection reaching mid of article 5, with two simple setae of varying size distally. Article 5 length 0.9 article 2 length, length 1.6 width, with one aestetasc terminally. AII (Fig. 11C) length 0.4 body length, with six podomere and seven flagellar articles. Podomere articles 1–4 short; article 1 with one simple seta distally; article 3 with two simple setae distally, article 4 with one simple seta distally. Article 5 longest, length 1.3 articles 1–4 length, length approximately 4.1 width, with two simple setae laterally. Article 6 length 0.8 article 5 length, length 3.3 width, with two broom setae of varying size and one long simple seta distally. Flagellar article 1 longest, conjoint with two setal positions (fusion of three articles), length 0.9 podomere article 6 length, length 4.6 width, with two simple setae laterally. Flagellar articles 2–7 decreasing in length and width distally; each article with 1–3 short simple setae distally. Article 7 with 5 long slender setae terminally. Md (Fig. 11E, F), palp of left and right mandible well developed, consisting of three articles reaching mid of incisor. Palpal article 2 of rMd length 1.7 article 1 length, with two simple setae laterally. Terminal article length 0.4 article 2 length, tapering distally, with several (≥ nine) small setae ventrally and three somewhat longer setae terminally. Incisor process of rMd with three rounded teeth, incisor of lMd with rounded three teeth. Lacinia mobilis of lMd with three teeth. Spine row of rMd with 10 robust spines and several slender setae in between; dentation decreasing and setal size increasing proximally. Spine row of lMd with ten robust spines and several slender setae in between, dentation decreasing, seta length increasing proximally. Molar of rMd and lMd triangular; molar of rMd and lMd each with nine long, serrate spines distally. Mxp (Fig. 11G), left and right Mxp connected by three retinacula. Epipodite smooth, triangular, slender, length 3.1 width, reaching mid of palpal article 3. Palpal article 1 short, width 1.6 length, with several small setae lateral. Article 2 length 1.9 article 1 length, as long as wide, with several small setae laterally. Article 3 length 1.6 article 1 length, width 0.9 length, with four robust sensory setae distally and two simple setae laterally. Article 4 as long as article 1, width 0.5 length, with distal projection reaching mid of article 5, with three slender setae distally. Article 5 length 0.6 article 1 length, width 0.4 length, with three slender setae terminally. Endite distal margin with some robust, dentate setae and several fine setae laterally. Basis triangular, length 0.7 width. PI (Fig. 12C) basis length 2.7 width. Ischium length about half basis length, length 2.2 width, with two simple setae distodorsally, with one simple seta ventrally. Merus length 0.7 ischium length, length 1.4 width, with two simple seta distodorsally, with one long simple setae distoventrally. Carpus length 1.6 merus length, length 2.4 width, with one simple seta distodorsally, with row of six simple setae ventrally. Propodus length 0.9 carpus length, length 3.8 width, with one simple seta dorsally, with numerous small setae, membranously embedded, and two small unequally bifid setae in between ventrally. Dactylus length about half propodus length, length 4.5 width, with one small simple setae medially. Unguis length half dactylus length, with two long, slender setae underneath unguis. PII (Fig. 12D) basis length 3.7 width, with one simple seta distoventrally. Ischium length about half basis length, length twice width, with five simple setae dorsally, with one simple seta distodorsally. Merus length 0.8 ischium length, length 1.5 width, with one simple seta (broken off) distodorsally, with one simple seta distoventrally. Carpus length 2.3 merus length, length 3.9 width, with six long slender simple setae and two long robust setae ventrally. Propodus length 0.6 carpus length, length 3.7 width, with two simple setae dorsally, with numerous small setae, membranously embedded, and three simple setae in between ventrally. Dactylus length 2.4 propodus length, length 3 width, with two simple setae medially, with numerous small setae ventrally. Unguis length 0.7 dactylus length, with two slender setae underneath unguis. PIII (Fig. 12E) damaged between basis and ischium. Basis length 4.4 width. Ischium length about half basis length, length 2.3 width, with one simple seta distodorsally, with one simple seta ventrally. Merus length 0.8 ischium length, length 1.8 width, with one small seta distodorsally, with one somewhat longer seta distoventrally. Carpus length 2.3 merus length, length 4.5 width, with 11 long slender setae (four broken off) ventrally. Propodus length 0.7 carpus length, length 4.3 width, with three long simple setae dorsally. Dactylus length 0.3 propodus length, length 2.3 width. Unguis damaged, as long as dactylus. PIV (Fig. 12F) basis length 5.9 width, with one simple seta ventrally. Ischium length 0.6 basis length, length 3.8 width. Merus length 0.6 ischium length, length 2.2 width, with one small simple seta distodorsally, with one long simple seta distoventrally. Carpus length 2.2 merus length, length 4.7 width, with nine long slender simple setae ventrally. Propodus length 0.7 carpus length, length 5 width, with numerous small setae and four simple seta ventrally. Dactylus length 0.4 propodus length, length 3.5 width. Unguis length 0.6 dactylus length, ventral claw length 0.3 ungius length. PV (Fig. 12G) basis length 4.9 width. Ischium length 0.8 basis length, length 3.1 width, with two long simple setae dorsally. Merus length about half length, length 1.8 width, with three simple setae (two long, one somewhat shorter) distodorsally. Carpus length twice merus length, length 3.6 width, with four long slender simple setae dorsally, with six long slender simple setae ventrally. Propodus length 0.6 carpus length, length 3.2 width, with four long simple setae dorsally, with five long simple setae ventrally. Dactylus length half propodus length, length 3 width. Unguis length 0.8 dactylus length, ventral claw length 0.6 ungius length. PVI (Fig. 12H) basis length 5.1 width, with three long simple setae ventrally. Ischium length 0.7 basis length, length 3.4 width. Merus length half ischium length, length 1.6 width, with two long simple setae distodorsally. Carpus length 2.4 merus length, length 4.1 width, with four long slender simple setae (one broken off) ventrally. Propodus length 0.6 carpus length, length 3.5 width, with seven long simple setae dorsally, with two simple setae of varying size ventrally. Dactylus length half propodus length, length 2.2 width. Unguis length 0.6 dactylus length, with two slender setae of varying size underneath unguis. PVII (Fig. 12I) slightly damaged between ischium and merus. Basis length 3.2 width. Ischium length 0.8 basis length, length 2.9 width, with one simple seta distodorsally. Merus length 0.4 ischium length, length 1.3 width, with one seta (broken off) distodorsally. Carpus length 2.4 merus length, length 3.1 width, with five slender simple setae (four long, one somewhat shorter) ventrally. Propodus length 0.7 carpus length, length 3.8 width, with seven long simple setae dorsally. Dactylus length 0.4 propodus length, length 4.5 width, with three simple setae medially. Unguis length 0.9 dactylus length, with two slender setae underneath unguis. Op (Fig. 11H) length 1.2 width, with strong ventral spine, posteriorly bent. Lateral margin rounded, posterior margin almost straight, with several (≥ 17) simple setae, setal size 0.3 Plt length. PlpIII (Fig. 11I), protopodite length 0.7 proximal width, length 0.4 endopodite length. Exopodite 0.5 endopodite length, length 1.6 width, width tapering distally, with numerous short simple setae laterally and one somewhat longer distally. Endopodite 1.2 length 1.5 width, with three long plumose setae distally, distal margin strongly rounded. PlpIV (Fig. 11J), protopodite rectangular, as long as wide, length 0.4 endopodite length. Exopodite slender, length 0.7 endopodite length, length 5 width, with several thin setules laterally (outer margin) and one long robust plumose seta distally. Endopodite ovoid-shaped, length twice width. PlpV (Fig. 11K), small oval lobe, without setation. Length twice proximal width, width gradually tapering towards distal end. Urp (Fig. 11L) biramous, length 0.2 Plt length, not projecting beyond Plt posterior margin. Protopodite length 1.5 proximal width, with three long simple setae distally. Exopodite length 0.5 protopodite length, length 4.5 width, with two long simple setae terminally. Endopodite length 2.1 exopodite length, length 3.8 width, with two simple setae (broken off), two long simple setae and two long broom setae terminally.
Description of male paratype: Habitus (Fig. 13). Body length 5.3 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Fig. 13A) length equals width. Anterior, lateral and posterior margins rounded. Antennae inserting frontolaterally in deep fold. Pereonites 3–6 decreasing in width. Pereonite 1 length 0.3 width. Pereonites 1–2 of similar width; pereonite 2 length 1.6 pereonite 1 length. Pereonites 2–3 of similar length. Pereonite 3 width 0.9 pereonite 1 width. Pereonites 2–5 of similar length. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of perenonite 1–4 each tipped with simple seta. Pereonites 4–7 of similar width, width 0.8 pereonite 1 width. Pereonite 5 anterior margin straight. Pereonites 6–7 dorsomedially fused, pereonite 6 anterior margin straight. Plt 0.2 body length, length 1.2 width, width 0.8 pereonite 1 width; posterior margin strongly rounded, anterior margin slightly concave. Urp not projecting beyond posterior margin. PlpI (Fig. 13B), length 2.5 proximal width. Distal projection width 0.5 proximal width, lateral margins straight. Lateral lobes rounded. Distal margins almost straight, with three simple setae. PlpII (Fig. 13C), sympod length 2.2 width, outer margin rounded, with one simple seta distally; inner margin straight. Endopod inserting 0.3 from distal tip of sympod. Stylet length 0.7 sympod length, slightly curved, distal end not extending beyond distal tip of sympod. Exopod short and rounded, inserting 0.1 from distal tip of sympod.
Remarks: The new species most closely resembles N. hilario, N. menziesi and N. perunis, but differs from these species by lacking robust setae on the anterolateral tergites of pereonite 2 and a markedly longer uropodal exopodite (Urp endopodite/exopodite length ratio 2.1 vs. ≥ 5.6 in the remaining species). Nannoniscus magdae can be furthermore distinguished from N. hilario as follows: Mxp endopodite reaching mid of palpal article 3 (vs. distal third of palpal article 2 in N.hilario); Op posterior margin with ≥ 17 simple setae (vs. ≤ 9). Additional characters to distinguish the new species from N. menziesi are: Mxp lateral margin with numerous small setae (vs. Mxp lateral margin lacking setae in N. menziesi); Md incisor teeth rounded (vs. acute). Nannoniscus magdae is also similar to N. meteori, but can be differentiated as follows: Mxp lateral margin with numerous small setae (vs. Mxp lateral margin lacking setae in N. meteori). The description of the male characteristics of N. magdae is based on a juvenile specimen, which can differ considerably from the terminal males (Riehl et al., 2012). However, since the specimen is the only male found for the new species, we found it to be a valuable addition to the female description.
NANNONISCUS MENOTI KAISER, JANSSEN &(FIGS 15–19)
Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: 8BFC86F5-43FE-41AF-B49B-2793B2E7C3B8.
Type fixation: Holotype, ovigerous female, ZMH K-55354, 3.6 mm, designated here.
Material examined: Holotype: ovigerous female (Na27), 3.6 mm, CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 171 (start: 14°2’41’’N, 130°5’57’’W, 5024 m; end: 14°3’12’’N, 130°4’36’’W, 5017 m), date: 17/04/2015, ZMH K-55354.
Paratype: Preparatory female (Na18), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20 (start: 11°50’9’’N, 117°58’29’’W, 4093 m; end: 11°50’11’’N, 116°58’0’’W, 4093 m), date: 21/03/2015, ZMH K-55356; preparatory female (Na06), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 117 (start: 13°52’19’’N, 123°15’27’’W, 4498 m; end: 13°52’37’’N, 123°14’16’’W, 4521 m), date: 07/04/2015, ZMH K-55352; adult male (MA14_Iso272), CCZ, equatorial NE Pacific, KM14 expedition, RV Kilo Moana, EBS, station 38 (start: 11°47 52’’N, 117°30’31’’W, 4363 m; end: 11°48’3’’N, 117°29’45’’W, 4373 m), date: 13/05/2014, ZMH K-55350; preparatory female (Na42/Iso1120), APEI-6, equatorial NE Pacific, ABYSSLINE-2 expedition, RV Thomas G. Thompson, EBS, station APEI-6#1 (start: 19°27’52’’N, 120°1’31’’W, 4099 m; end: 120°0’58’’N, 120°0’58’’W, 4076 m), date: 20/03/2015, ZMH K-55355; preparatory female (NB12_Iso068), CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 33 (start: 11°51’44’’N, 117°3’10’’W, 4133 m; end: 11°51’54’’N, 117°3’8’’W, 4133 m), date: 07/04/2012, ZMH K-55353; preparatory female (MA14_Iso352), CCZ, equatorial NE Pacific, MA14 expedition, RV Kilo Moana, EBS, station 39 (start: 11°49’37’’N, 117°30’49’’W, 4361 m; end: 11°49’47’’N, 117°30’5’’W, 4343 m), date: 13/05/2014, ZMH K-55351; preparatory female (Na40/Iso1005), CCZ, equatorial NE Pacific, ABYSSLINE-2 expedition, RV Thomas G. Thompson, EBS, station S11 (start: 12°2’43.08’’N, 117°25’26’’W, 4223 m; end: 12°3’1.44’’N, 117°24’17’’W, 4235 m), date: 16/03/2015, ZMH K-55349; ovigerous female (MA13_ Iso453), CCZ, equatorial NE Pacific, MA13 expedition, RV Kilo Moana, EBS, station 90 (start: 11°49.718’N, 117°30.278’W, 4340 m; end: 11°49.906’N, 117°29.395’W, 4357 m), date: 03/05/2013, ZMH K-55348.
Etymology: The new species (menoti, Latin genitive, masculine) is named after Lenaick Menot, leader of the French party of the BIONOD expedition, for joint actions sieving and sorting the mud.
Distribution: This species has a wide distribution across the CCZ, being obtained from the eastern German, OMS, GSR and French (type locality) licence areas, as well as APEI-6 between 4076 and 5024 m depth.
Diagnosis: Body slender, length about 5.1 × pereonite 1 width; Mxp lateral margin with numerous small setae; Mxp epipodite reaching mid of palpal article 3; molar process of left Md with ≥ ten distal spines; Md incisor teeth rounded; pereonite 2 anterolateral tergites each with robust seta; pereonite 2 anterolateral tergites each with robust seta; pereonite 7 without ventral spine; Op with a ventral posteriorly bent spine, posterior margin with numerous (≥ 15) short simple setae; Urp uniramous, not projecting beyond Plt posterior margin; male PlpI without hook-like projections distally.
Description of holotype and paratype female: Habitus (Figs 15D, 18), pereonites 2 and 3 damaged. Body length 5.1 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Figs 15D, 18D, E), length 0.9 width. Anterior and lateral margins straight, posterior m a r g i n s l i g h t l y r o u n d e d. A n t e n n a e i n s e r t i n g frontolaterally in a deep fold. Pereonite 2 widest, pereonites 2–7 decreasing in width. Pereonite 1 width 0.8 pereonite 2 width, length 0.4 width. Pereonites 2 and 3 of similar length and width, length approximately 1.3 pereonite 1 length. Pereonite 4 longest, length 1.7 pereonite 1 length. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of pereonite 2 each tipped with a robust seta, pereonites 3–4 each with a slender seta. Pereonite 5 width 0.9 pereonite 1 width, length 1.6 pereonite 1 length; pereonite 5 anterior margin slightly convex. Pereonites 6–7 dorsomedially fused, pereonite 6 anterior margin convex. Plt length 0.2 body length, length 1.4 width; width 0.9 pereonite 1 width, posterior margin strongly rounded; anterior margin straight. Urp length 0.2 Plt length, not projecting beyond posterior margin. AI described in situ from CLSM (Fig. 18A, E), from CLSM. Length 0.1 body length, with five articles. First article broadest, length twice width, with one broom seta distally. Second article as long as article 1, length 2.4 width, with two broom setae distally. Article 3 minute, length 0.2 article 1 length, as long as wide. Article 4 length 0.3 article 1 length, with a long distal projection reaching mid of article 5. Article 5 length 0.7 article 2 length, length 1.8 width. AII (Fig. 15A) length 0.4 body length, with six podomere and 11 flagellar articles. Podomere article 1 broken off, described from CLSM (Fig. 18A). Articles 1–4 short; article 3 with three simple setae and one small robust spine distally, article 4 with one simple seta distally. Article 5 length 1.5 articles 1–4 length, length approximately 5.8 width, with six simple setae laterally. Article 6 longest, length 1.1 article 5 length, length 6 width, with three simple setae laterally, with four broom setae of varying size and two long simple setae distally. Flagellar article 1 longest, conjoint with one setal position (fusion of 2 articles), length half podomere article 6 length, length 4.5 width, with two simple setae laterally. Flagellar articles 3–11 decreasing in length and width distally; each article with 1–3 simple setae distally. Article 11 with six long slender setae terminally. Md (Fig. 15B, C), palp of left and right Md broken off. Incisor process of rMd and lMd with four rounded teeth each. Lacinia mobilis of lMd with three teeth. Spine row of rMd with 12 robust spines, dentation decreasing proximally. Spine row of lMd with ten robust spines and several slender setae in between, dentation decreasing, seta size increasing proximally. Molar of lMd triangular, with ten serrate spines of varying size distally. MxII (Fig. 15E), outer margin of mesial endite with several setae of varying length, distal margin with numerous long setae of varying length. Mesial endite as long as lateral endite. Lateral endite and middle endite each with three strong setae distally. Mxp (Fig. 15F), left and right Mxp connected by three retinacula. Epipodite smooth, triangular, slender, length 3.1 width, reaching mid of palpal article 3. Palpal article 1 short, with several small setae laterally. Article 2 length 2.4 article 1 length, width 0.9 length, with several small setae laterally. Article 3 length 1.1 article 1 length, width 1.6 length, with four robust sensory setae (one broken off) and one somewhat longer simple seta distally. Article 4 length 1.4 article 1 length, width 0.3 length, with a distal projection reaching mid of article 5, with two slender setae distally. Article 5 length 0.8 article 1 length, width 0.3 length, with three slender setae of varying size terminally. Endite distal margin with some robust, dentate setae and several fine setae laterally. Basis quadrangular, length 0.9 width. PI (Fig. 16B) basis length 3.4 width, one small simple seta ventrally. Ischium 0.6 basis length, length 2.6 width, with one long simple seta distodorsally. Merus length 0.6 ischium length, length 1.4 width, with two long simple setae distodorsally. Carpus length 2.2 merus length, length 3.7 width, with one simple seta distodorsally, with five unequally bifid setae and numerous small setae ventrally. Propodus length 0.6 carpus length, length 3 width, with one simple seta dorsally, with numerous small setae, membranously embedded, ventrally, with one simple seta distoventrally. Dactylus length about half propodus length, length 3.7 width, with three slender setae medially. Unguis length half dactylus length, with two long, slender setae underneath unguis. PII (Fig. 16C) basis length 3.8 width. Ischium length about half basis length, length 2.3 width, with one long simple seta distodorsally. Merus length 0.7 ischium length, length 1.5 width, with two simple setae of varying length distodorsally, with one simple seta ventrally, and one simple seta distoventrally. Carpus length 2.6 merus length, length 4.3 width, with seven unequally bifid setae ventrally increasing in size distally. Propodus length 0.6 carpus length, length 4 width, with one long simple seta distodorsally, with numerous small setae, membranously embedded, and two small unequally bifid setae ventrally. Dactylus length 0.4 propodus length, length 3.3 width, with numerous small setae, membranously embedded ventrally. Unguis length half dactylus length, with two long, slender setae underneath unguis. PIII (Fig. 16D) basis length 4.7 width, with one long robust simple seta distoventrally. Ischium 0.4 basis length, length 2.1 width, with one simple seta distodorsally. Merus length 0.9 ischium length, length 1.8 width, with one simple seta distodorsally, with one simple seta (broken off) distoventrally. Carpus length 2.5 merus length, length 5.4 width, with eight robust setae (three unequally bifid setae, five simple) ventrally. Propodus length 0.6 carpus length, length 4.8 width, with six long simple setae (four broken off) dorsally, with numerous small setae, membranously embedded, and two small unequally bifid setae ventrally. Dactylus length 0.4 propodus length, length 6 width, with two simple setae medially. Unguis length 0.6 dactylus length, with two long, slender setae underneath unguis. PIV (Fig. 16E) basis length 5.5 width, with three simple setae dorsally, with three simple setae ventrally. Ischium length half basis length, length 2.9 width, with one simple seta distodorsally, with one simple seta ventrally. Merus length 0.6 ischium length, length twice width, with one long simple seta distodorsally, with one long simple seta distoventrally. Carpus length 2.5 merus length, length 6.4 width, with five simple setae (underneath) dorsally, with nine slender simple setae ventrally, increasing in size distally. Propodus length 0.6 carpus length, length 4.8 width, with six simple setae (four broken off) dorsally, with numerous small setae, membranously embedded, and four small unequally bifid setae ventrally. Dactylus length 0.4 propodus length, length 6 width, with two simple setae medially, with numerous small setae ventrally. Unguis length 0.3 dactylus length, with two slender setae underneath unguis. PV (Fig. 16F) basis length 4.5 width, one long simple seta distodorsally. Ischium length 0.8 basis length, length 3.6 width, with two long simple setae dorsally. Merus length half ischium length, length 1.8 width, with two simple setae of varying size distodorsally, with one small simple seta distoventrally. Carpus length 2.1 merus length, length 3.4 width, with six long simple setae (one broken off) ventrally. Propodus length 0.7 carpus length, length 2.9 width, with seven long simple setae (underneath) dorsally, with four long simple setae ventrally. Dactylus length half propodus length, length 3.5 width. Unguis length 0.7 dactylus length, with two setae of varying size underneath unguis. PVI (Fig. 16G) basis length 3.1 width, with one simple seta distoventrally. Ischium as long as basis, length 2.7 width, with one small simple seta ventrally. Merus length 0.4 ischium length, length 1.5 width, with two simple setae (one broken off) distodorsally, with one small simple seta ventrally. Carpus length 2.4 merus length, length 3.8 width, with one slender setae distodorsally, with three long simple setae ventrally. Propodus length 0.8 carpus length, length 5 width, with eight long setae dorsally, with two long setae distoventrally. Dactylus length half propodus length, length 5.3 width. Unguis length 0.8 dactylus length, with two slender seta underneath unguis. PVII (Fig. 16H) basis length 4.5 width. Ischium damaged, length 0.6 basis length, length 2.4 width. Merus length half ischium length, length 1.3 width. Carpus length 2.4 merus length, length 3.9 width, with eight long slender simple setae dorsally, with three simple setae dorsally, with one simple seta distodorsally, with three setae (two simple, one unequally bifid) of varying size ventrally. Propodus length 0.7 carpus length, length 4 width, with five long simple setae dorsally, with one simple seta ventrally, with one robust simple seta distoventrally. Dactylus length half propodus length, length 3.1 width. Unguis length 0.8 dactylus length, with two slender setae underneath unguis. Op (Fig. 15G), drawn in situ. Length 1.4 width, with a strong ventral spine, posteriorly bent. Lateral and posterior margins, with several (≥ 15) simple setae, setal size 0.1 Plt length. PlpIII (Fig. 15H) protopodite length 0.9 width, length 0.3 endopodite length. Exopodite half endopodite length, length 1.8 width, tapering in width distally, with numerous short simple setae laterally and one somewhat longer seta distally. Endopodite length 1.8 width, with two long plumose setae distally, distal margin rounded. PlpIV (Fig. 15I) protopodite rectangular, length 0.6 width, length 0.2 endopodite length. Exopodite slender, length 0.7 endopodite length, length 7.2 width, with several thin setules laterally (outer margin) and one long robust plumose seta distally. Endopodite length 2.6 width, distal end tapering in an acute angle. PlpV (Fig. 15J) small oval lobe, without setation, about as long as pleopod 4 endopodite. Length 2.2 proximal width, width tapering towards distal end. Urp (Fig. 15K) uniramous, length 0.2 Plt length, not projecting beyond Plt posterior margin. Protopodite oval, length 1.4 width, with five simple setae of varying length laterally. Endopodite length 1.6 protopodite length, length 5.3 width, with one broom seta laterally, with three broom setae and four simple setae (three broken off) terminally.
