Leucothoe weddellensis Krapp-Schickel & Broyer 2014, sp. nov.

Leucothoe weddellensis sp. nov.

urn:lsid:zoobank.org:act: 2069CF2D-D7B6-4A96-874A-46818C6A3344

Figs 19-27

sub L. spinicarpa variant 1 – Holman & Watling 1983: 227-230 fig. 10 (but see also discussion about L. spinicarpa variant 1 and 2).

Etymology

The latinized adjective refers to the fact that much of the material comes from the Weddell Sea.

Type material

Holotype ♀ ov. 20 mm (in alcohol) (RBINS, Brussels, I.G. 31073/ INV. 103464); Polarstern ANT XIX/3 (ANDEEP I): sta. PS61/067 GSN; 4 Feb. 02; Scotia Sea, north to Elephant Island; 60°55’53”S, 55°27’38”W to 60°55’09”S, 55°24’50”W; 115-182 m; bottom trawl; coll. C. De Broyer, P. Dauby & F. Nyssen.

Preliminary remarks

Before starting to cite the localities, we have to explain the division in two parts:

Quite like Holman & Watling (loc. cit.) we hesitated between attributing the entire material to one species, or dividing the material into two new species. Like the cited authors we first separated the material into two different size classes with large or small ovigerous females, but then could not find any clearcut morphological definition which would not show here or there intermediate structures. Unfortunately, we have no clue about the life span of these females and how often they become ovigerous, thus all the observed tiny differences could also be due to allometry.

Therefore we kept the locality citations separated and first gave information about the smaller specimens, followed by the larger ones. This might help to continue gathering observations within this so puzzling genus.

Diagnosis for the material of 6-14 mm length

Eyes big, round. Mandibular palp ratio art. 3:art. 2 = 0.6. Cx 3 tongue-shaped rounded, smooth. Gn 1 propodus l:w = 5, dactylus reaching 1/4-1/3 of propodus length. P 5-7 basis narrow oval, P 5, 6 with slightly concave hind margin, P 7 hind margine serrate, ratio l:w about 2. Ep 2, 3 posterodistally with small rounded upturned corner. T l:w = 3.

Additional smaller specimens

Australian Museum, Sydney

P. 25977: 1 Feb. 1971; Ross Sea, Ross Island, Cape Bird, Southern Rookery; 77.2°S, 166.4° E; 83 m depth: 1 spec. 10 mm.

P. 25978: sta. C3-C4; 14 Dec. 1971; Ross Sea, Ross Island, Cape Bird, Southern Rookery; 77.2°S, 166.4°E; 85 m depth; spionid polychaete bottom: 1 spec. 14 mm.

P. 25979: 30 Jan. 1971; Ross Sea, Ross Island, Cape Bird, Southern Rookery; 77.2°S, 166.4° E; 61 m depth: 3 spec. 10 mm, 9 mm, 6 mm.

P. 25980: sta. R13; 9 Feb. 1971; Anvers Island, Arthur Harbour; 64.8°S, 64.1°W; 23 m depth; sand 50%, silt 44%, clay 7%: 1 spec. 6.5 mm.

P. 25981: sta. R13; 9 Feb. 1971; Anvers Island, Arthur Harbour; 64.8°S, 64.1°W; 23 m depth; sand 49.9%, silt 43.78%, clay 7.14%: 1 spec. 7 mm.

P. 34272: 8 Jan. 1982; Davis Station; 68.6°S, 78°E; 15 m depth; rock and silt: 1 spec. 13 mm, 1 juv.

P. 81141: 14 Jan. 1971; Ross Sea, MacMurdo Sound, Ross Island, Cape Bird; 77.2°S, 166.4° E; 110 m depth: 1 spec. 10 mm.

Belgian-Dutch Antarctic Expeditions

(RBINS, Brussels: EABN 1966-67, coll. M. Steyaert & M. Meisch, RBINS I.G. 23694)

EABN 1966-67: sta. 220; 3 Feb. 1967; Breidbay, Baie Léopold; 70°19’S, 24°14’E; 200 m: 2 spec. 13 and 14 mm.

EABN 1966-67: sta. 236; 3 Feb. 1967; Breidbay, Baie Léopold; 70°19’S, 24°14’E; 200 m: 1 spec. 12 mm.

British Antarctic Survey, Cambridge

Sta. SG-EBS 3-5; 5 Apr. 2006; South Georgia; 54°15’S 36°45’W; 300-500 m: 1 spec. 6 mm.

NIWA, Wellington

NIWA 20425: sta. Tangaroa TAN 0402/15; 5 Feb. 2004; north-eastern Ross Sea, near Cape Adare; 71.7278°S, 171.7353°E to 71.7308°S, 171.7445°E; 466-467 m: 1 spec. 11 mm.

NIWA20427: sta. Tangaroa TAN 0402/54; 13 Feb. 2004; north-eastern Ross Sea; 72.3248°S, 170.4277°E to 72.3315°S, 170.4287°E; 206- 199 m; 1 spec. 13 mm

NIWA 20428: sta. Tangaroa TAN 0402/94; 17 Feb. 2004; north-eastern Ross Sea; 71.5299988°S, 170.1109924°E to 71.5234985°S, 170.1131744°E; 220- 191 m; 1 spec. 11 mm.

NIWA 20873: sta. Tangaroa TAN 0402/14; 5 Feb. 2004; north-eastern Ross Sea; 71.7313309