Description of male paratype: Habitus (Figs 17A, 19). Body length 5.7 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Figs 17A, 19D, E), length 1.1 width. Anterior and lateral margins rounded, posterior margin almost straight. Antennae inserting frontolaterally in a deep fold. Pereonites 2–5 decreasing in width. Pereonite 1 length 0.3 width. Pereonite 2 widest, width 1.1 pereonite 1 width, length 2.1 pereonite 1 length. Pereonites 2–3 of similar length. Pereonites 4–7 of similar length, pereonite 4 length 1.9 pereonite 1 length. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of perenonite 2 each tipped with a robust seta, anterolateral tergites of pereonites 3–4 each with simple seta. Pereonites 5–7 of similar width, width 0.8 pereonite 1 width. Pereonite 5 anterior margin straight. Pereonites 6–7 dorsomedially fused, pereonite 6 anterior margin straight. Plt 0.2 body length, length 1.4 width, width 0.7 pereonite 1 width; posterior margin strongly rounded, anterior margin slightly concave. Anus (Fig. 19B, F) covered by anus valves laterally. Urp inserting closely to the anus valves, length 0.2 Plt length, not projecting beyond posterior margin. PlpI (Figs 17B, 19B, F), length 3.2 proximal width. Distal projection width 0.4 proximal width, lateral margins slightly concave. Lateral lobes rounded, with five small setae inserting distally from each lateral lobe. Distal margins strongly rounded, with four simple setae of varying length each. PlpII (Fig. 17C), sympod length 2.5 width, outer margin rounded, with six long slender simple setae distally, with numerous small setae laterally; inner margin straight. Endopod inserting 0.3 from distal tip of sympod. Stylet length 0.6 sympod length, slightly curved, distal end not extending beyond distal tip of sympod. Exopod short and rounded, inserting 0.1 from distal tip of sympod. PlpIII (Fig. 17D), protopodite length 1.3 width, length half endopodite length. Exopodite half endopodite length, length 1.3 width, tapering in width distally, with numerous short simple setae laterally and one somewhat longer seta distally. Endopodite length 1.6 width, with three long plumose setae distally, distal margin rounded. PlpIV (Fig. 17E), protopodite rectangular, length 0.6 width, length 0.3 endopodite length. Exopodite slender, length 0.7 endopodite length, length 6.8 width, with several thin setules laterally (outer margin) and one long robust plumose seta distally. Endopodite length 1.8 width, distal margin rounded.
Remarks: The new species is distinct from most other species in the genus by possessing uniramous uropods. Besides N. menoti, only N. ovatus lacks a uropodal exopodite. The new species can be differentiated from N. ovatus as follows: body length 5.1 pereonite 1 width in female (vs. 4.7 in N. ovatus); Op posterior margin with ≥ 15 setae (vs. ≤ 9); Mxp lateral margin with numerous small setae (vs. Mxp lateral margin lacking setae); male PlpI without hook-like projections distally (vs. 3).
NANNONISCUS PEDRO KAISER, BRIX & KIHARA,(FIGS 20–22)
Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: 820608B2-7BAA-43B1-8B40-3A5561937B8B.
Type fixation: Holotype, preparatory female, ZMH K-55358, 3.4 mm, designated here.
Material examined: Holotype: preparatory female (Na08), 3.4 mm, CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 133 (start: 13°50‘45’’N, 123°15’39’’W, 4516 m; end: 13°51’8’’N, 123°14’8’’W, 4427 m), date: 10/04/2015, ZMH K-55358.
Paratypes: Ovigerous female (Na11), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 171 (start: 14°2’41’’N, 130°5’57’’W, 5024 m; end: 14°3’12’’N, 130°4’36’’W, 5017 m), date: 17/04/2015, ZMH K-55362; preparatory female (Na04), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20 (start: 11°50’9’’N, 117°58’29’’W, 4093 m; end: 11°50’11’’N, 116°58’0’’W, 4093 m), date: 21/03/2015, ZMH K-55361; preparatory female (Na05), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20, ZMH K-55365; preparatory female (Na22), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 24 (start: 11°51’19’’N, 117°1’30’’W, 4093 m; end: 11°51’31’’N, 116°58’0’’W, 4093 m), date: 22/03/2015, ZMH K-55363; preparatory female (NB12_Iso_290), CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 43 (start: 11°48’12’’N, 117°32’3’’W, 4358 m; end: 11°48’20’’N, 117°31’57’’W, 4358 m), date: 09/04/2012, ZMH K-55360; preparatory female (NB12_Iso_330), CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 43, ZMH K-55364; preparatory female (MA13_Iso593), CCZ, equatorial NE Pacific, MA13 expedition, RV Kilo Moana, EBS, station 90 (start: 11°49.718’N, 117°30.278’W, 4340 m; end: 11°49.906’N, 117°29.395’W, 4357 m), date: 03/05/2013, ZMH K-55359; preparatory female (MA13_ Iso049), CCZ, equatorial NE Pacific, MA13 expedition, RV Kilo Moana, EBS, station 07 (start: 11°51.503’N, 117°01.205’W, 4131 m; end: 11°51.756’N, 117°00.171’W, 4121 m), date: 12/04/2013, ZMH K-55357; female, badly damaged (MA14_Iso319), CCZ, equatorial NE Pacific, MA14 expedition, RV Kilo Moana, EBS, station 39 (start: 11°49’37’’N, 117°30’49’’W, 4361 m; end: 11°49’47’’N, 117°30’5’’W, 4343 m), date: 13/05/2014, ZMH K-55367; male, badly damaged (MA14_Iso242), CCZ, equatorial NE Pacific, MA14 expedition, RV Kilo Moana, EBS, station 39, date: 13/05/2014, ZMH K-55366.
Etymology: The name is a noun in apposition, and dedicated to Pedro Martinez Arbizu, Principal Investigator of the JPIO EcoResponse expedition, for his drive and commitment to the exploration of the abyssal manganese nodule fauna.
Distribution: The species has a broad distribution across the CCZ, being collected from the eastern German, GSR (type locality) and French licence areas between 4093 and 5024 m depth.
Diagnosis: Body slender, length about 5.5 × pereonite 1 width; Mxp epipodite reaching mid of palpal article 3; Mxp lateral margin lacking fringe of setae; molar process of both Md each with only a few (≤ 5) distal spines; Md incisor teeth acute; pereonite 2 anterolateral tergites each with robust seta; pereonite 7 without ventral spine; Op with a ventral posteriorly bent spine, posterior margin with numerous (≥ 21) long simple setae; Urp biramous, not projecting beyond Plt posterior margin; Urp endopodite length ≥ 3.2 exopodite length.
Description of holotype and paratype female: Habitus (Figs 20A, B, 22), body length 5.5 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Figs 20A, 22D–E), length 0.7 width. Anterior and posterior margins straight, lateral margin slightly rounded. Antennae inserting frontolaterally in a deep fold. Body abruptly flattening from pereonite 4 to 5. Pereonites 2–4 decreasing in width, pereonites 4–7 of similar width. Pereonite 1 length 0.3 width. Pereonite 1 and 2 of similar width, pereonite 2 length 1.7 pereonite 1 length. Pereonites 3 and 4 of similar length, length 1.2 pereonite 2. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of pereonite 2 each tipped with a robust seta, anterolateral tergites of pereonites 3 and 4 each with a simple seta. Pereonite 5 length 1.8 pereonite 1 length, anterior margin straight. Pereonites 6 and 7 dorsomedially fused, anterior margin of pereonite 6 convex. Plt length 0.2 body length, length 1.2 width, width 0.9 pereonite 1 width, posterior margin strongly rounded; anterior margin concave. Urp length 0.3 Plt length, not projecting beyond posterior margin. AI (Fig. 20C), terminal article broken off, inferred from CLSM (Fig. 22A, E). Length 0.1 body length, with five articles. First article circular and broadest, length 2.3 width. Second article length 0.7 article 1 length, length 1.8 width, with two simple setae distally. Article 3 minute, length 0.1 article 1 length, as long as wide. Article 4 length 0.1 article 2 length, with a long distal projection reaching mid of article 5, with one simple seta distally. Article 5 length 0.9 article 2 length, length 1.2 width, with one aestetasc terminally. AII (Fig. 20D) length 0.4 body length, with six podomere and nine flagellar articles. Podomere articles 1–4 short. Article 5 longest, length 1.2 articles 1–4 length, length 5.4 width. Article 6 length 0.9 article 5 length, length 5.6 width. Flagellar article 1 longest, conjoint (fusion of three articles), length 0.6 podomere article 6 length, length 4.8 width. Flagellar articles 2–4 of similar length, length 0.2 flagellar article 1 length. Flagellar 5 article longest, length 0.3 flagellar article 1 length. Flagellar articles 1–9 decreasing in width distally, each article with 0–3 simple setae distally. Article 9 with seven long slender setae terminally. Md (Fig. 21D, E), palp of right mandible damaged, of left mandible well developed, consisting of three articles almost reaching mid of incisor. Palpal article 2 of lMd length 1.2 article 1 length, with two simple setae laterally. Terminal article length about half article 2 length, tapering distally, with several small setae ventrally and two somewhat longer setae terminally. Incisor process of rMd with three acute teeth, incisor of lMd with six acute teeth and one subdistal tooth. Lacinia mobilis of lMd with three teeth. Spine row of rMd with ten robust spines of varying size and several slender setae in between; dentation decreasing proximally. Spine row of lMd with eight robust spines and several slender setae in between, dentation decreasing, spine size increasing proximally. Molar of rMd and lMd triangular; molar of rMd with four, of lMd with five long, serrate spines distally. MxI (Fig. 21F) outer endite with 17 robust spine-like setae distally. Outer margin with several slender setae. Inner endite width 0.6 outer endite width, several fine setae distally, with two simple setae laterally. MxII (Fig. 21G), outer margin of mesial endite with several setae of varying length, distal margin with numerous long setae of varying length. Mesial endite almost as long as lateral endite. Lateral endite and middle endite each with three strong setae distally. Mxp (Fig. 21C), left and right Mxp connected by three retinacula. Epipodite smooth, triangular, slender, length 3.1 width, reaching mid of palpal article 3. Palpal article 2 width 0.9 length. Article 3 length 0.7 article 2 length, width 1.2 length, with seven robust sensory setae distally. Article 4 length 0.4 article 2 length, width half length. Article 5 length 0.4 article 2 length, width 0.2 length, with two slender setae terminally. Endite distal margin with some robust, dentate setae and several fine setae laterally. Basis length 1.5 width. PI (Fig. 20E) basis length 4 width. Ischium about half basis length, length 2.3 width, with one long simple seta dorsally. Merus length 0.6 ischium length, length 1.4 width, with one long simple seta distodorsally. Carpus length twice merus length, length 3 width, with numerous small setae, membranously embedded, and three long unequally bifid setae in between ventrally. Propodus length 0.6 carpus length, length 2.7 width, with one slender simple seta distodorsally, with numerous small setae, membranously embedded, and two robust unequally bifid setae in between ventrally, with one simple seta distoventrally. Dactylus length 0.6 propodus length, length 4 width, with two slender setae medially, with numerous small setae, membranously embedded ventally. Unguis length 0.6 dactylus length, with two long, slender setae underneath unguis. PII (Fig. 21H) basis length 4.4 width. Ischium length about half basis length, length 2.1 width, with two simple setae distodorsally. Merus length 0.8 ischium length, length 1.6 width, with three simple setae of varying length distodorsally, with one long simple seta distoventrally. Carpus length 2.1 merus length, length 4.2 width, with nine long slender simple setae (one broken off) ventrally. Propodus length 0.7 carpus length, length 4.3 width, with one simple seta distodorsally, with three simple setae ventrally. Dactylus length 0.4 propodus length, length 5.5 width, with three simple setae medially. Unguis length half dactylus length, with two slender setae underneath unguis. PIII (Fig. 21I) basis length 4 width. Ischium length 0.6 basis length, length 1.7 width, with two simple setae of varying length (one underneath) distoventrally. Merus length 0.7 ischium length, length 1.8 width, with two simple setae of varying length distodorsally, with one long simple seta distoventrally. Carpus length 2.3 merus length, length 4.7 width, with nine long simple setae ventrally. Propodus length 0.7 carpus length. Dactylus length 0.3 propodus length, length 4.5 width. Unguis length 0.6 dactylus length, with two slender setae underneath unguis. PIV (Fig. 21J) basis length 3.8 width. Ischium length 0.8 basis length, length 3.5 width. Merus length 0.6 ischium length, length 2.1 width. Carpus length 1.8 merus length, length 4.4 width, with seven long slender simple setae ventrally. Propodus length 0.9 carpus length, length 6.8 width, with two simple setae (underneath) dorsally, with two simple setae ventrally. Dactylus length 0.3 propodus length, length 3.5 width. Unguis damaged. PV (Fig. 21K) basis length 4.6 width. Ischium length 0.8 basis length, length 3.6 width. Merus length half ischium length, length 1.7 width, with two simple setae distodorsally. Carpus length 2.2 merus length, length 4.6 width, with one small simple seta distodorsally, with one slender simple seta medially, with five long, slender simple setae ventrally. Propodus length 0.7 carpus length, length 4.3 width, with nine long simple setae dorsally. Dactylus length 0.4 propodus length, length 6 width. Unguis length 0.7 dactylus length, ventral claw underneath. PVII (Fig. 21L) basis length 5.2 width, with four long setae simple setae ventrally, with one simple seta distoventrally. Ischium length 0.7 basis length, length 2.9 width. Merus length half ischium length, length 1.7 width, with two simple setae distodorsally. Carpus length twice merus length, length 4.2 width, with one simple seta (one broken off) distodorsally, with four simple setae (two long, two broken off) ventrally. Propodus length 0.8 carpus length, length 5 width, with seven long simple setae dorsally, with one simple seta (broken off) distoventrally. Dactylus length 0.4 propodus length, length 6 width. Unguis length 0.7 dactylus length, ventral claw underneath. Op (Fig. 20G) length 1.2 width, with a strong ventral spine, posteriorly bent. Lateral and posterior margins rounded, with several (≥ 21) simple setae, setal size 0.1 Plt length. PlpIII (Fig. 20H) protopodite length 0.9 width, length 0.4 endopodite length. Exopodite half endopodite length, length 1.7 width, tapering in width distally, with numerous short simple setae laterally, with one somewhat longer simple seta distally. Endopodite length 1.6 width, with three long plumose setae distally, distal margin strongly rounded. Urp (Fig. 20I), biramous, length 0.25 Plt length, not projecting beyond Plt posterior margin. Protopodite damaged proximally, with one simple seta distally. Exopodite length 7.3 width, with two simple setae (one broken off) terminally. Endopodite length 3.2 exopodite length, length 6.4 width, with one simple seta laterally, with 6 setae (three long simple, three broken off) terminally.
Remarks: Nannoniscus pedro is most similar to species that are characterized by a slender body (body length ≥ 4.5 pereonite 1 width) as well as those possessing a uropodal exopodite and a ventral opercular spine. The new species most closely resembles N. hilario, but can be differentiated by the following characters: Mxp endopodite reaching mid of palpal article 3 (vs. distal third of palpal article 2 in N. hilario); Md incisor teeth acute (vs. rounded); Urp endopodite length 3.2 exopodite length (vs. 6.3); Op posterior margin with ≥ 21 setae (vs. ≤ nine). Nannoniscus pedro is also similar to N. magdae, but differs from the latter species as follows: robust setae of anterolateral tergites of pereonite 2 present (vs. absent in N. magdae); Md incisor teeth acute (vs. rounded). The new species can be distinguished from N. menziesi by the following characters: molar process of left and right Md with five and four distal spines, respectively (vs. 12 and 16 spines, respectively, in N. menziesi); Urp endopodite length 3.2 exopodite length (vs. 5.4). Nannoniscus pedro differs from N. perunis as follows: Urp endopodite length 3.2 exopodite length (vs. 7.8). Finally, the new species can be distinguished from N. meteori by the following characters: Mxp epipodite length 3.1 width (vs. 6.4 in N. meteori); Urp exopodite length 7.3 width (vs. 3.0); Urp endopodite length 6.4 width (vs. 3.2); Op posterior margin with ≥ 21 (vs. ≤ 15).
NANNONISCUS BRENKEI KAISER, BRIX & JENNINGS,(FIG. 23)
Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: AF031C17-94B8-4274-A079-D113BC1423BC.
Type fixation: Holotype, preparatory female, ZMH K-55370, 2.5 mm, designated here.
Material examined: Holotype: preparatory female (NB12_Iso070), 2.5 mm, CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 33 (start: 11°51’44’’N, 117°3’10’’W, 4133 m; end: 11°51’54’’N, 117°3’8’’W, 4133 m), date: 07/04/2012, ZMH K-55370.
Paratypes: Preparatory female (Na03), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20 (start: 11°50’9’’N, 117°58’29’’W, 4093 m; end: 11°50’11’’N, 116°58’0’’W, 4093 m), date: 21/03/2015, ZMH K-55369; ovigerous female (Na24), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 24 (start: 11°51’19’’N, 117°1’30’’W, 4093 m; end: 11°51’31’’N, 116°58’0’’W, 4093 m), date: 22/03/2015, ZMH K-55371; male (?), badly damaged (MA14_Iso258), CCZ, equatorial NE Pacific, MANGAN 14 expedition, RV Kilo Moana EBS, station 21 (start: 11°49’44.52’’N, 117°00’27.06’’W, 4132 m; end: 11°49’56.76’’N, 116°59’40.62’’W, 4136 m), date: 10/05/2014, ZMH K-55368.
Etymology: The name of the new species (brenkei, Latin genitive, male) is dedicated to Nils Brenke, builder of the Brenke sledge (“Berta”), in recognition of his passion for deep-sea isopod taxonomy.
Distribution: The species is only known from four stations in the eastern German claim of the CCZ (type locality) between 4093 and 4136 m depth.
Diagnosis: Body slender, length about 5.0 × pereonite 1 width; Mxp epipodite reaching mid of palpal article 3; Mxp lateral margin with a fringe of setae; molar process of both Md each with only a few (≤ 5) distal spines; Md incisor teeth rounded; pereonite 2 anterolateral tergites each with robust seta; pereonite 7 without ventral spine; Op with a ventral posteriorly bent spine, posterior margin with numerous (≥ 14) long simple setae; Urp biramous, not projecting beyond Plt posterior margin; Urp endopodite length ≤ 5.8 exopodite length; Plp 3 exopodite 0.6 endopodite length, length 2.5 width, strongly tapering in width distally.
Description of holotype and paratype female: Habitus (Fig. 23A). Body length 5.5 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Fig. 23A), length 0.8 width. Anterior and posterior slightly rounded, lateral margins straight. Antennae inserting frontolaterally in a deep fold. Pereonites 2–4 decreasing in width, pereonites 4–7 of similar width. Pereonite 1 length 0.3 width. Pereonite 1 and 2 of similar width, pereonite 2 length 1.1 pereonite 1 length. Pereonite 3 length 1.3 pereonite 2 length. Pereonite 4 length 1.2 pereonite 2 length. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of pereonite 2 each tipped with a robust seta, anterolateral tergites of pereonites 3 and 4 each with a simple seta. Pereonite 5 length 1.5 pereonite 1 length, anterior margin straight. Pereonites 6 and 7 dorsomedially fused, anterior margin of pereonite 6 convex. Plt length 0.2 body length, length 1.4 width, width 0.8 pereonite 1 width, posterior margin strongly rounded; anterior margin slightly concave. Urp length 0.3 Plt length, not projecting beyond posterior margin. AI (Fig. 23B), terminal article broken off, inferred from holotype (in situ). Length 0.1 body length, with five articles. First article circular and broadest, length 2.1 width, with one small broom seta and one simple seta distally. Second article length 0.9 article 1 length, length 1.6 width, with three long broom setae and one seta (broken off) distally. Article 3 minute, length 0.2 article 1 length, half as long as wide. Article 4 length 0.3 article 2 length, with a long distal projection, with one long broom seta and two simple setae distally. Article 5 length 0.5 article 1 length, as long as wide. AII (Fig. 23B) broken off, only podomere articles 1–4 present; articles quadrangular of similar length and width. Md (Fig. 23C, D), palp of left mandible broken off, of right mandible well developed, consisting of three articles extending beyond distal end of incisor process. Palpal article 2 of rMd length 2.5 article 1 length, with one simple seta and two fringes of small setule laterally. Terminal article length about one-third article 2 length, tapering distally, with several small setae ventrally and three somewhat longer setae terminally. Incisor process of rMd with seven rounded teeth, incisor of lMd with five rounded teeth. Lacinia mobilis of lMd with three teeth. Spine row of rMd with nine robust spines of varying size and several slender setae in between; size increasing proximally. Spine row of lMd with nine robust spines, dentation decreasing, spine size increasing proximally. Molar of rMd and lMd triangular; molar of rMd with five, of lMd with four long, serrate spines distally. Mxp (Fig. 23E), left and right Mxp connected by three retinacula (one broken off). Epipodite smooth, triangular, slender, length 3.6 width, reaching mid of palpal article 3. Palpal article 2 as wide as long. Article 3 length 0.8 article 2 length, width 1.2 length, with four robust sensory setae and two simple setae distally. Article 4 length 0.3 article 2 length, width half length. Article 5 length 0.2 article 2 length, width about half length, with two slender setae terminally. Endite distal margin with some robust, dentate setae and several fine setae laterally. Basis length 0.7 width. PI (Fig. 23F) basis length 4 width, with one simple seta dorsally and two simple setae ventrally. Ischium length 0.6 basis length, length 2.2 width, with one small simple seta ventrally. Merus length 0.6 ischium length, length 1.2 width, with one long simple seta distodorsally and one long simple seta distoventrally. Carpus length twice merus length, length 2.6 width, with one long simple seta distodorsally, with numerous small setae, membranously embedded, and three long unequally bifid setae in between ventrally. Propodus length 0.7 carpus length, length 2.7 width, with one slender simple seta distodorsally, with numerous small setae, membranously embedded, and one small robust unequally bifid seta ventrally. Dactylus length 0.6 propodus length, length 3.1 width, with three slender setae medially, with numerous small setae, membranously embedded ventrally. Unguis length about half dactylus length, with one long, slender seta underneath unguis. Op (Fig. 23G) length 1.3 width, with a strong ventral spine, posteriorly bent. Lateral margins rounded, posterior margin almost straight, with several (≥ 14) simple setae, setal size 0.2 Plt length. PlpIII (Fig. 23H) protopodite length 1.7 width, length 0.7 endopodite length. Exopodite 0.6 endopodite length, length 2.5 width, strongly tapering in width distally, with numerous short simple setae laterally, with one somewhat longer simple seta distally. Endopodite length 2.1 width, with three long plumose setae distally, distal margin strongly rounded. Urp (Fig. 23I), biramous, length 0.3 Plt length, not projecting beyond Plt posterior margin. Protopodite length 1.7 width, with one simple seta distally (broken off). Exopodite length 3.0 width, with two simple setae terminally. Endopodite length 5.8 exopodite length, length 6.0 width, with six setae (three broom setae, three simple of varying length) terminally.
Remarks: The new species is characterized by a slender body, robust spines on the anterolateral tergites of pereonite 2, biramous uropods and a ventral opercular spine, and thus most closely resembles N. hilario, N. menziesi, N. meteori, N. pedro and N. perunis. Nannoniscus brenkei is most similar to N. hilario, but can be differentiated from the latter as follows: molar process of left and right mandible with ≤ five spines distally (vs. ≥ nine spines in N. hilario); Op distal margin with ≥ 14 simple setae (vs. ≤ nine). Nannoniscus brenkei also resembles N. meteori, but differs from the latter as follows: Mxp lateral margin with numerous small simple setae (vs. setae lacking in N. meteori); Urp endopodite length 5.8 exopodite length (vs. 3.9). The new species can be differentiated from N. menziesi by the following characters: Mxp lateral margin with numerous small simple setae (vs. setae lacking in N. menziesi); molar process of left and right mandible with ≤ 5 spines distally (vs. ≥ 12). Nannoniscus brenkei can be distinguished from N. pedro as follows: Md incisor teeth rounded (vs. acute in N. pedro); Mxp lateral margin with numerous small simple setae (vs. setae lacking); Urp endopodite length ≥ 5.8 exopodite length (vs. ≤ 3.2). Finally, the new species differs from N. perunis by the following features: body length ≥ 5.0 pereonite 1 width (vs. ≤ 4.7 in N. perunis); Urp endopodite length 5.8 exopodite length (vs. 7.8); pereonites 3–4 tergites each with an anterolateral seta (vs. setae lacking) (see also the identification key, Table 4).
(FIGS 11–14)
Zoobank registration: urn:lsid:zoobank.org:act: B36BAA31-FE02-4E33-BB83-CA8444FB91E5.
Type fixation: Holotype, preparatory female, ZMH K-55375, 2.2 mm, designated here.
Material examined: Holotype: preparatory female (Na26), 2.2 mm, CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 171 (start: 14°2’41’’N, 130°5’57’’W, 5024 m; end: 14°3’12’’N, 130°4’36’’W, 5017 m), date: 17/04/2015, ZMH K-55375.
Paratypes: Preparatory female (Na12), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, same station as holotype, ZMH K-55374; preparatory female (NB12Iso99), CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 67 (start: 14°3’4’’N, 130°4’36’’W, 5021 m; end: 14°3’10’’N, 130°4’27’’W, 5021 m), date: 19/04/2012, ZMH K-55373; ovigerous female (Na28), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, same station as holotype, ZMH K-55376; juvenile male (Na49), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, same station as holotype, ZMH K-55377.
Etymology: The new species (magdae, Latin genitive, feminine) is named in honour of Magdalena Błażewicz for her invaluable help onboard the SO239 Ecoresponse voyage, and her contributions to the taxonomy and biodiversity of deep-sea peracarids.
Distribution: Based on the material available (four specimens), this species has a restricted distribution and is only known from the French licence area of the CCZ, between 5017 and 5024 m depth.
Diagnosis: Body slender, length about 4.8 × pereonite 1 width; Mxp lateral margin with numerous small setae; Mxp epipodite reaching mid of palpal article 3; molar process of both Md with ≥ nine distal spines each; Md incisor teeth rounded; pereonite 2 anterolateral tergites devoid of setae; pereonite 7 without ventral spine; Op with ventral posteriorly bent spine, posterior margin with numerous (≥ 17) long simple setae; Urp biramous, not projecting beyond Plt posterior margin; Urp endopodite length about 2.1 exopodite length.
Description of holotype and paratype female: Habitus (Figs 11B, D, 14A–C), body length 4.8 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Figs 11B, 14D–E) as long as wide (measured from lateral view). Anterior margin straight, posterior and lateral margins slightly rounded. Antennae inserting frontolaterally in deep fold. Pereonites 1–4 gradually flattening, then abruptly flattening from pereonite 4 to 5. Pereonites 1–3 of similar width, gradually decreasing in width from 3 to 7; pereonite 1 length 0.4 width. Pereonite 2 width 0.5 pereonite 1 width, length 1.2 pereonite 1 length. Pereonites 2 and 3 of similar length; pereonite 4 length 1.1 pereonite 1 length. Pereonites 1–4 anterior margins frontally directed, without setation. Pereonite 5 length 1.1 pereonite 1 length, anterior margin straight. Pereonites 6–7 dorsomedially fused, pereonite anterior margin slightly convex. Plt length 0.2 body length, length 1.5 width; width 0.7 pereonite 1 width, posterior margin strongly rounded; anterior margin straight. Urp length 0.3 Plt length, not projecting beyond posterior margin. AI (Fig. 11A) length 0.1 body length, with five articles. First article circular and broadest, with one small broom seta distally. Second article length twice width, with three broom setae (one broken off) and one small simple seta distally. Article 3 minute, length 0.2 article 2 length, as long as wide. Article 4 length 0.3 article 2 length, with long distal projection reaching mid of article 5, with two simple setae of varying size distally. Article 5 length 0.9 article 2 length, length 1.6 width, with one aestetasc terminally. AII (Fig. 11C) length 0.4 body length, with six podomere and seven flagellar articles. Podomere articles 1–4 short; article 1 with one simple seta distally; article 3 with two simple setae distally, article 4 with one simple seta distally. Article 5 longest, length 1.3 articles 1–4 length, length approximately 4.1 width, with two simple setae laterally. Article 6 length 0.8 article 5 length, length 3.3 width, with two broom setae of varying size and one long simple seta distally. Flagellar article 1 longest, conjoint with two setal positions (fusion of three articles), length 0.9 podomere article 6 length, length 4.6 width, with two simple setae laterally. Flagellar articles 2–7 decreasing in length and width distally; each article with 1–3 short simple setae distally. Article 7 with 5 long slender setae terminally. Md (Fig. 11E, F), palp of left and right mandible well developed, consisting of three articles reaching mid of incisor. Palpal article 2 of rMd length 1.7 article 1 length, with two simple setae laterally. Terminal article length 0.4 article 2 length, tapering distally, with several (≥ nine) small setae ventrally and three somewhat longer setae terminally. Incisor process of rMd with three rounded teeth, incisor of lMd with rounded three teeth. Lacinia mobilis of lMd with three teeth. Spine row of rMd with 10 robust spines and several slender setae in between; dentation decreasing and setal size increasing proximally. Spine row of lMd with ten robust spines and several slender setae in between, dentation decreasing, seta length increasing proximally. Molar of rMd and lMd triangular; molar of rMd and lMd each with nine long, serrate spines distally. Mxp (Fig. 11G), left and right Mxp connected by three retinacula. Epipodite smooth, triangular, slender, length 3.1 width, reaching mid of palpal article 3. Palpal article 1 short, width 1.6 length, with several small setae lateral. Article 2 length 1.9 article 1 length, as long as wide, with several small setae laterally. Article 3 length 1.6 article 1 length, width 0.9 length, with four robust sensory setae distally and two simple setae laterally. Article 4 as long as article 1, width 0.5 length, with distal projection reaching mid of article 5, with three slender setae distally. Article 5 length 0.6 article 1 length, width 0.4 length, with three slender setae terminally. Endite distal margin with some robust, dentate setae and several fine setae laterally. Basis triangular, length 0.7 width. PI (Fig. 12C) basis length 2.7 width. Ischium length about half basis length, length 2.2 width, with two simple setae distodorsally, with one simple seta ventrally. Merus length 0.7 ischium length, length 1.4 width, with two simple seta distodorsally, with one long simple setae distoventrally. Carpus length 1.6 merus length, length 2.4 width, with one simple seta distodorsally, with row of six simple setae ventrally. Propodus length 0.9 carpus length, length 3.8 width, with one simple seta dorsally, with numerous small setae, membranously embedded, and two small unequally bifid setae in between ventrally. Dactylus length about half propodus length, length 4.5 width, with one small simple setae medially. Unguis length half dactylus length, with two long, slender setae underneath unguis. PII (Fig. 12D) basis length 3.7 width, with one simple seta distoventrally. Ischium length about half basis length, length twice width, with five simple setae dorsally, with one simple seta distodorsally. Merus length 0.8 ischium length, length 1.5 width, with one simple seta (broken off) distodorsally, with one simple seta distoventrally. Carpus length 2.3 merus length, length 3.9 width, with six long slender simple setae and two long robust setae ventrally. Propodus length 0.6 carpus length, length 3.7 width, with two simple setae dorsally, with numerous small setae, membranously embedded, and three simple setae in between ventrally. Dactylus length 2.4 propodus length, length 3 width, with two simple setae medially, with numerous small setae ventrally. Unguis length 0.7 dactylus length, with two slender setae underneath unguis. PIII (Fig. 12E) damaged between basis and ischium. Basis length 4.4 width. Ischium length about half basis length, length 2.3 width, with one simple seta distodorsally, with one simple seta ventrally. Merus length 0.8 ischium length, length 1.8 width, with one small seta distodorsally, with one somewhat longer seta distoventrally. Carpus length 2.3 merus length, length 4.5 width, with 11 long slender setae (four broken off) ventrally. Propodus length 0.7 carpus length, length 4.3 width, with three long simple setae dorsally. Dactylus length 0.3 propodus length, length 2.3 width. Unguis damaged, as long as dactylus. PIV (Fig. 12F) basis length 5.9 width, with one simple seta ventrally. Ischium length 0.6 basis length, length 3.8 width. Merus length 0.6 ischium length, length 2.2 width, with one small simple seta distodorsally, with one long simple seta distoventrally. Carpus length 2.2 merus length, length 4.7 width, with nine long slender simple setae ventrally. Propodus length 0.7 carpus length, length 5 width, with numerous small setae and four simple seta ventrally. Dactylus length 0.4 propodus length, length 3.5 width. Unguis length 0.6 dactylus length, ventral claw length 0.3 ungius length. PV (Fig. 12G) basis length 4.9 width. Ischium length 0.8 basis length, length 3.1 width, with two long simple setae dorsally. Merus length about half length, length 1.8 width, with three simple setae (two long, one somewhat shorter) distodorsally. Carpus length twice merus length, length 3.6 width, with four long slender simple setae dorsally, with six long slender simple setae ventrally. Propodus length 0.6 carpus length, length 3.2 width, with four long simple setae dorsally, with five long simple setae ventrally. Dactylus length half propodus length, length 3 width. Unguis length 0.8 dactylus length, ventral claw length 0.6 ungius length. PVI (Fig. 12H) basis length 5.1 width, with three long simple setae ventrally. Ischium length 0.7 basis length, length 3.4 width. Merus length half ischium length, length 1.6 width, with two long simple setae distodorsally. Carpus length 2.4 merus length, length 4.1 width, with four long slender simple setae (one broken off) ventrally. Propodus length 0.6 carpus length, length 3.5 width, with seven long simple setae dorsally, with two simple setae of varying size ventrally. Dactylus length half propodus length, length 2.2 width. Unguis length 0.6 dactylus length, with two slender setae of varying size underneath unguis. PVII (Fig. 12I) slightly damaged between ischium and merus. Basis length 3.2 width. Ischium length 0.8 basis length, length 2.9 width, with one simple seta distodorsally. Merus length 0.4 ischium length, length 1.3 width, with one seta (broken off) distodorsally. Carpus length 2.4 merus length, length 3.1 width, with five slender simple setae (four long, one somewhat shorter) ventrally. Propodus length 0.7 carpus length, length 3.8 width, with seven long simple setae dorsally. Dactylus length 0.4 propodus length, length 4.5 width, with three simple setae medially. Unguis length 0.9 dactylus length, with two slender setae underneath unguis. Op (Fig. 11H) length 1.2 width, with strong ventral spine, posteriorly bent. Lateral margin rounded, posterior margin almost straight, with several (≥ 17) simple setae, setal size 0.3 Plt length. PlpIII (Fig. 11I), protopodite length 0.7 proximal width, length 0.4 endopodite length. Exopodite 0.5 endopodite length, length 1.6 width, width tapering distally, with numerous short simple setae laterally and one somewhat longer distally. Endopodite 1.2 length 1.5 width, with three long plumose setae distally, distal margin strongly rounded. PlpIV (Fig. 11J), protopodite rectangular, as long as wide, length 0.4 endopodite length. Exopodite slender, length 0.7 endopodite length, length 5 width, with several thin setules laterally (outer margin) and one long robust plumose seta distally. Endopodite ovoid-shaped, length twice width. PlpV (Fig. 11K), small oval lobe, without setation. Length twice proximal width, width gradually tapering towards distal end. Urp (Fig. 11L) biramous, length 0.2 Plt length, not projecting beyond Plt posterior margin. Protopodite length 1.5 proximal width, with three long simple setae distally. Exopodite length 0.5 protopodite length, length 4.5 width, with two long simple setae terminally. Endopodite length 2.1 exopodite length, length 3.8 width, with two simple setae (broken off), two long simple setae and two long broom setae terminally.
Description of male paratype: Habitus (Fig. 13). Body length 5.3 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Fig. 13A) length equals width. Anterior, lateral and posterior margins rounded. Antennae inserting frontolaterally in deep fold. Pereonites 3–6 decreasing in width. Pereonite 1 length 0.3 width. Pereonites 1–2 of similar width; pereonite 2 length 1.6 pereonite 1 length. Pereonites 2–3 of similar length. Pereonite 3 width 0.9 pereonite 1 width. Pereonites 2–5 of similar length. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of perenonite 1–4 each tipped with simple seta. Pereonites 4–7 of similar width, width 0.8 pereonite 1 width. Pereonite 5 anterior margin straight. Pereonites 6–7 dorsomedially fused, pereonite 6 anterior margin straight. Plt 0.2 body length, length 1.2 width, width 0.8 pereonite 1 width; posterior margin strongly rounded, anterior margin slightly concave. Urp not projecting beyond posterior margin. PlpI (Fig. 13B), length 2.5 proximal width. Distal projection width 0.5 proximal width, lateral margins straight. Lateral lobes rounded. Distal margins almost straight, with three simple setae. PlpII (Fig. 13C), sympod length 2.2 width, outer margin rounded, with one simple seta distally; inner margin straight. Endopod inserting 0.3 from distal tip of sympod. Stylet length 0.7 sympod length, slightly curved, distal end not extending beyond distal tip of sympod. Exopod short and rounded, inserting 0.1 from distal tip of sympod.
Remarks: The new species most closely resembles N. hilario, N. menziesi and N. perunis, but differs from these species by lacking robust setae on the anterolateral tergites of pereonite 2 and a markedly longer uropodal exopodite (Urp endopodite/exopodite length ratio 2.1 vs. ≥ 5.6 in the remaining species). Nannoniscus magdae can be furthermore distinguished from N. hilario as follows: Mxp endopodite reaching mid of palpal article 3 (vs. distal third of palpal article 2 in N.hilario); Op posterior margin with ≥ 17 simple setae (vs. ≤ 9). Additional characters to distinguish the new species from N. menziesi are: Mxp lateral margin with numerous small setae (vs. Mxp lateral margin lacking setae in N. menziesi); Md incisor teeth rounded (vs. acute). Nannoniscus magdae is also similar to N. meteori, but can be differentiated as follows: Mxp lateral margin with numerous small setae (vs. Mxp lateral margin lacking setae in N. meteori). The description of the male characteristics of N. magdae is based on a juvenile specimen, which can differ considerably from the terminal males (Riehl et al., 2012). However, since the specimen is the only male found for the new species, we found it to be a valuable addition to the female description.
NANNONISCUS MENOTI KAISER, JANSSEN &(FIGS 15–19)
Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: 8BFC86F5-43FE-41AF-B49B-2793B2E7C3B8.
Type fixation: Holotype, ovigerous female, ZMH K-55354, 3.6 mm, designated here.
Material examined: Holotype: ovigerous female (Na27), 3.6 mm, CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 171 (start: 14°2’41’’N, 130°5’57’’W, 5024 m; end: 14°3’12’’N, 130°4’36’’W, 5017 m), date: 17/04/2015, ZMH K-55354.
Paratype: Preparatory female (Na18), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20 (start: 11°50’9’’N, 117°58’29’’W, 4093 m; end: 11°50’11’’N, 116°58’0’’W, 4093 m), date: 21/03/2015, ZMH K-55356; preparatory female (Na06), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 117 (start: 13°52’19’’N, 123°15’27’’W, 4498 m; end: 13°52’37’’N, 123°14’16’’W, 4521 m), date: 07/04/2015, ZMH K-55352; adult male (MA14_Iso272), CCZ, equatorial NE Pacific, KM14 expedition, RV Kilo Moana, EBS, station 38 (start: 11°47 52’’N, 117°30’31’’W, 4363 m; end: 11°48’3’’N, 117°29’45’’W, 4373 m), date: 13/05/2014, ZMH K-55350; preparatory female (Na42/Iso1120), APEI-6, equatorial NE Pacific, ABYSSLINE-2 expedition, RV Thomas G. Thompson, EBS, station APEI-6#1 (start: 19°27’52’’N, 120°1’31’’W, 4099 m; end: 120°0’58’’N, 120°0’58’’W, 4076 m), date: 20/03/2015, ZMH K-55355; preparatory female (NB12_Iso068), CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 33 (start: 11°51’44’’N, 117°3’10’’W, 4133 m; end: 11°51’54’’N, 117°3’8’’W, 4133 m), date: 07/04/2012, ZMH K-55353; preparatory female (MA14_Iso352), CCZ, equatorial NE Pacific, MA14 expedition, RV Kilo Moana, EBS, station 39 (start: 11°49’37’’N, 117°30’49’’W, 4361 m; end: 11°49’47’’N, 117°30’5’’W, 4343 m), date: 13/05/2014, ZMH K-55351; preparatory female (Na40/Iso1005), CCZ, equatorial NE Pacific, ABYSSLINE-2 expedition, RV Thomas G. Thompson, EBS, station S11 (start: 12°2’43.08’’N, 117°25’26’’W, 4223 m; end: 12°3’1.44’’N, 117°24’17’’W, 4235 m), date: 16/03/2015, ZMH K-55349; ovigerous female (MA13_ Iso453), CCZ, equatorial NE Pacific, MA13 expedition, RV Kilo Moana, EBS, station 90 (start: 11°49.718’N, 117°30.278’W, 4340 m; end: 11°49.906’N, 117°29.395’W, 4357 m), date: 03/05/2013, ZMH K-55348.
Etymology: The new species (menoti, Latin genitive, masculine) is named after Lenaick Menot, leader of the French party of the BIONOD expedition, for joint actions sieving and sorting the mud.
Distribution: This species has a wide distribution across the CCZ, being obtained from the eastern German, OMS, GSR and French (type locality) licence areas, as well as APEI-6 between 4076 and 5024 m depth.
Diagnosis: Body slender, length about 5.1 × pereonite 1 width; Mxp lateral margin with numerous small setae; Mxp epipodite reaching mid of palpal article 3; molar process of left Md with ≥ ten distal spines; Md incisor teeth rounded; pereonite 2 anterolateral tergites each with robust seta; pereonite 2 anterolateral tergites each with robust seta; pereonite 7 without ventral spine; Op with a ventral posteriorly bent spine, posterior margin with numerous (≥ 15) short simple setae; Urp uniramous, not projecting beyond Plt posterior margin; male PlpI without hook-like projections distally.
Description of holotype and paratype female: Habitus (Figs 15D, 18), pereonites 2 and 3 damaged. Body length 5.1 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Figs 15D, 18D, E), length 0.9 width. Anterior and lateral margins straight, posterior m a r g i n s l i g h t l y r o u n d e d. A n t e n n a e i n s e r t i n g frontolaterally in a deep fold. Pereonite 2 widest, pereonites 2–7 decreasing in width. Pereonite 1 width 0.8 pereonite 2 width, length 0.4 width. Pereonites 2 and 3 of similar length and width, length approximately 1.3 pereonite 1 length. Pereonite 4 longest, length 1.7 pereonite 1 length. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of pereonite 2 each tipped with a robust seta, pereonites 3–4 each with a slender seta. Pereonite 5 width 0.9 pereonite 1 width, length 1.6 pereonite 1 length; pereonite 5 anterior margin slightly convex. Pereonites 6–7 dorsomedially fused, pereonite 6 anterior margin convex. Plt length 0.2 body length, length 1.4 width; width 0.9 pereonite 1 width, posterior margin strongly rounded; anterior margin straight. Urp length 0.2 Plt length, not projecting beyond posterior margin. AI described in situ from CLSM (Fig. 18A, E), from CLSM. Length 0.1 body length, with five articles. First article broadest, length twice width, with one broom seta distally. Second article as long as article 1, length 2.4 width, with two broom setae distally. Article 3 minute, length 0.2 article 1 length, as long as wide. Article 4 length 0.3 article 1 length, with a long distal projection reaching mid of article 5. Article 5 length 0.7 article 2 length, length 1.8 width. AII (Fig. 15A) length 0.4 body length, with six podomere and 11 flagellar articles. Podomere article 1 broken off, described from CLSM (Fig. 18A). Articles 1–4 short; article 3 with three simple setae and one small robust spine distally, article 4 with one simple seta distally. Article 5 length 1.5 articles 1–4 length, length approximately 5.8 width, with six simple setae laterally. Article 6 longest, length 1.1 article 5 length, length 6 width, with three simple setae laterally, with four broom setae of varying size and two long simple setae distally. Flagellar article 1 longest, conjoint with one setal position (fusion of 2 articles), length half podomere article 6 length, length 4.5 width, with two simple setae laterally. Flagellar articles 3–11 decreasing in length and width distally; each article with 1–3 simple setae distally. Article 11 with six long slender setae terminally. Md (Fig. 15B, C), palp of left and right Md broken off. Incisor process of rMd and lMd with four rounded teeth each. Lacinia mobilis of lMd with three teeth. Spine row of rMd with 12 robust spines, dentation decreasing proximally. Spine row of lMd with ten robust spines and several slender setae in between, dentation decreasing, seta size increasing proximally. Molar of lMd triangular, with ten serrate spines of varying size distally. MxII (Fig. 15E), outer margin of mesial endite with several setae of varying length, distal margin with numerous long setae of varying length. Mesial endite as long as lateral endite. Lateral endite and middle endite each with three strong setae distally. Mxp (Fig. 15F), left and right Mxp connected by three retinacula. Epipodite smooth, triangular, slender, length 3.1 width, reaching mid of palpal article 3. Palpal article 1 short, with several small setae laterally. Article 2 length 2.4 article 1 length, width 0.9 length, with several small setae laterally. Article 3 length 1.1 article 1 length, width 1.6 length, with four robust sensory setae (one broken off) and one somewhat longer simple seta distally. Article 4 length 1.4 article 1 length, width 0.3 length, with a distal projection reaching mid of article 5, with two slender setae distally. Article 5 length 0.8 article 1 length, width 0.3 length, with three slender setae of varying size terminally. Endite distal margin with some robust, dentate setae and several fine setae laterally. Basis quadrangular, length 0.9 width. PI (Fig. 16B) basis length 3.4 width, one small simple seta ventrally. Ischium 0.6 basis length, length 2.6 width, with one long simple seta distodorsally. Merus length 0.6 ischium length, length 1.4 width, with two long simple setae distodorsally. Carpus length 2.2 merus length, length 3.7 width, with one simple seta distodorsally, with five unequally bifid setae and numerous small setae ventrally. Propodus length 0.6 carpus length, length 3 width, with one simple seta dorsally, with numerous small setae, membranously embedded, ventrally, with one simple seta distoventrally. Dactylus length about half propodus length, length 3.7 width, with three slender setae medially. Unguis length half dactylus length, with two long, slender setae underneath unguis. PII (Fig. 16C) basis length 3.8 width. Ischium length about half basis length, length 2.3 width, with one long simple seta distodorsally. Merus length 0.7 ischium length, length 1.5 width, with two simple setae of varying length distodorsally, with one simple seta ventrally, and one simple seta distoventrally. Carpus length 2.6 merus length, length 4.3 width, with seven unequally bifid setae ventrally increasing in size distally. Propodus length 0.6 carpus length, length 4 width, with one long simple seta distodorsally, with numerous small setae, membranously embedded, and two small unequally bifid setae ventrally. Dactylus length 0.4 propodus length, length 3.3 width, with numerous small setae, membranously embedded ventrally. Unguis length half dactylus length, with two long, slender setae underneath unguis. PIII (Fig. 16D) basis length 4.7 width, with one long robust simple seta distoventrally. Ischium 0.4 basis length, length 2.1 width, with one simple seta distodorsally. Merus length 0.9 ischium length, length 1.8 width, with one simple seta distodorsally, with one simple seta (broken off) distoventrally. Carpus length 2.5 merus length, length 5.4 width, with eight robust setae (three unequally bifid setae, five simple) ventrally. Propodus length 0.6 carpus length, length 4.8 width, with six long simple setae (four broken off) dorsally, with numerous small setae, membranously embedded, and two small unequally bifid setae ventrally. Dactylus length 0.4 propodus length, length 6 width, with two simple setae medially. Unguis length 0.6 dactylus length, with two long, slender setae underneath unguis. PIV (Fig. 16E) basis length 5.5 width, with three simple setae dorsally, with three simple setae ventrally. Ischium length half basis length, length 2.9 width, with one simple seta distodorsally, with one simple seta ventrally. Merus length 0.6 ischium length, length twice width, with one long simple seta distodorsally, with one long simple seta distoventrally. Carpus length 2.5 merus length, length 6.4 width, with five simple setae (underneath) dorsally, with nine slender simple setae ventrally, increasing in size distally. Propodus length 0.6 carpus length, length 4.8 width, with six simple setae (four broken off) dorsally, with numerous small setae, membranously embedded, and four small unequally bifid setae ventrally. Dactylus length 0.4 propodus length, length 6 width, with two simple setae medially, with numerous small setae ventrally. Unguis length 0.3 dactylus length, with two slender setae underneath unguis. PV (Fig. 16F) basis length 4.5 width, one long simple seta distodorsally. Ischium length 0.8 basis length, length 3.6 width, with two long simple setae dorsally. Merus length half ischium length, length 1.8 width, with two simple setae of varying size distodorsally, with one small simple seta distoventrally. Carpus length 2.1 merus length, length 3.4 width, with six long simple setae (one broken off) ventrally. Propodus length 0.7 carpus length, length 2.9 width, with seven long simple setae (underneath) dorsally, with four long simple setae ventrally. Dactylus length half propodus length, length 3.5 width. Unguis length 0.7 dactylus length, with two setae of varying size underneath unguis. PVI (Fig. 16G) basis length 3.1 width, with one simple seta distoventrally. Ischium as long as basis, length 2.7 width, with one small simple seta ventrally. Merus length 0.4 ischium length, length 1.5 width, with two simple setae (one broken off) distodorsally, with one small simple seta ventrally. Carpus length 2.4 merus length, length 3.8 width, with one slender setae distodorsally, with three long simple setae ventrally. Propodus length 0.8 carpus length, length 5 width, with eight long setae dorsally, with two long setae distoventrally. Dactylus length half propodus length, length 5.3 width. Unguis length 0.8 dactylus length, with two slender seta underneath unguis. PVII (Fig. 16H) basis length 4.5 width. Ischium damaged, length 0.6 basis length, length 2.4 width. Merus length half ischium length, length 1.3 width. Carpus length 2.4 merus length, length 3.9 width, with eight long slender simple setae dorsally, with three simple setae dorsally, with one simple seta distodorsally, with three setae (two simple, one unequally bifid) of varying size ventrally. Propodus length 0.7 carpus length, length 4 width, with five long simple setae dorsally, with one simple seta ventrally, with one robust simple seta distoventrally. Dactylus length half propodus length, length 3.1 width. Unguis length 0.8 dactylus length, with two slender setae underneath unguis. Op (Fig. 15G), drawn in situ. Length 1.4 width, with a strong ventral spine, posteriorly bent. Lateral and posterior margins, with several (≥ 15) simple setae, setal size 0.1 Plt length. PlpIII (Fig. 15H) protopodite length 0.9 width, length 0.3 endopodite length. Exopodite half endopodite length, length 1.8 width, tapering in width distally, with numerous short simple setae laterally and one somewhat longer seta distally. Endopodite length 1.8 width, with two long plumose setae distally, distal margin rounded. PlpIV (Fig. 15I) protopodite rectangular, length 0.6 width, length 0.2 endopodite length. Exopodite slender, length 0.7 endopodite length, length 7.2 width, with several thin setules laterally (outer margin) and one long robust plumose seta distally. Endopodite length 2.6 width, distal end tapering in an acute angle. PlpV (Fig. 15J) small oval lobe, without setation, about as long as pleopod 4 endopodite. Length 2.2 proximal width, width tapering towards distal end. Urp (Fig. 15K) uniramous, length 0.2 Plt length, not projecting beyond Plt posterior margin. Protopodite oval, length 1.4 width, with five simple setae of varying length laterally. Endopodite length 1.6 protopodite length, length 5.3 width, with one broom seta laterally, with three broom setae and four simple setae (three broken off) terminally.
Description of male paratype: Habitus (Figs 17A, 19). Body length 5.7 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Figs 17A, 19D, E), length 1.1 width. Anterior and lateral margins rounded, posterior margin almost straight. Antennae inserting frontolaterally in a deep fold. Pereonites 2–5 decreasing in width. Pereonite 1 length 0.3 width. Pereonite 2 widest, width 1.1 pereonite 1 width, length 2.1 pereonite 1 length. Pereonites 2–3 of similar length. Pereonites 4–7 of similar length, pereonite 4 length 1.9 pereonite 1 length. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of perenonite 2 each tipped with a robust seta, anterolateral tergites of pereonites 3–4 each with simple seta. Pereonites 5–7 of similar width, width 0.8 pereonite 1 width. Pereonite 5 anterior margin straight. Pereonites 6–7 dorsomedially fused, pereonite 6 anterior margin straight. Plt 0.2 body length, length 1.4 width, width 0.7 pereonite 1 width; posterior margin strongly rounded, anterior margin slightly concave. Anus (Fig. 19B, F) covered by anus valves laterally. Urp inserting closely to the anus valves, length 0.2 Plt length, not projecting beyond posterior margin. PlpI (Figs 17B, 19B, F), length 3.2 proximal width. Distal projection width 0.4 proximal width, lateral margins slightly concave. Lateral lobes rounded, with five small setae inserting distally from each lateral lobe. Distal margins strongly rounded, with four simple setae of varying length each. PlpII (Fig. 17C), sympod length 2.5 width, outer margin rounded, with six long slender simple setae distally, with numerous small setae laterally; inner margin straight. Endopod inserting 0.3 from distal tip of sympod. Stylet length 0.6 sympod length, slightly curved, distal end not extending beyond distal tip of sympod. Exopod short and rounded, inserting 0.1 from distal tip of sympod. PlpIII (Fig. 17D), protopodite length 1.3 width, length half endopodite length. Exopodite half endopodite length, length 1.3 width, tapering in width distally, with numerous short simple setae laterally and one somewhat longer seta distally. Endopodite length 1.6 width, with three long plumose setae distally, distal margin rounded. PlpIV (Fig. 17E), protopodite rectangular, length 0.6 width, length 0.3 endopodite length. Exopodite slender, length 0.7 endopodite length, length 6.8 width, with several thin setules laterally (outer margin) and one long robust plumose seta distally. Endopodite length 1.8 width, distal margin rounded.
Remarks: The new species is distinct from most other species in the genus by possessing uniramous uropods. Besides N. menoti, only N. ovatus lacks a uropodal exopodite. The new species can be differentiated from N. ovatus as follows: body length 5.1 pereonite 1 width in female (vs. 4.7 in N. ovatus); Op posterior margin with ≥ 15 setae (vs. ≤ 9); Mxp lateral margin with numerous small setae (vs. Mxp lateral margin lacking setae); male PlpI without hook-like projections distally (vs. 3).
NANNONISCUS PEDRO KAISER, BRIX & KIHARA,(FIGS 20–22)
Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: 820608B2-7BAA-43B1-8B40-3A5561937B8B.
Type fixation: Holotype, preparatory female, ZMH K-55358, 3.4 mm, designated here.
Material examined: Holotype: preparatory female (Na08), 3.4 mm, CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 133 (start: 13°50‘45’’N, 123°15’39’’W, 4516 m; end: 13°51’8’’N, 123°14’8’’W, 4427 m), date: 10/04/2015, ZMH K-55358.
Paratypes: Ovigerous female (Na11), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 171 (start: 14°2’41’’N, 130°5’57’’W, 5024 m; end: 14°3’12’’N, 130°4’36’’W, 5017 m), date: 17/04/2015, ZMH K-55362; preparatory female (Na04), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20 (start: 11°50’9’’N, 117°58’29’’W, 4093 m; end: 11°50’11’’N, 116°58’0’’W, 4093 m), date: 21/03/2015, ZMH K-55361; preparatory female (Na05), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20, ZMH K-55365; preparatory female (Na22), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 24 (start: 11°51’19’’N, 117°1’30’’W, 4093 m; end: 11°51’31’’N, 116°58’0’’W, 4093 m), date: 22/03/2015, ZMH K-55363; preparatory female (NB12_Iso_290), CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 43 (start: 11°48’12’’N, 117°32’3’’W, 4358 m; end: 11°48’20’’N, 117°31’57’’W, 4358 m), date: 09/04/2012, ZMH K-55360; preparatory female (NB12_Iso_330), CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 43, ZMH K-55364; preparatory female (MA13_Iso593), CCZ, equatorial NE Pacific, MA13 expedition, RV Kilo Moana, EBS, station 90 (start: 11°49.718’N, 117°30.278’W, 4340 m; end: 11°49.906’N, 117°29.395’W, 4357 m), date: 03/05/2013, ZMH K-55359; preparatory female (MA13_ Iso049), CCZ, equatorial NE Pacific, MA13 expedition, RV Kilo Moana, EBS, station 07 (start: 11°51.503’N, 117°01.205’W, 4131 m; end: 11°51.756’N, 117°00.171’W, 4121 m), date: 12/04/2013, ZMH K-55357; female, badly damaged (MA14_Iso319), CCZ, equatorial NE Pacific, MA14 expedition, RV Kilo Moana, EBS, station 39 (start: 11°49’37’’N, 117°30’49’’W, 4361 m; end: 11°49’47’’N, 117°30’5’’W, 4343 m), date: 13/05/2014, ZMH K-55367; male, badly damaged (MA14_Iso242), CCZ, equatorial NE Pacific, MA14 expedition, RV Kilo Moana, EBS, station 39, date: 13/05/2014, ZMH K-55366.
Etymology: The name is a noun in apposition, and dedicated to Pedro Martinez Arbizu, Principal Investigator of the JPIO EcoResponse expedition, for his drive and commitment to the exploration of the abyssal manganese nodule fauna.
Distribution: The species has a broad distribution across the CCZ, being collected from the eastern German, GSR (type locality) and French licence areas between 4093 and 5024 m depth.
Diagnosis: Body slender, length about 5.5 × pereonite 1 width; Mxp epipodite reaching mid of palpal article 3; Mxp lateral margin lacking fringe of setae; molar process of both Md each with only a few (≤ 5) distal spines; Md incisor teeth acute; pereonite 2 anterolateral tergites each with robust seta; pereonite 7 without ventral spine; Op with a ventral posteriorly bent spine, posterior margin with numerous (≥ 21) long simple setae; Urp biramous, not projecting beyond Plt posterior margin; Urp endopodite length ≥ 3.2 exopodite length.
Description of holotype and paratype female: Habitus (Figs 20A, B, 22), body length 5.5 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Figs 20A, 22D–E), length 0.7 width. Anterior and posterior margins straight, lateral margin slightly rounded. Antennae inserting frontolaterally in a deep fold. Body abruptly flattening from pereonite 4 to 5. Pereonites 2–4 decreasing in width, pereonites 4–7 of similar width. Pereonite 1 length 0.3 width. Pereonite 1 and 2 of similar width, pereonite 2 length 1.7 pereonite 1 length. Pereonites 3 and 4 of similar length, length 1.2 pereonite 2. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of pereonite 2 each tipped with a robust seta, anterolateral tergites of pereonites 3 and 4 each with a simple seta. Pereonite 5 length 1.8 pereonite 1 length, anterior margin straight. Pereonites 6 and 7 dorsomedially fused, anterior margin of pereonite 6 convex. Plt length 0.2 body length, length 1.2 width, width 0.9 pereonite 1 width, posterior margin strongly rounded; anterior margin concave. Urp length 0.3 Plt length, not projecting beyond posterior margin. AI (Fig. 20C), terminal article broken off, inferred from CLSM (Fig. 22A, E). Length 0.1 body length, with five articles. First article circular and broadest, length 2.3 width. Second article length 0.7 article 1 length, length 1.8 width, with two simple setae distally. Article 3 minute, length 0.1 article 1 length, as long as wide. Article 4 length 0.1 article 2 length, with a long distal projection reaching mid of article 5, with one simple seta distally. Article 5 length 0.9 article 2 length, length 1.2 width, with one aestetasc terminally. AII (Fig. 20D) length 0.4 body length, with six podomere and nine flagellar articles. Podomere articles 1–4 short. Article 5 longest, length 1.2 articles 1–4 length, length 5.4 width. Article 6 length 0.9 article 5 length, length 5.6 width. Flagellar article 1 longest, conjoint (fusion of three articles), length 0.6 podomere article 6 length, length 4.8 width. Flagellar articles 2–4 of similar length, length 0.2 flagellar article 1 length. Flagellar 5 article longest, length 0.3 flagellar article 1 length. Flagellar articles 1–9 decreasing in width distally, each article with 0–3 simple setae distally. Article 9 with seven long slender setae terminally. Md (Fig. 21D, E), palp of right mandible damaged, of left mandible well developed, consisting of three articles almost reaching mid of incisor. Palpal article 2 of lMd length 1.2 article 1 length, with two simple setae laterally. Terminal article length about half article 2 length, tapering distally, with several small setae ventrally and two somewhat longer setae terminally. Incisor process of rMd with three acute teeth, incisor of lMd with six acute teeth and one subdistal tooth. Lacinia mobilis of lMd with three teeth. Spine row of rMd with ten robust spines of varying size and several slender setae in between; dentation decreasing proximally. Spine row of lMd with eight robust spines and several slender setae in between, dentation decreasing, spine size increasing proximally. Molar of rMd and lMd triangular; molar of rMd with four, of lMd with five long, serrate spines distally. MxI (Fig. 21F) outer endite with 17 robust spine-like setae distally. Outer margin with several slender setae. Inner endite width 0.6 outer endite width, several fine setae distally, with two simple setae laterally. MxII (Fig. 21G), outer margin of mesial endite with several setae of varying length, distal margin with numerous long setae of varying length. Mesial endite almost as long as lateral endite. Lateral endite and middle endite each with three strong setae distally. Mxp (Fig. 21C), left and right Mxp connected by three retinacula. Epipodite smooth, triangular, slender, length 3.1 width, reaching mid of palpal article 3. Palpal article 2 width 0.9 length. Article 3 length 0.7 article 2 length, width 1.2 length, with seven robust sensory setae distally. Article 4 length 0.4 article 2 length, width half length. Article 5 length 0.4 article 2 length, width 0.2 length, with two slender setae terminally. Endite distal margin with some robust, dentate setae and several fine setae laterally. Basis length 1.5 width. PI (Fig. 20E) basis length 4 width. Ischium about half basis length, length 2.3 width, with one long simple seta dorsally. Merus length 0.6 ischium length, length 1.4 width, with one long simple seta distodorsally. Carpus length twice merus length, length 3 width, with numerous small setae, membranously embedded, and three long unequally bifid setae in between ventrally. Propodus length 0.6 carpus length, length 2.7 width, with one slender simple seta distodorsally, with numerous small setae, membranously embedded, and two robust unequally bifid setae in between ventrally, with one simple seta distoventrally. Dactylus length 0.6 propodus length, length 4 width, with two slender setae medially, with numerous small setae, membranously embedded ventally. Unguis length 0.6 dactylus length, with two long, slender setae underneath unguis. PII (Fig. 21H) basis length 4.4 width. Ischium length about half basis length, length 2.1 width, with two simple setae distodorsally. Merus length 0.8 ischium length, length 1.6 width, with three simple setae of varying length distodorsally, with one long simple seta distoventrally. Carpus length 2.1 merus length, length 4.2 width, with nine long slender simple setae (one broken off) ventrally. Propodus length 0.7 carpus length, length 4.3 width, with one simple seta distodorsally, with three simple setae ventrally. Dactylus length 0.4 propodus length, length 5.5 width, with three simple setae medially. Unguis length half dactylus length, with two slender setae underneath unguis. PIII (Fig. 21I) basis length 4 width. Ischium length 0.6 basis length, length 1.7 width, with two simple setae of varying length (one underneath) distoventrally. Merus length 0.7 ischium length, length 1.8 width, with two simple setae of varying length distodorsally, with one long simple seta distoventrally. Carpus length 2.3 merus length, length 4.7 width, with nine long simple setae ventrally. Propodus length 0.7 carpus length. Dactylus length 0.3 propodus length, length 4.5 width. Unguis length 0.6 dactylus length, with two slender setae underneath unguis. PIV (Fig. 21J) basis length 3.8 width. Ischium length 0.8 basis length, length 3.5 width. Merus length 0.6 ischium length, length 2.1 width. Carpus length 1.8 merus length, length 4.4 width, with seven long slender simple setae ventrally. Propodus length 0.9 carpus length, length 6.8 width, with two simple setae (underneath) dorsally, with two simple setae ventrally. Dactylus length 0.3 propodus length, length 3.5 width. Unguis damaged. PV (Fig. 21K) basis length 4.6 width. Ischium length 0.8 basis length, length 3.6 width. Merus length half ischium length, length 1.7 width, with two simple setae distodorsally. Carpus length 2.2 merus length, length 4.6 width, with one small simple seta distodorsally, with one slender simple seta medially, with five long, slender simple setae ventrally. Propodus length 0.7 carpus length, length 4.3 width, with nine long simple setae dorsally. Dactylus length 0.4 propodus length, length 6 width. Unguis length 0.7 dactylus length, ventral claw underneath. PVII (Fig. 21L) basis length 5.2 width, with four long setae simple setae ventrally, with one simple seta distoventrally. Ischium length 0.7 basis length, length 2.9 width. Merus length half ischium length, length 1.7 width, with two simple setae distodorsally. Carpus length twice merus length, length 4.2 width, with one simple seta (one broken off) distodorsally, with four simple setae (two long, two broken off) ventrally. Propodus length 0.8 carpus length, length 5 width, with seven long simple setae dorsally, with one simple seta (broken off) distoventrally. Dactylus length 0.4 propodus length, length 6 width. Unguis length 0.7 dactylus length, ventral claw underneath. Op (Fig. 20G) length 1.2 width, with a strong ventral spine, posteriorly bent. Lateral and posterior margins rounded, with several (≥ 21) simple setae, setal size 0.1 Plt length. PlpIII (Fig. 20H) protopodite length 0.9 width, length 0.4 endopodite length. Exopodite half endopodite length, length 1.7 width, tapering in width distally, with numerous short simple setae laterally, with one somewhat longer simple seta distally. Endopodite length 1.6 width, with three long plumose setae distally, distal margin strongly rounded. Urp (Fig. 20I), biramous, length 0.25 Plt length, not projecting beyond Plt posterior margin. Protopodite damaged proximally, with one simple seta distally. Exopodite length 7.3 width, with two simple setae (one broken off) terminally. Endopodite length 3.2 exopodite length, length 6.4 width, with one simple seta laterally, with 6 setae (three long simple, three broken off) terminally.
Remarks: Nannoniscus pedro is most similar to species that are characterized by a slender body (body length ≥ 4.5 pereonite 1 width) as well as those possessing a uropodal exopodite and a ventral opercular spine. The new species most closely resembles N. hilario, but can be differentiated by the following characters: Mxp endopodite reaching mid of palpal article 3 (vs. distal third of palpal article 2 in N. hilario); Md incisor teeth acute (vs. rounded); Urp endopodite length 3.2 exopodite length (vs. 6.3); Op posterior margin with ≥ 21 setae (vs. ≤ nine). Nannoniscus pedro is also similar to N. magdae, but differs from the latter species as follows: robust setae of anterolateral tergites of pereonite 2 present (vs. absent in N. magdae); Md incisor teeth acute (vs. rounded). The new species can be distinguished from N. menziesi by the following characters: molar process of left and right Md with five and four distal spines, respectively (vs. 12 and 16 spines, respectively, in N. menziesi); Urp endopodite length 3.2 exopodite length (vs. 5.4). Nannoniscus pedro differs from N. perunis as follows: Urp endopodite length 3.2 exopodite length (vs. 7.8). Finally, the new species can be distinguished from N. meteori by the following characters: Mxp epipodite length 3.1 width (vs. 6.4 in N. meteori); Urp exopodite length 7.3 width (vs. 3.0); Urp endopodite length 6.4 width (vs. 3.2); Op posterior margin with ≥ 21 (vs. ≤ 15).
NANNONISCUS BRENKEI KAISER, BRIX & JENNINGS,(FIG. 23)
Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: AF031C17-94B8-4274-A079-D113BC1423BC.
Type fixation: Holotype, preparatory female, ZMH K-55370, 2.5 mm, designated here.
Material examined: Holotype: preparatory female (NB12_Iso070), 2.5 mm, CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 33 (start: 11°51’44’’N, 117°3’10’’W, 4133 m; end: 11°51’54’’N, 117°3’8’’W, 4133 m), date: 07/04/2012, ZMH K-55370.
Paratypes: Preparatory female (Na03), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20 (start: 11°50’9’’N, 117°58’29’’W, 4093 m; end: 11°50’11’’N, 116°58’0’’W, 4093 m), date: 21/03/2015, ZMH K-55369; ovigerous female (Na24), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 24 (start: 11°51’19’’N, 117°1’30’’W, 4093 m; end: 11°51’31’’N, 116°58’0’’W, 4093 m), date: 22/03/2015, ZMH K-55371; male (?), badly damaged (MA14_Iso258), CCZ, equatorial NE Pacific, MANGAN 14 expedition, RV Kilo Moana EBS, station 21 (start: 11°49’44.52’’N, 117°00’27.06’’W, 4132 m; end: 11°49’56.76’’N, 116°59’40.62’’W, 4136 m), date: 10/05/2014, ZMH K-55368.
Etymology: The name of the new species (brenkei, Latin genitive, male) is dedicated to Nils Brenke, builder of the Brenke sledge (“Berta”), in recognition of his passion for deep-sea isopod taxonomy.
Distribution: The species is only known from four stations in the eastern German claim of the CCZ (type locality) between 4093 and 4136 m depth.
Diagnosis: Body slender, length about 5.0 × pereonite 1 width; Mxp epipodite reaching mid of palpal article 3; Mxp lateral margin with a fringe of setae; molar process of both Md each with only a few (≤ 5) distal spines; Md incisor teeth rounded; pereonite 2 anterolateral tergites each with robust seta; pereonite 7 without ventral spine; Op with a ventral posteriorly bent spine, posterior margin with numerous (≥ 14) long simple setae; Urp biramous, not projecting beyond Plt posterior margin; Urp endopodite length ≤ 5.8 exopodite length; Plp 3 exopodite 0.6 endopodite length, length 2.5 width, strongly tapering in width distally.
Description of holotype and paratype female: Habitus (Fig. 23A). Body length 5.5 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Fig. 23A), length 0.8 width. Anterior and posterior slightly rounded, lateral margins straight. Antennae inserting frontolaterally in a deep fold. Pereonites 2–4 decreasing in width, pereonites 4–7 of similar width. Pereonite 1 length 0.3 width. Pereonite 1 and 2 of similar width, pereonite 2 length 1.1 pereonite 1 length. Pereonite 3 length 1.3 pereonite 2 length. Pereonite 4 length 1.2 pereonite 2 length. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of pereonite 2 each tipped with a robust seta, anterolateral tergites of pereonites 3 and 4 each with a simple seta. Pereonite 5 length 1.5 pereonite 1 length, anterior margin straight. Pereonites 6 and 7 dorsomedially fused, anterior margin of pereonite 6 convex. Plt length 0.2 body length, length 1.4 width, width 0.8 pereonite 1 width, posterior margin strongly rounded; anterior margin slightly concave. Urp length 0.3 Plt length, not projecting beyond posterior margin. AI (Fig. 23B), terminal article broken off, inferred from holotype (in situ). Length 0.1 body length, with five articles. First article circular and broadest, length 2.1 width, with one small broom seta and one simple seta distally. Second article length 0.9 article 1 length, length 1.6 width, with three long broom setae and one seta (broken off) distally. Article 3 minute, length 0.2 article 1 length, half as long as wide. Article 4 length 0.3 article 2 length, with a long distal projection, with one long broom seta and two simple setae distally. Article 5 length 0.5 article 1 length, as long as wide. AII (Fig. 23B) broken off, only podomere articles 1–4 present; articles quadrangular of similar length and width. Md (Fig. 23C, D), palp of left mandible broken off, of right mandible well developed, consisting of three articles extending beyond distal end of incisor process. Palpal article 2 of rMd length 2.5 article 1 length, with one simple seta and two fringes of small setule laterally. Terminal article length about one-third article 2 length, tapering distally, with several small setae ventrally and three somewhat longer setae terminally. Incisor process of rMd with seven rounded teeth, incisor of lMd with five rounded teeth. Lacinia mobilis of lMd with three teeth. Spine row of rMd with nine robust spines of varying size and several slender setae in between; size increasing proximally. Spine row of lMd with nine robust spines, dentation decreasing, spine size increasing proximally. Molar of rMd and lMd triangular; molar of rMd with five, of lMd with four long, serrate spines distally. Mxp (Fig. 23E), left and right Mxp connected by three retinacula (one broken off). Epipodite smooth, triangular, slender, length 3.6 width, reaching mid of palpal article 3. Palpal article 2 as wide as long. Article 3 length 0.8 article 2 length, width 1.2 length, with four robust sensory setae and two simple setae distally. Article 4 length 0.3 article 2 length, width half length. Article 5 length 0.2 article 2 length, width about half length, with two slender setae terminally. Endite distal margin with some robust, dentate setae and several fine setae laterally. Basis length 0.7 width. PI (Fig. 23F) basis length 4 width, with one simple seta dorsally and two simple setae ventrally. Ischium length 0.6 basis length, length 2.2 width, with one small simple seta ventrally. Merus length 0.6 ischium length, length 1.2 width, with one long simple seta distodorsally and one long simple seta distoventrally. Carpus length twice merus length, length 2.6 width, with one long simple seta distodorsally, with numerous small setae, membranously embedded, and three long unequally bifid setae in between ventrally. Propodus length 0.7 carpus length, length 2.7 width, with one slender simple seta distodorsally, with numerous small setae, membranously embedded, and one small robust unequally bifid seta ventrally. Dactylus length 0.6 propodus length, length 3.1 width, with three slender setae medially, with numerous small setae, membranously embedded ventrally. Unguis length about half dactylus length, with one long, slender seta underneath unguis. Op (Fig. 23G) length 1.3 width, with a strong ventral spine, posteriorly bent. Lateral margins rounded, posterior margin almost straight, with several (≥ 14) simple setae, setal size 0.2 Plt length. PlpIII (Fig. 23H) protopodite length 1.7 width, length 0.7 endopodite length. Exopodite 0.6 endopodite length, length 2.5 width, strongly tapering in width distally, with numerous short simple setae laterally, with one somewhat longer simple seta distally. Endopodite length 2.1 width, with three long plumose setae distally, distal margin strongly rounded. Urp (Fig. 23I), biramous, length 0.3 Plt length, not projecting beyond Plt posterior margin. Protopodite length 1.7 width, with one simple seta distally (broken off). Exopodite length 3.0 width, with two simple setae terminally. Endopodite length 5.8 exopodite length, length 6.0 width, with six setae (three broom setae, three simple of varying length) terminally.
Remarks: The new species is characterized by a slender body, robust spines on the anterolateral tergites of pereonite 2, biramous uropods and a ventral opercular spine, and thus most closely resembles N. hilario, N. menziesi, N. meteori, N. pedro and N. perunis. Nannoniscus brenkei is most similar to N. hilario, but can be differentiated from the latter as follows: molar process of left and right mandible with ≤ five spines distally (vs. ≥ nine spines in N. hilario); Op distal margin with ≥ 14 simple setae (vs. ≤ nine). Nannoniscus brenkei also resembles N. meteori, but differs from the latter as follows: Mxp lateral margin with numerous small simple setae (vs. setae lacking in N. meteori); Urp endopodite length 5.8 exopodite length (vs. 3.9). The new species can be differentiated from N. menziesi by the following characters: Mxp lateral margin with numerous small simple setae (vs. setae lacking in N. menziesi); molar process of left and right mandible with ≤ 5 spines distally (vs. ≥ 12). Nannoniscus brenkei can be distinguished from N. pedro as follows: Md incisor teeth rounded (vs. acute in N. pedro); Mxp lateral margin with numerous small simple setae (vs. setae lacking); Urp endopodite length ≥ 5.8 exopodite length (vs. ≤ 3.2). Finally, the new species differs from N. perunis by the following features: body length ≥ 5.0 pereonite 1 width (vs. ≤ 4.7 in N. perunis); Urp endopodite length 5.8 exopodite length (vs. 7.8); pereonites 3–4 tergites each with an anterolateral seta (vs. setae lacking) (see also the identification key, Table 4).
(FIGS 15–19)
Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: 8BFC86F5-43FE-41AF-B49B-2793B2E7C3B8.
Type fixation: Holotype, ovigerous female, ZMH K-55354, 3.6 mm, designated here.
Material examined: Holotype: ovigerous female (Na27), 3.6 mm, CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 171 (start: 14°2’41’’N, 130°5’57’’W, 5024 m; end: 14°3’12’’N, 130°4’36’’W, 5017 m), date: 17/04/2015, ZMH K-55354.
Paratype: Preparatory female (Na18), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20 (start: 11°50’9’’N, 117°58’29’’W, 4093 m; end: 11°50’11’’N, 116°58’0’’W, 4093 m), date: 21/03/2015, ZMH K-55356; preparatory female (Na06), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 117 (start: 13°52’19’’N, 123°15’27’’W, 4498 m; end: 13°52’37’’N, 123°14’16’’W, 4521 m), date: 07/04/2015, ZMH K-55352; adult male (MA14_Iso272), CCZ, equatorial NE Pacific, KM14 expedition, RV Kilo Moana, EBS, station 38 (start: 11°47 52’’N, 117°30’31’’W, 4363 m; end: 11°48’3’’N, 117°29’45’’W, 4373 m), date: 13/05/2014, ZMH K-55350; preparatory female (Na42/Iso1120), APEI-6, equatorial NE Pacific, ABYSSLINE-2 expedition, RV Thomas G. Thompson, EBS, station APEI-6#1 (start: 19°27’52’’N, 120°1’31’’W, 4099 m; end: 120°0’58’’N, 120°0’58’’W, 4076 m), date: 20/03/2015, ZMH K-55355; preparatory female (NB12_Iso068), CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 33 (start: 11°51’44’’N, 117°3’10’’W, 4133 m; end: 11°51’54’’N, 117°3’8’’W, 4133 m), date: 07/04/2012, ZMH K-55353; preparatory female (MA14_Iso352), CCZ, equatorial NE Pacific, MA14 expedition, RV Kilo Moana, EBS, station 39 (start: 11°49’37’’N, 117°30’49’’W, 4361 m; end: 11°49’47’’N, 117°30’5’’W, 4343 m), date: 13/05/2014, ZMH K-55351; preparatory female (Na40/Iso1005), CCZ, equatorial NE Pacific, ABYSSLINE-2 expedition, RV Thomas G. Thompson, EBS, station S11 (start: 12°2’43.08’’N, 117°25’26’’W, 4223 m; end: 12°3’1.44’’N, 117°24’17’’W, 4235 m), date: 16/03/2015, ZMH K-55349; ovigerous female (MA13_ Iso453), CCZ, equatorial NE Pacific, MA13 expedition, RV Kilo Moana, EBS, station 90 (start: 11°49.718’N, 117°30.278’W, 4340 m; end: 11°49.906’N, 117°29.395’W, 4357 m), date: 03/05/2013, ZMH K-55348.
Etymology: The new species (menoti, Latin genitive, masculine) is named after Lenaick Menot, leader of the French party of the BIONOD expedition, for joint actions sieving and sorting the mud.
Distribution: This species has a wide distribution across the CCZ, being obtained from the eastern German, OMS, GSR and French (type locality) licence areas, as well as APEI-6 between 4076 and 5024 m depth.
Diagnosis: Body slender, length about 5.1 × pereonite 1 width; Mxp lateral margin with numerous small setae; Mxp epipodite reaching mid of palpal article 3; molar process of left Md with ≥ ten distal spines; Md incisor teeth rounded; pereonite 2 anterolateral tergites each with robust seta; pereonite 2 anterolateral tergites each with robust seta; pereonite 7 without ventral spine; Op with a ventral posteriorly bent spine, posterior margin with numerous (≥ 15) short simple setae; Urp uniramous, not projecting beyond Plt posterior margin; male PlpI without hook-like projections distally.
Description of holotype and paratype female: Habitus (Figs 15D, 18), pereonites 2 and 3 damaged. Body length 5.1 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Figs 15D, 18D, E), length 0.9 width. Anterior and lateral margins straight, posterior m a r g i n s l i g h t l y r o u n d e d. A n t e n n a e i n s e r t i n g frontolaterally in a deep fold. Pereonite 2 widest, pereonites 2–7 decreasing in width. Pereonite 1 width 0.8 pereonite 2 width, length 0.4 width. Pereonites 2 and 3 of similar length and width, length approximately 1.3 pereonite 1 length. Pereonite 4 longest, length 1.7 pereonite 1 length. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of pereonite 2 each tipped with a robust seta, pereonites 3–4 each with a slender seta. Pereonite 5 width 0.9 pereonite 1 width, length 1.6 pereonite 1 length; pereonite 5 anterior margin slightly convex. Pereonites 6–7 dorsomedially fused, pereonite 6 anterior margin convex. Plt length 0.2 body length, length 1.4 width; width 0.9 pereonite 1 width, posterior margin strongly rounded; anterior margin straight. Urp length 0.2 Plt length, not projecting beyond posterior margin. AI described in situ from CLSM (Fig. 18A, E), from CLSM. Length 0.1 body length, with five articles. First article broadest, length twice width, with one broom seta distally. Second article as long as article 1, length 2.4 width, with two broom setae distally. Article 3 minute, length 0.2 article 1 length, as long as wide. Article 4 length 0.3 article 1 length, with a long distal projection reaching mid of article 5. Article 5 length 0.7 article 2 length, length 1.8 width. AII (Fig. 15A) length 0.4 body length, with six podomere and 11 flagellar articles. Podomere article 1 broken off, described from CLSM (Fig. 18A). Articles 1–4 short; article 3 with three simple setae and one small robust spine distally, article 4 with one simple seta distally. Article 5 length 1.5 articles 1–4 length, length approximately 5.8 width, with six simple setae laterally. Article 6 longest, length 1.1 article 5 length, length 6 width, with three simple setae laterally, with four broom setae of varying size and two long simple setae distally. Flagellar article 1 longest, conjoint with one setal position (fusion of 2 articles), length half podomere article 6 length, length 4.5 width, with two simple setae laterally. Flagellar articles 3–11 decreasing in length and width distally; each article with 1–3 simple setae distally. Article 11 with six long slender setae terminally. Md (Fig. 15B, C), palp of left and right Md broken off. Incisor process of rMd and lMd with four rounded teeth each. Lacinia mobilis of lMd with three teeth. Spine row of rMd with 12 robust spines, dentation decreasing proximally. Spine row of lMd with ten robust spines and several slender setae in between, dentation decreasing, seta size increasing proximally. Molar of lMd triangular, with ten serrate spines of varying size distally. MxII (Fig. 15E), outer margin of mesial endite with several setae of varying length, distal margin with numerous long setae of varying length. Mesial endite as long as lateral endite. Lateral endite and middle endite each with three strong setae distally. Mxp (Fig. 15F), left and right Mxp connected by three retinacula. Epipodite smooth, triangular, slender, length 3.1 width, reaching mid of palpal article 3. Palpal article 1 short, with several small setae laterally. Article 2 length 2.4 article 1 length, width 0.9 length, with several small setae laterally. Article 3 length 1.1 article 1 length, width 1.6 length, with four robust sensory setae (one broken off) and one somewhat longer simple seta distally. Article 4 length 1.4 article 1 length, width 0.3 length, with a distal projection reaching mid of article 5, with two slender setae distally. Article 5 length 0.8 article 1 length, width 0.3 length, with three slender setae of varying size terminally. Endite distal margin with some robust, dentate setae and several fine setae laterally. Basis quadrangular, length 0.9 width. PI (Fig. 16B) basis length 3.4 width, one small simple seta ventrally. Ischium 0.6 basis length, length 2.6 width, with one long simple seta distodorsally. Merus length 0.6 ischium length, length 1.4 width, with two long simple setae distodorsally. Carpus length 2.2 merus length, length 3.7 width, with one simple seta distodorsally, with five unequally bifid setae and numerous small setae ventrally. Propodus length 0.6 carpus length, length 3 width, with one simple seta dorsally, with numerous small setae, membranously embedded, ventrally, with one simple seta distoventrally. Dactylus length about half propodus length, length 3.7 width, with three slender setae medially. Unguis length half dactylus length, with two long, slender setae underneath unguis. PII (Fig. 16C) basis length 3.8 width. Ischium length about half basis length, length 2.3 width, with one long simple seta distodorsally. Merus length 0.7 ischium length, length 1.5 width, with two simple setae of varying length distodorsally, with one simple seta ventrally, and one simple seta distoventrally. Carpus length 2.6 merus length, length 4.3 width, with seven unequally bifid setae ventrally increasing in size distally. Propodus length 0.6 carpus length, length 4 width, with one long simple seta distodorsally, with numerous small setae, membranously embedded, and two small unequally bifid setae ventrally. Dactylus length 0.4 propodus length, length 3.3 width, with numerous small setae, membranously embedded ventrally. Unguis length half dactylus length, with two long, slender setae underneath unguis. PIII (Fig. 16D) basis length 4.7 width, with one long robust simple seta distoventrally. Ischium 0.4 basis length, length 2.1 width, with one simple seta distodorsally. Merus length 0.9 ischium length, length 1.8 width, with one simple seta distodorsally, with one simple seta (broken off) distoventrally. Carpus length 2.5 merus length, length 5.4 width, with eight robust setae (three unequally bifid setae, five simple) ventrally. Propodus length 0.6 carpus length, length 4.8 width, with six long simple setae (four broken off) dorsally, with numerous small setae, membranously embedded, and two small unequally bifid setae ventrally. Dactylus length 0.4 propodus length, length 6 width, with two simple setae medially. Unguis length 0.6 dactylus length, with two long, slender setae underneath unguis. PIV (Fig. 16E) basis length 5.5 width, with three simple setae dorsally, with three simple setae ventrally. Ischium length half basis length, length 2.9 width, with one simple seta distodorsally, with one simple seta ventrally. Merus length 0.6 ischium length, length twice width, with one long simple seta distodorsally, with one long simple seta distoventrally. Carpus length 2.5 merus length, length 6.4 width, with five simple setae (underneath) dorsally, with nine slender simple setae ventrally, increasing in size distally. Propodus length 0.6 carpus length, length 4.8 width, with six simple setae (four broken off) dorsally, with numerous small setae, membranously embedded, and four small unequally bifid setae ventrally. Dactylus length 0.4 propodus length, length 6 width, with two simple setae medially, with numerous small setae ventrally. Unguis length 0.3 dactylus length, with two slender setae underneath unguis. PV (Fig. 16F) basis length 4.5 width, one long simple seta distodorsally. Ischium length 0.8 basis length, length 3.6 width, with two long simple setae dorsally. Merus length half ischium length, length 1.8 width, with two simple setae of varying size distodorsally, with one small simple seta distoventrally. Carpus length 2.1 merus length, length 3.4 width, with six long simple setae (one broken off) ventrally. Propodus length 0.7 carpus length, length 2.9 width, with seven long simple setae (underneath) dorsally, with four long simple setae ventrally. Dactylus length half propodus length, length 3.5 width. Unguis length 0.7 dactylus length, with two setae of varying size underneath unguis. PVI (Fig. 16G) basis length 3.1 width, with one simple seta distoventrally. Ischium as long as basis, length 2.7 width, with one small simple seta ventrally. Merus length 0.4 ischium length, length 1.5 width, with two simple setae (one broken off) distodorsally, with one small simple seta ventrally. Carpus length 2.4 merus length, length 3.8 width, with one slender setae distodorsally, with three long simple setae ventrally. Propodus length 0.8 carpus length, length 5 width, with eight long setae dorsally, with two long setae distoventrally. Dactylus length half propodus length, length 5.3 width. Unguis length 0.8 dactylus length, with two slender seta underneath unguis. PVII (Fig. 16H) basis length 4.5 width. Ischium damaged, length 0.6 basis length, length 2.4 width. Merus length half ischium length, length 1.3 width. Carpus length 2.4 merus length, length 3.9 width, with eight long slender simple setae dorsally, with three simple setae dorsally, with one simple seta distodorsally, with three setae (two simple, one unequally bifid) of varying size ventrally. Propodus length 0.7 carpus length, length 4 width, with five long simple setae dorsally, with one simple seta ventrally, with one robust simple seta distoventrally. Dactylus length half propodus length, length 3.1 width. Unguis length 0.8 dactylus length, with two slender setae underneath unguis. Op (Fig. 15G), drawn in situ. Length 1.4 width, with a strong ventral spine, posteriorly bent. Lateral and posterior margins, with several (≥ 15) simple setae, setal size 0.1 Plt length. PlpIII (Fig. 15H) protopodite length 0.9 width, length 0.3 endopodite length. Exopodite half endopodite length, length 1.8 width, tapering in width distally, with numerous short simple setae laterally and one somewhat longer seta distally. Endopodite length 1.8 width, with two long plumose setae distally, distal margin rounded. PlpIV (Fig. 15I) protopodite rectangular, length 0.6 width, length 0.2 endopodite length. Exopodite slender, length 0.7 endopodite length, length 7.2 width, with several thin setules laterally (outer margin) and one long robust plumose seta distally. Endopodite length 2.6 width, distal end tapering in an acute angle. PlpV (Fig. 15J) small oval lobe, without setation, about as long as pleopod 4 endopodite. Length 2.2 proximal width, width tapering towards distal end. Urp (Fig. 15K) uniramous, length 0.2 Plt length, not projecting beyond Plt posterior margin. Protopodite oval, length 1.4 width, with five simple setae of varying length laterally. Endopodite length 1.6 protopodite length, length 5.3 width, with one broom seta laterally, with three broom setae and four simple setae (three broken off) terminally.
Description of male paratype: Habitus (Figs 17A, 19). Body length 5.7 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Figs 17A, 19D, E), length 1.1 width. Anterior and lateral margins rounded, posterior margin almost straight. Antennae inserting frontolaterally in a deep fold. Pereonites 2–5 decreasing in width. Pereonite 1 length 0.3 width. Pereonite 2 widest, width 1.1 pereonite 1 width, length 2.1 pereonite 1 length. Pereonites 2–3 of similar length. Pereonites 4–7 of similar length, pereonite 4 length 1.9 pereonite 1 length. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of perenonite 2 each tipped with a robust seta, anterolateral tergites of pereonites 3–4 each with simple seta. Pereonites 5–7 of similar width, width 0.8 pereonite 1 width. Pereonite 5 anterior margin straight. Pereonites 6–7 dorsomedially fused, pereonite 6 anterior margin straight. Plt 0.2 body length, length 1.4 width, width 0.7 pereonite 1 width; posterior margin strongly rounded, anterior margin slightly concave. Anus (Fig. 19B, F) covered by anus valves laterally. Urp inserting closely to the anus valves, length 0.2 Plt length, not projecting beyond posterior margin. PlpI (Figs 17B, 19B, F), length 3.2 proximal width. Distal projection width 0.4 proximal width, lateral margins slightly concave. Lateral lobes rounded, with five small setae inserting distally from each lateral lobe. Distal margins strongly rounded, with four simple setae of varying length each. PlpII (Fig. 17C), sympod length 2.5 width, outer margin rounded, with six long slender simple setae distally, with numerous small setae laterally; inner margin straight. Endopod inserting 0.3 from distal tip of sympod. Stylet length 0.6 sympod length, slightly curved, distal end not extending beyond distal tip of sympod. Exopod short and rounded, inserting 0.1 from distal tip of sympod. PlpIII (Fig. 17D), protopodite length 1.3 width, length half endopodite length. Exopodite half endopodite length, length 1.3 width, tapering in width distally, with numerous short simple setae laterally and one somewhat longer seta distally. Endopodite length 1.6 width, with three long plumose setae distally, distal margin rounded. PlpIV (Fig. 17E), protopodite rectangular, length 0.6 width, length 0.3 endopodite length. Exopodite slender, length 0.7 endopodite length, length 6.8 width, with several thin setules laterally (outer margin) and one long robust plumose seta distally. Endopodite length 1.8 width, distal margin rounded.
Remarks: The new species is distinct from most other species in the genus by possessing uniramous uropods. Besides N. menoti, only N. ovatus lacks a uropodal exopodite. The new species can be differentiated from N. ovatus as follows: body length 5.1 pereonite 1 width in female (vs. 4.7 in N. ovatus); Op posterior margin with ≥ 15 setae (vs. ≤ 9); Mxp lateral margin with numerous small setae (vs. Mxp lateral margin lacking setae); male PlpI without hook-like projections distally (vs. 3).
NANNONISCUS PEDRO KAISER, BRIX & KIHARA,(FIGS 20–22)
Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: 820608B2-7BAA-43B1-8B40-3A5561937B8B.
Type fixation: Holotype, preparatory female, ZMH K-55358, 3.4 mm, designated here.
Material examined: Holotype: preparatory female (Na08), 3.4 mm, CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 133 (start: 13°50‘45’’N, 123°15’39’’W, 4516 m; end: 13°51’8’’N, 123°14’8’’W, 4427 m), date: 10/04/2015, ZMH K-55358.
Paratypes: Ovigerous female (Na11), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 171 (start: 14°2’41’’N, 130°5’57’’W, 5024 m; end: 14°3’12’’N, 130°4’36’’W, 5017 m), date: 17/04/2015, ZMH K-55362; preparatory female (Na04), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20 (start: 11°50’9’’N, 117°58’29’’W, 4093 m; end: 11°50’11’’N, 116°58’0’’W, 4093 m), date: 21/03/2015, ZMH K-55361; preparatory female (Na05), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20, ZMH K-55365; preparatory female (Na22), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 24 (start: 11°51’19’’N, 117°1’30’’W, 4093 m; end: 11°51’31’’N, 116°58’0’’W, 4093 m), date: 22/03/2015, ZMH K-55363; preparatory female (NB12_Iso_290), CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 43 (start: 11°48’12’’N, 117°32’3’’W, 4358 m; end: 11°48’20’’N, 117°31’57’’W, 4358 m), date: 09/04/2012, ZMH K-55360; preparatory female (NB12_Iso_330), CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 43, ZMH K-55364; preparatory female (MA13_Iso593), CCZ, equatorial NE Pacific, MA13 expedition, RV Kilo Moana, EBS, station 90 (start: 11°49.718’N, 117°30.278’W, 4340 m; end: 11°49.906’N, 117°29.395’W, 4357 m), date: 03/05/2013, ZMH K-55359; preparatory female (MA13_ Iso049), CCZ, equatorial NE Pacific, MA13 expedition, RV Kilo Moana, EBS, station 07 (start: 11°51.503’N, 117°01.205’W, 4131 m; end: 11°51.756’N, 117°00.171’W, 4121 m), date: 12/04/2013, ZMH K-55357; female, badly damaged (MA14_Iso319), CCZ, equatorial NE Pacific, MA14 expedition, RV Kilo Moana, EBS, station 39 (start: 11°49’37’’N, 117°30’49’’W, 4361 m; end: 11°49’47’’N, 117°30’5’’W, 4343 m), date: 13/05/2014, ZMH K-55367; male, badly damaged (MA14_Iso242), CCZ, equatorial NE Pacific, MA14 expedition, RV Kilo Moana, EBS, station 39, date: 13/05/2014, ZMH K-55366.
Etymology: The name is a noun in apposition, and dedicated to Pedro Martinez Arbizu, Principal Investigator of the JPIO EcoResponse expedition, for his drive and commitment to the exploration of the abyssal manganese nodule fauna.
Distribution: The species has a broad distribution across the CCZ, being collected from the eastern German, GSR (type locality) and French licence areas between 4093 and 5024 m depth.
Diagnosis: Body slender, length about 5.5 × pereonite 1 width; Mxp epipodite reaching mid of palpal article 3; Mxp lateral margin lacking fringe of setae; molar process of both Md each with only a few (≤ 5) distal spines; Md incisor teeth acute; pereonite 2 anterolateral tergites each with robust seta; pereonite 7 without ventral spine; Op with a ventral posteriorly bent spine, posterior margin with numerous (≥ 21) long simple setae; Urp biramous, not projecting beyond Plt posterior margin; Urp endopodite length ≥ 3.2 exopodite length.
Description of holotype and paratype female: Habitus (Figs 20A, B, 22), body length 5.5 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Figs 20A, 22D–E), length 0.7 width. Anterior and posterior margins straight, lateral margin slightly rounded. Antennae inserting frontolaterally in a deep fold. Body abruptly flattening from pereonite 4 to 5. Pereonites 2–4 decreasing in width, pereonites 4–7 of similar width. Pereonite 1 length 0.3 width. Pereonite 1 and 2 of similar width, pereonite 2 length 1.7 pereonite 1 length. Pereonites 3 and 4 of similar length, length 1.2 pereonite 2. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of pereonite 2 each tipped with a robust seta, anterolateral tergites of pereonites 3 and 4 each with a simple seta. Pereonite 5 length 1.8 pereonite 1 length, anterior margin straight. Pereonites 6 and 7 dorsomedially fused, anterior margin of pereonite 6 convex. Plt length 0.2 body length, length 1.2 width, width 0.9 pereonite 1 width, posterior margin strongly rounded; anterior margin concave. Urp length 0.3 Plt length, not projecting beyond posterior margin. AI (Fig. 20C), terminal article broken off, inferred from CLSM (Fig. 22A, E). Length 0.1 body length, with five articles. First article circular and broadest, length 2.3 width. Second article length 0.7 article 1 length, length 1.8 width, with two simple setae distally. Article 3 minute, length 0.1 article 1 length, as long as wide. Article 4 length 0.1 article 2 length, with a long distal projection reaching mid of article 5, with one simple seta distally. Article 5 length 0.9 article 2 length, length 1.2 width, with one aestetasc terminally. AII (Fig. 20D) length 0.4 body length, with six podomere and nine flagellar articles. Podomere articles 1–4 short. Article 5 longest, length 1.2 articles 1–4 length, length 5.4 width. Article 6 length 0.9 article 5 length, length 5.6 width. Flagellar article 1 longest, conjoint (fusion of three articles), length 0.6 podomere article 6 length, length 4.8 width. Flagellar articles 2–4 of similar length, length 0.2 flagellar article 1 length. Flagellar 5 article longest, length 0.3 flagellar article 1 length. Flagellar articles 1–9 decreasing in width distally, each article with 0–3 simple setae distally. Article 9 with seven long slender setae terminally. Md (Fig. 21D, E), palp of right mandible damaged, of left mandible well developed, consisting of three articles almost reaching mid of incisor. Palpal article 2 of lMd length 1.2 article 1 length, with two simple setae laterally. Terminal article length about half article 2 length, tapering distally, with several small setae ventrally and two somewhat longer setae terminally. Incisor process of rMd with three acute teeth, incisor of lMd with six acute teeth and one subdistal tooth. Lacinia mobilis of lMd with three teeth. Spine row of rMd with ten robust spines of varying size and several slender setae in between; dentation decreasing proximally. Spine row of lMd with eight robust spines and several slender setae in between, dentation decreasing, spine size increasing proximally. Molar of rMd and lMd triangular; molar of rMd with four, of lMd with five long, serrate spines distally. MxI (Fig. 21F) outer endite with 17 robust spine-like setae distally. Outer margin with several slender setae. Inner endite width 0.6 outer endite width, several fine setae distally, with two simple setae laterally. MxII (Fig. 21G), outer margin of mesial endite with several setae of varying length, distal margin with numerous long setae of varying length. Mesial endite almost as long as lateral endite. Lateral endite and middle endite each with three strong setae distally. Mxp (Fig. 21C), left and right Mxp connected by three retinacula. Epipodite smooth, triangular, slender, length 3.1 width, reaching mid of palpal article 3. Palpal article 2 width 0.9 length. Article 3 length 0.7 article 2 length, width 1.2 length, with seven robust sensory setae distally. Article 4 length 0.4 article 2 length, width half length. Article 5 length 0.4 article 2 length, width 0.2 length, with two slender setae terminally. Endite distal margin with some robust, dentate setae and several fine setae laterally. Basis length 1.5 width. PI (Fig. 20E) basis length 4 width. Ischium about half basis length, length 2.3 width, with one long simple seta dorsally. Merus length 0.6 ischium length, length 1.4 width, with one long simple seta distodorsally. Carpus length twice merus length, length 3 width, with numerous small setae, membranously embedded, and three long unequally bifid setae in between ventrally. Propodus length 0.6 carpus length, length 2.7 width, with one slender simple seta distodorsally, with numerous small setae, membranously embedded, and two robust unequally bifid setae in between ventrally, with one simple seta distoventrally. Dactylus length 0.6 propodus length, length 4 width, with two slender setae medially, with numerous small setae, membranously embedded ventally. Unguis length 0.6 dactylus length, with two long, slender setae underneath unguis. PII (Fig. 21H) basis length 4.4 width. Ischium length about half basis length, length 2.1 width, with two simple setae distodorsally. Merus length 0.8 ischium length, length 1.6 width, with three simple setae of varying length distodorsally, with one long simple seta distoventrally. Carpus length 2.1 merus length, length 4.2 width, with nine long slender simple setae (one broken off) ventrally. Propodus length 0.7 carpus length, length 4.3 width, with one simple seta distodorsally, with three simple setae ventrally. Dactylus length 0.4 propodus length, length 5.5 width, with three simple setae medially. Unguis length half dactylus length, with two slender setae underneath unguis. PIII (Fig. 21I) basis length 4 width. Ischium length 0.6 basis length, length 1.7 width, with two simple setae of varying length (one underneath) distoventrally. Merus length 0.7 ischium length, length 1.8 width, with two simple setae of varying length distodorsally, with one long simple seta distoventrally. Carpus length 2.3 merus length, length 4.7 width, with nine long simple setae ventrally. Propodus length 0.7 carpus length. Dactylus length 0.3 propodus length, length 4.5 width. Unguis length 0.6 dactylus length, with two slender setae underneath unguis. PIV (Fig. 21J) basis length 3.8 width. Ischium length 0.8 basis length, length 3.5 width. Merus length 0.6 ischium length, length 2.1 width. Carpus length 1.8 merus length, length 4.4 width, with seven long slender simple setae ventrally. Propodus length 0.9 carpus length, length 6.8 width, with two simple setae (underneath) dorsally, with two simple setae ventrally. Dactylus length 0.3 propodus length, length 3.5 width. Unguis damaged. PV (Fig. 21K) basis length 4.6 width. Ischium length 0.8 basis length, length 3.6 width. Merus length half ischium length, length 1.7 width, with two simple setae distodorsally. Carpus length 2.2 merus length, length 4.6 width, with one small simple seta distodorsally, with one slender simple seta medially, with five long, slender simple setae ventrally. Propodus length 0.7 carpus length, length 4.3 width, with nine long simple setae dorsally. Dactylus length 0.4 propodus length, length 6 width. Unguis length 0.7 dactylus length, ventral claw underneath. PVII (Fig. 21L) basis length 5.2 width, with four long setae simple setae ventrally, with one simple seta distoventrally. Ischium length 0.7 basis length, length 2.9 width. Merus length half ischium length, length 1.7 width, with two simple setae distodorsally. Carpus length twice merus length, length 4.2 width, with one simple seta (one broken off) distodorsally, with four simple setae (two long, two broken off) ventrally. Propodus length 0.8 carpus length, length 5 width, with seven long simple setae dorsally, with one simple seta (broken off) distoventrally. Dactylus length 0.4 propodus length, length 6 width. Unguis length 0.7 dactylus length, ventral claw underneath. Op (Fig. 20G) length 1.2 width, with a strong ventral spine, posteriorly bent. Lateral and posterior margins rounded, with several (≥ 21) simple setae, setal size 0.1 Plt length. PlpIII (Fig. 20H) protopodite length 0.9 width, length 0.4 endopodite length. Exopodite half endopodite length, length 1.7 width, tapering in width distally, with numerous short simple setae laterally, with one somewhat longer simple seta distally. Endopodite length 1.6 width, with three long plumose setae distally, distal margin strongly rounded. Urp (Fig. 20I), biramous, length 0.25 Plt length, not projecting beyond Plt posterior margin. Protopodite damaged proximally, with one simple seta distally. Exopodite length 7.3 width, with two simple setae (one broken off) terminally. Endopodite length 3.2 exopodite length, length 6.4 width, with one simple seta laterally, with 6 setae (three long simple, three broken off) terminally.
Remarks: Nannoniscus pedro is most similar to species that are characterized by a slender body (body length ≥ 4.5 pereonite 1 width) as well as those possessing a uropodal exopodite and a ventral opercular spine. The new species most closely resembles N. hilario, but can be differentiated by the following characters: Mxp endopodite reaching mid of palpal article 3 (vs. distal third of palpal article 2 in N. hilario); Md incisor teeth acute (vs. rounded); Urp endopodite length 3.2 exopodite length (vs. 6.3); Op posterior margin with ≥ 21 setae (vs. ≤ nine). Nannoniscus pedro is also similar to N. magdae, but differs from the latter species as follows: robust setae of anterolateral tergites of pereonite 2 present (vs. absent in N. magdae); Md incisor teeth acute (vs. rounded). The new species can be distinguished from N. menziesi by the following characters: molar process of left and right Md with five and four distal spines, respectively (vs. 12 and 16 spines, respectively, in N. menziesi); Urp endopodite length 3.2 exopodite length (vs. 5.4). Nannoniscus pedro differs from N. perunis as follows: Urp endopodite length 3.2 exopodite length (vs. 7.8). Finally, the new species can be distinguished from N. meteori by the following characters: Mxp epipodite length 3.1 width (vs. 6.4 in N. meteori); Urp exopodite length 7.3 width (vs. 3.0); Urp endopodite length 6.4 width (vs. 3.2); Op posterior margin with ≥ 21 (vs. ≤ 15).
NANNONISCUS BRENKEI KAISER, BRIX & JENNINGS,(FIG. 23)
Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: AF031C17-94B8-4274-A079-D113BC1423BC.
Type fixation: Holotype, preparatory female, ZMH K-55370, 2.5 mm, designated here.
Material examined: Holotype: preparatory female (NB12_Iso070), 2.5 mm, CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 33 (start: 11°51’44’’N, 117°3’10’’W, 4133 m; end: 11°51’54’’N, 117°3’8’’W, 4133 m), date: 07/04/2012, ZMH K-55370.
Paratypes: Preparatory female (Na03), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20 (start: 11°50’9’’N, 117°58’29’’W, 4093 m; end: 11°50’11’’N, 116°58’0’’W, 4093 m), date: 21/03/2015, ZMH K-55369; ovigerous female (Na24), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 24 (start: 11°51’19’’N, 117°1’30’’W, 4093 m; end: 11°51’31’’N, 116°58’0’’W, 4093 m), date: 22/03/2015, ZMH K-55371; male (?), badly damaged (MA14_Iso258), CCZ, equatorial NE Pacific, MANGAN 14 expedition, RV Kilo Moana EBS, station 21 (start: 11°49’44.52’’N, 117°00’27.06’’W, 4132 m; end: 11°49’56.76’’N, 116°59’40.62’’W, 4136 m), date: 10/05/2014, ZMH K-55368.
Etymology: The name of the new species (brenkei, Latin genitive, male) is dedicated to Nils Brenke, builder of the Brenke sledge (“Berta”), in recognition of his passion for deep-sea isopod taxonomy.
Distribution: The species is only known from four stations in the eastern German claim of the CCZ (type locality) between 4093 and 4136 m depth.
Diagnosis: Body slender, length about 5.0 × pereonite 1 width; Mxp epipodite reaching mid of palpal article 3; Mxp lateral margin with a fringe of setae; molar process of both Md each with only a few (≤ 5) distal spines; Md incisor teeth rounded; pereonite 2 anterolateral tergites each with robust seta; pereonite 7 without ventral spine; Op with a ventral posteriorly bent spine, posterior margin with numerous (≥ 14) long simple setae; Urp biramous, not projecting beyond Plt posterior margin; Urp endopodite length ≤ 5.8 exopodite length; Plp 3 exopodite 0.6 endopodite length, length 2.5 width, strongly tapering in width distally.
Description of holotype and paratype female: Habitus (Fig. 23A). Body length 5.5 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Fig. 23A), length 0.8 width. Anterior and posterior slightly rounded, lateral margins straight. Antennae inserting frontolaterally in a deep fold. Pereonites 2–4 decreasing in width, pereonites 4–7 of similar width. Pereonite 1 length 0.3 width. Pereonite 1 and 2 of similar width, pereonite 2 length 1.1 pereonite 1 length. Pereonite 3 length 1.3 pereonite 2 length. Pereonite 4 length 1.2 pereonite 2 length. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of pereonite 2 each tipped with a robust seta, anterolateral tergites of pereonites 3 and 4 each with a simple seta. Pereonite 5 length 1.5 pereonite 1 length, anterior margin straight. Pereonites 6 and 7 dorsomedially fused, anterior margin of pereonite 6 convex. Plt length 0.2 body length, length 1.4 width, width 0.8 pereonite 1 width, posterior margin strongly rounded; anterior margin slightly concave. Urp length 0.3 Plt length, not projecting beyond posterior margin. AI (Fig. 23B), terminal article broken off, inferred from holotype (in situ). Length 0.1 body length, with five articles. First article circular and broadest, length 2.1 width, with one small broom seta and one simple seta distally. Second article length 0.9 article 1 length, length 1.6 width, with three long broom setae and one seta (broken off) distally. Article 3 minute, length 0.2 article 1 length, half as long as wide. Article 4 length 0.3 article 2 length, with a long distal projection, with one long broom seta and two simple setae distally. Article 5 length 0.5 article 1 length, as long as wide. AII (Fig. 23B) broken off, only podomere articles 1–4 present; articles quadrangular of similar length and width. Md (Fig. 23C, D), palp of left mandible broken off, of right mandible well developed, consisting of three articles extending beyond distal end of incisor process. Palpal article 2 of rMd length 2.5 article 1 length, with one simple seta and two fringes of small setule laterally. Terminal article length about one-third article 2 length, tapering distally, with several small setae ventrally and three somewhat longer setae terminally. Incisor process of rMd with seven rounded teeth, incisor of lMd with five rounded teeth. Lacinia mobilis of lMd with three teeth. Spine row of rMd with nine robust spines of varying size and several slender setae in between; size increasing proximally. Spine row of lMd with nine robust spines, dentation decreasing, spine size increasing proximally. Molar of rMd and lMd triangular; molar of rMd with five, of lMd with four long, serrate spines distally. Mxp (Fig. 23E), left and right Mxp connected by three retinacula (one broken off). Epipodite smooth, triangular, slender, length 3.6 width, reaching mid of palpal article 3. Palpal article 2 as wide as long. Article 3 length 0.8 article 2 length, width 1.2 length, with four robust sensory setae and two simple setae distally. Article 4 length 0.3 article 2 length, width half length. Article 5 length 0.2 article 2 length, width about half length, with two slender setae terminally. Endite distal margin with some robust, dentate setae and several fine setae laterally. Basis length 0.7 width. PI (Fig. 23F) basis length 4 width, with one simple seta dorsally and two simple setae ventrally. Ischium length 0.6 basis length, length 2.2 width, with one small simple seta ventrally. Merus length 0.6 ischium length, length 1.2 width, with one long simple seta distodorsally and one long simple seta distoventrally. Carpus length twice merus length, length 2.6 width, with one long simple seta distodorsally, with numerous small setae, membranously embedded, and three long unequally bifid setae in between ventrally. Propodus length 0.7 carpus length, length 2.7 width, with one slender simple seta distodorsally, with numerous small setae, membranously embedded, and one small robust unequally bifid seta ventrally. Dactylus length 0.6 propodus length, length 3.1 width, with three slender setae medially, with numerous small setae, membranously embedded ventrally. Unguis length about half dactylus length, with one long, slender seta underneath unguis. Op (Fig. 23G) length 1.3 width, with a strong ventral spine, posteriorly bent. Lateral margins rounded, posterior margin almost straight, with several (≥ 14) simple setae, setal size 0.2 Plt length. PlpIII (Fig. 23H) protopodite length 1.7 width, length 0.7 endopodite length. Exopodite 0.6 endopodite length, length 2.5 width, strongly tapering in width distally, with numerous short simple setae laterally, with one somewhat longer simple seta distally. Endopodite length 2.1 width, with three long plumose setae distally, distal margin strongly rounded. Urp (Fig. 23I), biramous, length 0.3 Plt length, not projecting beyond Plt posterior margin. Protopodite length 1.7 width, with one simple seta distally (broken off). Exopodite length 3.0 width, with two simple setae terminally. Endopodite length 5.8 exopodite length, length 6.0 width, with six setae (three broom setae, three simple of varying length) terminally.
Remarks: The new species is characterized by a slender body, robust spines on the anterolateral tergites of pereonite 2, biramous uropods and a ventral opercular spine, and thus most closely resembles N. hilario, N. menziesi, N. meteori, N. pedro and N. perunis. Nannoniscus brenkei is most similar to N. hilario, but can be differentiated from the latter as follows: molar process of left and right mandible with ≤ five spines distally (vs. ≥ nine spines in N. hilario); Op distal margin with ≥ 14 simple setae (vs. ≤ nine). Nannoniscus brenkei also resembles N. meteori, but differs from the latter as follows: Mxp lateral margin with numerous small simple setae (vs. setae lacking in N. meteori); Urp endopodite length 5.8 exopodite length (vs. 3.9). The new species can be differentiated from N. menziesi by the following characters: Mxp lateral margin with numerous small simple setae (vs. setae lacking in N. menziesi); molar process of left and right mandible with ≤ 5 spines distally (vs. ≥ 12). Nannoniscus brenkei can be distinguished from N. pedro as follows: Md incisor teeth rounded (vs. acute in N. pedro); Mxp lateral margin with numerous small simple setae (vs. setae lacking); Urp endopodite length ≥ 5.8 exopodite length (vs. ≤ 3.2). Finally, the new species differs from N. perunis by the following features: body length ≥ 5.0 pereonite 1 width (vs. ≤ 4.7 in N. perunis); Urp endopodite length 5.8 exopodite length (vs. 7.8); pereonites 3–4 tergites each with an anterolateral seta (vs. setae lacking) (see also the identification key, Table 4).
(FIGS 20–22)
Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: 820608B2-7BAA-43B1-8B40-3A5561937B8B.
Type fixation: Holotype, preparatory female, ZMH K-55358, 3.4 mm, designated here.
Material examined: Holotype: preparatory female (Na08), 3.4 mm, CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 133 (start: 13°50‘45’’N, 123°15’39’’W, 4516 m; end: 13°51’8’’N, 123°14’8’’W, 4427 m), date: 10/04/2015, ZMH K-55358.
Paratypes: Ovigerous female (Na11), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 171 (start: 14°2’41’’N, 130°5’57’’W, 5024 m; end: 14°3’12’’N, 130°4’36’’W, 5017 m), date: 17/04/2015, ZMH K-55362; preparatory female (Na04), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20 (start: 11°50’9’’N, 117°58’29’’W, 4093 m; end: 11°50’11’’N, 116°58’0’’W, 4093 m), date: 21/03/2015, ZMH K-55361; preparatory female (Na05), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20, ZMH K-55365; preparatory female (Na22), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 24 (start: 11°51’19’’N, 117°1’30’’W, 4093 m; end: 11°51’31’’N, 116°58’0’’W, 4093 m), date: 22/03/2015, ZMH K-55363; preparatory female (NB12_Iso_290), CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 43 (start: 11°48’12’’N, 117°32’3’’W, 4358 m; end: 11°48’20’’N, 117°31’57’’W, 4358 m), date: 09/04/2012, ZMH K-55360; preparatory female (NB12_Iso_330), CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 43, ZMH K-55364; preparatory female (MA13_Iso593), CCZ, equatorial NE Pacific, MA13 expedition, RV Kilo Moana, EBS, station 90 (start: 11°49.718’N, 117°30.278’W, 4340 m; end: 11°49.906’N, 117°29.395’W, 4357 m), date: 03/05/2013, ZMH K-55359; preparatory female (MA13_ Iso049), CCZ, equatorial NE Pacific, MA13 expedition, RV Kilo Moana, EBS, station 07 (start: 11°51.503’N, 117°01.205’W, 4131 m; end: 11°51.756’N, 117°00.171’W, 4121 m), date: 12/04/2013, ZMH K-55357; female, badly damaged (MA14_Iso319), CCZ, equatorial NE Pacific, MA14 expedition, RV Kilo Moana, EBS, station 39 (start: 11°49’37’’N, 117°30’49’’W, 4361 m; end: 11°49’47’’N, 117°30’5’’W, 4343 m), date: 13/05/2014, ZMH K-55367; male, badly damaged (MA14_Iso242), CCZ, equatorial NE Pacific, MA14 expedition, RV Kilo Moana, EBS, station 39, date: 13/05/2014, ZMH K-55366.
Etymology: The name is a noun in apposition, and dedicated to Pedro Martinez Arbizu, Principal Investigator of the JPIO EcoResponse expedition, for his drive and commitment to the exploration of the abyssal manganese nodule fauna.
Distribution: The species has a broad distribution across the CCZ, being collected from the eastern German, GSR (type locality) and French licence areas between 4093 and 5024 m depth.
Diagnosis: Body slender, length about 5.5 × pereonite 1 width; Mxp epipodite reaching mid of palpal article 3; Mxp lateral margin lacking fringe of setae; molar process of both Md each with only a few (≤ 5) distal spines; Md incisor teeth acute; pereonite 2 anterolateral tergites each with robust seta; pereonite 7 without ventral spine; Op with a ventral posteriorly bent spine, posterior margin with numerous (≥ 21) long simple setae; Urp biramous, not projecting beyond Plt posterior margin; Urp endopodite length ≥ 3.2 exopodite length.
Description of holotype and paratype female: Habitus (Figs 20A, B, 22), body length 5.5 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Figs 20A, 22D–E), length 0.7 width. Anterior and posterior margins straight, lateral margin slightly rounded. Antennae inserting frontolaterally in a deep fold. Body abruptly flattening from pereonite 4 to 5. Pereonites 2–4 decreasing in width, pereonites 4–7 of similar width. Pereonite 1 length 0.3 width. Pereonite 1 and 2 of similar width, pereonite 2 length 1.7 pereonite 1 length. Pereonites 3 and 4 of similar length, length 1.2 pereonite 2. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of pereonite 2 each tipped with a robust seta, anterolateral tergites of pereonites 3 and 4 each with a simple seta. Pereonite 5 length 1.8 pereonite 1 length, anterior margin straight. Pereonites 6 and 7 dorsomedially fused, anterior margin of pereonite 6 convex. Plt length 0.2 body length, length 1.2 width, width 0.9 pereonite 1 width, posterior margin strongly rounded; anterior margin concave. Urp length 0.3 Plt length, not projecting beyond posterior margin. AI (Fig. 20C), terminal article broken off, inferred from CLSM (Fig. 22A, E). Length 0.1 body length, with five articles. First article circular and broadest, length 2.3 width. Second article length 0.7 article 1 length, length 1.8 width, with two simple setae distally. Article 3 minute, length 0.1 article 1 length, as long as wide. Article 4 length 0.1 article 2 length, with a long distal projection reaching mid of article 5, with one simple seta distally. Article 5 length 0.9 article 2 length, length 1.2 width, with one aestetasc terminally. AII (Fig. 20D) length 0.4 body length, with six podomere and nine flagellar articles. Podomere articles 1–4 short. Article 5 longest, length 1.2 articles 1–4 length, length 5.4 width. Article 6 length 0.9 article 5 length, length 5.6 width. Flagellar article 1 longest, conjoint (fusion of three articles), length 0.6 podomere article 6 length, length 4.8 width. Flagellar articles 2–4 of similar length, length 0.2 flagellar article 1 length. Flagellar 5 article longest, length 0.3 flagellar article 1 length. Flagellar articles 1–9 decreasing in width distally, each article with 0–3 simple setae distally. Article 9 with seven long slender setae terminally. Md (Fig. 21D, E), palp of right mandible damaged, of left mandible well developed, consisting of three articles almost reaching mid of incisor. Palpal article 2 of lMd length 1.2 article 1 length, with two simple setae laterally. Terminal article length about half article 2 length, tapering distally, with several small setae ventrally and two somewhat longer setae terminally. Incisor process of rMd with three acute teeth, incisor of lMd with six acute teeth and one subdistal tooth. Lacinia mobilis of lMd with three teeth. Spine row of rMd with ten robust spines of varying size and several slender setae in between; dentation decreasing proximally. Spine row of lMd with eight robust spines and several slender setae in between, dentation decreasing, spine size increasing proximally. Molar of rMd and lMd triangular; molar of rMd with four, of lMd with five long, serrate spines distally. MxI (Fig. 21F) outer endite with 17 robust spine-like setae distally. Outer margin with several slender setae. Inner endite width 0.6 outer endite width, several fine setae distally, with two simple setae laterally. MxII (Fig. 21G), outer margin of mesial endite with several setae of varying length, distal margin with numerous long setae of varying length. Mesial endite almost as long as lateral endite. Lateral endite and middle endite each with three strong setae distally. Mxp (Fig. 21C), left and right Mxp connected by three retinacula. Epipodite smooth, triangular, slender, length 3.1 width, reaching mid of palpal article 3. Palpal article 2 width 0.9 length. Article 3 length 0.7 article 2 length, width 1.2 length, with seven robust sensory setae distally. Article 4 length 0.4 article 2 length, width half length. Article 5 length 0.4 article 2 length, width 0.2 length, with two slender setae terminally. Endite distal margin with some robust, dentate setae and several fine setae laterally. Basis length 1.5 width. PI (Fig. 20E) basis length 4 width. Ischium about half basis length, length 2.3 width, with one long simple seta dorsally. Merus length 0.6 ischium length, length 1.4 width, with one long simple seta distodorsally. Carpus length twice merus length, length 3 width, with numerous small setae, membranously embedded, and three long unequally bifid setae in between ventrally. Propodus length 0.6 carpus length, length 2.7 width, with one slender simple seta distodorsally, with numerous small setae, membranously embedded, and two robust unequally bifid setae in between ventrally, with one simple seta distoventrally. Dactylus length 0.6 propodus length, length 4 width, with two slender setae medially, with numerous small setae, membranously embedded ventally. Unguis length 0.6 dactylus length, with two long, slender setae underneath unguis. PII (Fig. 21H) basis length 4.4 width. Ischium length about half basis length, length 2.1 width, with two simple setae distodorsally. Merus length 0.8 ischium length, length 1.6 width, with three simple setae of varying length distodorsally, with one long simple seta distoventrally. Carpus length 2.1 merus length, length 4.2 width, with nine long slender simple setae (one broken off) ventrally. Propodus length 0.7 carpus length, length 4.3 width, with one simple seta distodorsally, with three simple setae ventrally. Dactylus length 0.4 propodus length, length 5.5 width, with three simple setae medially. Unguis length half dactylus length, with two slender setae underneath unguis. PIII (Fig. 21I) basis length 4 width. Ischium length 0.6 basis length, length 1.7 width, with two simple setae of varying length (one underneath) distoventrally. Merus length 0.7 ischium length, length 1.8 width, with two simple setae of varying length distodorsally, with one long simple seta distoventrally. Carpus length 2.3 merus length, length 4.7 width, with nine long simple setae ventrally. Propodus length 0.7 carpus length. Dactylus length 0.3 propodus length, length 4.5 width. Unguis length 0.6 dactylus length, with two slender setae underneath unguis. PIV (Fig. 21J) basis length 3.8 width. Ischium length 0.8 basis length, length 3.5 width. Merus length 0.6 ischium length, length 2.1 width. Carpus length 1.8 merus length, length 4.4 width, with seven long slender simple setae ventrally. Propodus length 0.9 carpus length, length 6.8 width, with two simple setae (underneath) dorsally, with two simple setae ventrally. Dactylus length 0.3 propodus length, length 3.5 width. Unguis damaged. PV (Fig. 21K) basis length 4.6 width. Ischium length 0.8 basis length, length 3.6 width. Merus length half ischium length, length 1.7 width, with two simple setae distodorsally. Carpus length 2.2 merus length, length 4.6 width, with one small simple seta distodorsally, with one slender simple seta medially, with five long, slender simple setae ventrally. Propodus length 0.7 carpus length, length 4.3 width, with nine long simple setae dorsally. Dactylus length 0.4 propodus length, length 6 width. Unguis length 0.7 dactylus length, ventral claw underneath. PVII (Fig. 21L) basis length 5.2 width, with four long setae simple setae ventrally, with one simple seta distoventrally. Ischium length 0.7 basis length, length 2.9 width. Merus length half ischium length, length 1.7 width, with two simple setae distodorsally. Carpus length twice merus length, length 4.2 width, with one simple seta (one broken off) distodorsally, with four simple setae (two long, two broken off) ventrally. Propodus length 0.8 carpus length, length 5 width, with seven long simple setae dorsally, with one simple seta (broken off) distoventrally. Dactylus length 0.4 propodus length, length 6 width. Unguis length 0.7 dactylus length, ventral claw underneath. Op (Fig. 20G) length 1.2 width, with a strong ventral spine, posteriorly bent. Lateral and posterior margins rounded, with several (≥ 21) simple setae, setal size 0.1 Plt length. PlpIII (Fig. 20H) protopodite length 0.9 width, length 0.4 endopodite length. Exopodite half endopodite length, length 1.7 width, tapering in width distally, with numerous short simple setae laterally, with one somewhat longer simple seta distally. Endopodite length 1.6 width, with three long plumose setae distally, distal margin strongly rounded. Urp (Fig. 20I), biramous, length 0.25 Plt length, not projecting beyond Plt posterior margin. Protopodite damaged proximally, with one simple seta distally. Exopodite length 7.3 width, with two simple setae (one broken off) terminally. Endopodite length 3.2 exopodite length, length 6.4 width, with one simple seta laterally, with 6 setae (three long simple, three broken off) terminally.
Remarks: Nannoniscus pedro is most similar to species that are characterized by a slender body (body length ≥ 4.5 pereonite 1 width) as well as those possessing a uropodal exopodite and a ventral opercular spine. The new species most closely resembles N. hilario, but can be differentiated by the following characters: Mxp endopodite reaching mid of palpal article 3 (vs. distal third of palpal article 2 in N. hilario); Md incisor teeth acute (vs. rounded); Urp endopodite length 3.2 exopodite length (vs. 6.3); Op posterior margin with ≥ 21 setae (vs. ≤ nine). Nannoniscus pedro is also similar to N. magdae, but differs from the latter species as follows: robust setae of anterolateral tergites of pereonite 2 present (vs. absent in N. magdae); Md incisor teeth acute (vs. rounded). The new species can be distinguished from N. menziesi by the following characters: molar process of left and right Md with five and four distal spines, respectively (vs. 12 and 16 spines, respectively, in N. menziesi); Urp endopodite length 3.2 exopodite length (vs. 5.4). Nannoniscus pedro differs from N. perunis as follows: Urp endopodite length 3.2 exopodite length (vs. 7.8). Finally, the new species can be distinguished from N. meteori by the following characters: Mxp epipodite length 3.1 width (vs. 6.4 in N. meteori); Urp exopodite length 7.3 width (vs. 3.0); Urp endopodite length 6.4 width (vs. 3.2); Op posterior margin with ≥ 21 (vs. ≤ 15).
NANNONISCUS BRENKEI KAISER, BRIX & JENNINGS,(FIG. 23)
Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: AF031C17-94B8-4274-A079-D113BC1423BC.
Type fixation: Holotype, preparatory female, ZMH K-55370, 2.5 mm, designated here.
Material examined: Holotype: preparatory female (NB12_Iso070), 2.5 mm, CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 33 (start: 11°51’44’’N, 117°3’10’’W, 4133 m; end: 11°51’54’’N, 117°3’8’’W, 4133 m), date: 07/04/2012, ZMH K-55370.
Paratypes: Preparatory female (Na03), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20 (start: 11°50’9’’N, 117°58’29’’W, 4093 m; end: 11°50’11’’N, 116°58’0’’W, 4093 m), date: 21/03/2015, ZMH K-55369; ovigerous female (Na24), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 24 (start: 11°51’19’’N, 117°1’30’’W, 4093 m; end: 11°51’31’’N, 116°58’0’’W, 4093 m), date: 22/03/2015, ZMH K-55371; male (?), badly damaged (MA14_Iso258), CCZ, equatorial NE Pacific, MANGAN 14 expedition, RV Kilo Moana EBS, station 21 (start: 11°49’44.52’’N, 117°00’27.06’’W, 4132 m; end: 11°49’56.76’’N, 116°59’40.62’’W, 4136 m), date: 10/05/2014, ZMH K-55368.
Etymology: The name of the new species (brenkei, Latin genitive, male) is dedicated to Nils Brenke, builder of the Brenke sledge (“Berta”), in recognition of his passion for deep-sea isopod taxonomy.
Distribution: The species is only known from four stations in the eastern German claim of the CCZ (type locality) between 4093 and 4136 m depth.
Diagnosis: Body slender, length about 5.0 × pereonite 1 width; Mxp epipodite reaching mid of palpal article 3; Mxp lateral margin with a fringe of setae; molar process of both Md each with only a few (≤ 5) distal spines; Md incisor teeth rounded; pereonite 2 anterolateral tergites each with robust seta; pereonite 7 without ventral spine; Op with a ventral posteriorly bent spine, posterior margin with numerous (≥ 14) long simple setae; Urp biramous, not projecting beyond Plt posterior margin; Urp endopodite length ≤ 5.8 exopodite length; Plp 3 exopodite 0.6 endopodite length, length 2.5 width, strongly tapering in width distally.
Description of holotype and paratype female: Habitus (Fig. 23A). Body length 5.5 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Fig. 23A), length 0.8 width. Anterior and posterior slightly rounded, lateral margins straight. Antennae inserting frontolaterally in a deep fold. Pereonites 2–4 decreasing in width, pereonites 4–7 of similar width. Pereonite 1 length 0.3 width. Pereonite 1 and 2 of similar width, pereonite 2 length 1.1 pereonite 1 length. Pereonite 3 length 1.3 pereonite 2 length. Pereonite 4 length 1.2 pereonite 2 length. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of pereonite 2 each tipped with a robust seta, anterolateral tergites of pereonites 3 and 4 each with a simple seta. Pereonite 5 length 1.5 pereonite 1 length, anterior margin straight. Pereonites 6 and 7 dorsomedially fused, anterior margin of pereonite 6 convex. Plt length 0.2 body length, length 1.4 width, width 0.8 pereonite 1 width, posterior margin strongly rounded; anterior margin slightly concave. Urp length 0.3 Plt length, not projecting beyond posterior margin. AI (Fig. 23B), terminal article broken off, inferred from holotype (in situ). Length 0.1 body length, with five articles. First article circular and broadest, length 2.1 width, with one small broom seta and one simple seta distally. Second article length 0.9 article 1 length, length 1.6 width, with three long broom setae and one seta (broken off) distally. Article 3 minute, length 0.2 article 1 length, half as long as wide. Article 4 length 0.3 article 2 length, with a long distal projection, with one long broom seta and two simple setae distally. Article 5 length 0.5 article 1 length, as long as wide. AII (Fig. 23B) broken off, only podomere articles 1–4 present; articles quadrangular of similar length and width. Md (Fig. 23C, D), palp of left mandible broken off, of right mandible well developed, consisting of three articles extending beyond distal end of incisor process. Palpal article 2 of rMd length 2.5 article 1 length, with one simple seta and two fringes of small setule laterally. Terminal article length about one-third article 2 length, tapering distally, with several small setae ventrally and three somewhat longer setae terminally. Incisor process of rMd with seven rounded teeth, incisor of lMd with five rounded teeth. Lacinia mobilis of lMd with three teeth. Spine row of rMd with nine robust spines of varying size and several slender setae in between; size increasing proximally. Spine row of lMd with nine robust spines, dentation decreasing, spine size increasing proximally. Molar of rMd and lMd triangular; molar of rMd with five, of lMd with four long, serrate spines distally. Mxp (Fig. 23E), left and right Mxp connected by three retinacula (one broken off). Epipodite smooth, triangular, slender, length 3.6 width, reaching mid of palpal article 3. Palpal article 2 as wide as long. Article 3 length 0.8 article 2 length, width 1.2 length, with four robust sensory setae and two simple setae distally. Article 4 length 0.3 article 2 length, width half length. Article 5 length 0.2 article 2 length, width about half length, with two slender setae terminally. Endite distal margin with some robust, dentate setae and several fine setae laterally. Basis length 0.7 width. PI (Fig. 23F) basis length 4 width, with one simple seta dorsally and two simple setae ventrally. Ischium length 0.6 basis length, length 2.2 width, with one small simple seta ventrally. Merus length 0.6 ischium length, length 1.2 width, with one long simple seta distodorsally and one long simple seta distoventrally. Carpus length twice merus length, length 2.6 width, with one long simple seta distodorsally, with numerous small setae, membranously embedded, and three long unequally bifid setae in between ventrally. Propodus length 0.7 carpus length, length 2.7 width, with one slender simple seta distodorsally, with numerous small setae, membranously embedded, and one small robust unequally bifid seta ventrally. Dactylus length 0.6 propodus length, length 3.1 width, with three slender setae medially, with numerous small setae, membranously embedded ventrally. Unguis length about half dactylus length, with one long, slender seta underneath unguis. Op (Fig. 23G) length 1.3 width, with a strong ventral spine, posteriorly bent. Lateral margins rounded, posterior margin almost straight, with several (≥ 14) simple setae, setal size 0.2 Plt length. PlpIII (Fig. 23H) protopodite length 1.7 width, length 0.7 endopodite length. Exopodite 0.6 endopodite length, length 2.5 width, strongly tapering in width distally, with numerous short simple setae laterally, with one somewhat longer simple seta distally. Endopodite length 2.1 width, with three long plumose setae distally, distal margin strongly rounded. Urp (Fig. 23I), biramous, length 0.3 Plt length, not projecting beyond Plt posterior margin. Protopodite length 1.7 width, with one simple seta distally (broken off). Exopodite length 3.0 width, with two simple setae terminally. Endopodite length 5.8 exopodite length, length 6.0 width, with six setae (three broom setae, three simple of varying length) terminally.
Remarks: The new species is characterized by a slender body, robust spines on the anterolateral tergites of pereonite 2, biramous uropods and a ventral opercular spine, and thus most closely resembles N. hilario, N. menziesi, N. meteori, N. pedro and N. perunis. Nannoniscus brenkei is most similar to N. hilario, but can be differentiated from the latter as follows: molar process of left and right mandible with ≤ five spines distally (vs. ≥ nine spines in N. hilario); Op distal margin with ≥ 14 simple setae (vs. ≤ nine). Nannoniscus brenkei also resembles N. meteori, but differs from the latter as follows: Mxp lateral margin with numerous small simple setae (vs. setae lacking in N. meteori); Urp endopodite length 5.8 exopodite length (vs. 3.9). The new species can be differentiated from N. menziesi by the following characters: Mxp lateral margin with numerous small simple setae (vs. setae lacking in N. menziesi); molar process of left and right mandible with ≤ 5 spines distally (vs. ≥ 12). Nannoniscus brenkei can be distinguished from N. pedro as follows: Md incisor teeth rounded (vs. acute in N. pedro); Mxp lateral margin with numerous small simple setae (vs. setae lacking); Urp endopodite length ≥ 5.8 exopodite length (vs. ≤ 3.2). Finally, the new species differs from N. perunis by the following features: body length ≥ 5.0 pereonite 1 width (vs. ≤ 4.7 in N. perunis); Urp endopodite length 5.8 exopodite length (vs. 7.8); pereonites 3–4 tergites each with an anterolateral seta (vs. setae lacking) (see also the identification key, Table 4).
(FIG. 23)
Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: AF031C17-94B8-4274-A079-D113BC1423BC.
Type fixation: Holotype, preparatory female, ZMH K-55370, 2.5 mm, designated here.
Material examined: Holotype: preparatory female (NB12_Iso070), 2.5 mm, CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 33 (start: 11°51’44’’N, 117°3’10’’W, 4133 m; end: 11°51’54’’N, 117°3’8’’W, 4133 m), date: 07/04/2012, ZMH K-55370.
Paratypes: Preparatory female (Na03), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20 (start: 11°50’9’’N, 117°58’29’’W, 4093 m; end: 11°50’11’’N, 116°58’0’’W, 4093 m), date: 21/03/2015, ZMH K-55369; ovigerous female (Na24), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 24 (start: 11°51’19’’N, 117°1’30’’W, 4093 m; end: 11°51’31’’N, 116°58’0’’W, 4093 m), date: 22/03/2015, ZMH K-55371; male (?), badly damaged (MA14_Iso258), CCZ, equatorial NE Pacific, MANGAN 14 expedition, RV Kilo Moana EBS, station 21 (start: 11°49’44.52’’N, 117°00’27.06’’W, 4132 m; end: 11°49’56.76’’N, 116°59’40.62’’W, 4136 m), date: 10/05/2014, ZMH K-55368.
Etymology: The name of the new species (brenkei, Latin genitive, male) is dedicated to Nils Brenke, builder of the Brenke sledge (“Berta”), in recognition of his passion for deep-sea isopod taxonomy.
Distribution: The species is only known from four stations in the eastern German claim of the CCZ (type locality) between 4093 and 4136 m depth.
Diagnosis: Body slender, length about 5.0 × pereonite 1 width; Mxp epipodite reaching mid of palpal article 3; Mxp lateral margin with a fringe of setae; molar process of both Md each with only a few (≤ 5) distal spines; Md incisor teeth rounded; pereonite 2 anterolateral tergites each with robust seta; pereonite 7 without ventral spine; Op with a ventral posteriorly bent spine, posterior margin with numerous (≥ 14) long simple setae; Urp biramous, not projecting beyond Plt posterior margin; Urp endopodite length ≤ 5.8 exopodite length; Plp 3 exopodite 0.6 endopodite length, length 2.5 width, strongly tapering in width distally.
Description of holotype and paratype female: Habitus (Fig. 23A). Body length 5.5 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Fig. 23A), length 0.8 width. Anterior and posterior slightly rounded, lateral margins straight. Antennae inserting frontolaterally in a deep fold. Pereonites 2–4 decreasing in width, pereonites 4–7 of similar width. Pereonite 1 length 0.3 width. Pereonite 1 and 2 of similar width, pereonite 2 length 1.1 pereonite 1 length. Pereonite 3 length 1.3 pereonite 2 length. Pereonite 4 length 1.2 pereonite 2 length. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of pereonite 2 each tipped with a robust seta, anterolateral tergites of pereonites 3 and 4 each with a simple seta. Pereonite 5 length 1.5 pereonite 1 length, anterior margin straight. Pereonites 6 and 7 dorsomedially fused, anterior margin of pereonite 6 convex. Plt length 0.2 body length, length 1.4 width, width 0.8 pereonite 1 width, posterior margin strongly rounded; anterior margin slightly concave. Urp length 0.3 Plt length, not projecting beyond posterior margin. AI (Fig. 23B), terminal article broken off, inferred from holotype (in situ). Length 0.1 body length, with five articles. First article circular and broadest, length 2.1 width, with one small broom seta and one simple seta distally. Second article length 0.9 article 1 length, length 1.6 width, with three long broom setae and one seta (broken off) distally. Article 3 minute, length 0.2 article 1 length, half as long as wide. Article 4 length 0.3 article 2 length, with a long distal projection, with one long broom seta and two simple setae distally. Article 5 length 0.5 article 1 length, as long as wide. AII (Fig. 23B) broken off, only podomere articles 1–4 present; articles quadrangular of similar length and width. Md (Fig. 23C, D), palp of left mandible broken off, of right mandible well developed, consisting of three articles extending beyond distal end of incisor process. Palpal article 2 of rMd length 2.5 article 1 length, with one simple seta and two fringes of small setule laterally. Terminal article length about one-third article 2 length, tapering distally, with several small setae ventrally and three somewhat longer setae terminally. Incisor process of rMd with seven rounded teeth, incisor of lMd with five rounded teeth. Lacinia mobilis of lMd with three teeth. Spine row of rMd with nine robust spines of varying size and several slender setae in between; size increasing proximally. Spine row of lMd with nine robust spines, dentation decreasing, spine size increasing proximally. Molar of rMd and lMd triangular; molar of rMd with five, of lMd with four long, serrate spines distally. Mxp (Fig. 23E), left and right Mxp connected by three retinacula (one broken off). Epipodite smooth, triangular, slender, length 3.6 width, reaching mid of palpal article 3. Palpal article 2 as wide as long. Article 3 length 0.8 article 2 length, width 1.2 length, with four robust sensory setae and two simple setae distally. Article 4 length 0.3 article 2 length, width half length. Article 5 length 0.2 article 2 length, width about half length, with two slender setae terminally. Endite distal margin with some robust, dentate setae and several fine setae laterally. Basis length 0.7 width. PI (Fig. 23F) basis length 4 width, with one simple seta dorsally and two simple setae ventrally. Ischium length 0.6 basis length, length 2.2 width, with one small simple seta ventrally. Merus length 0.6 ischium length, length 1.2 width, with one long simple seta distodorsally and one long simple seta distoventrally. Carpus length twice merus length, length 2.6 width, with one long simple seta distodorsally, with numerous small setae, membranously embedded, and three long unequally bifid setae in between ventrally. Propodus length 0.7 carpus length, length 2.7 width, with one slender simple seta distodorsally, with numerous small setae, membranously embedded, and one small robust unequally bifid seta ventrally. Dactylus length 0.6 propodus length, length 3.1 width, with three slender setae medially, with numerous small setae, membranously embedded ventrally. Unguis length about half dactylus length, with one long, slender seta underneath unguis. Op (Fig. 23G) length 1.3 width, with a strong ventral spine, posteriorly bent. Lateral margins rounded, posterior margin almost straight, with several (≥ 14) simple setae, setal size 0.2 Plt length. PlpIII (Fig. 23H) protopodite length 1.7 width, length 0.7 endopodite length. Exopodite 0.6 endopodite length, length 2.5 width, strongly tapering in width distally, with numerous short simple setae laterally, with one somewhat longer simple seta distally. Endopodite length 2.1 width, with three long plumose setae distally, distal margin strongly rounded. Urp (Fig. 23I), biramous, length 0.3 Plt length, not projecting beyond Plt posterior margin. Protopodite length 1.7 width, with one simple seta distally (broken off). Exopodite length 3.0 width, with two simple setae terminally. Endopodite length 5.8 exopodite length, length 6.0 width, with six setae (three broom setae, three simple of varying length) terminally.
Remarks: The new species is characterized by a slender body, robust spines on the anterolateral tergites of pereonite 2, biramous uropods and a ventral opercular spine, and thus most closely resembles N. hilario, N. menziesi, N. meteori, N. pedro and N. perunis. Nannoniscus brenkei is most similar to N. hilario, but can be differentiated from the latter as follows: molar process of left and right mandible with ≤ five spines distally (vs. ≥ nine spines in N. hilario); Op distal margin with ≥ 14 simple setae (vs. ≤ nine). Nannoniscus brenkei also resembles N. meteori, but differs from the latter as follows: Mxp lateral margin with numerous small simple setae (vs. setae lacking in N. meteori); Urp endopodite length 5.8 exopodite length (vs. 3.9). The new species can be differentiated from N. menziesi by the following characters: Mxp lateral margin with numerous small simple setae (vs. setae lacking in N. menziesi); molar process of left and right mandible with ≤ 5 spines distally (vs. ≥ 12). Nannoniscus brenkei can be distinguished from N. pedro as follows: Md incisor teeth rounded (vs. acute in N. pedro); Mxp lateral margin with numerous small simple setae (vs. setae lacking); Urp endopodite length ≥ 5.8 exopodite length (vs. ≤ 3.2). Finally, the new species differs from N. perunis by the following features: body length ≥ 5.0 pereonite 1 width (vs. ≤ 4.7 in N. perunis); Urp endopodite length 5.8 exopodite length (vs. 7.8); pereonites 3–4 tergites each with an anterolateral seta (vs. setae lacking) (see also the identification key, Table 4).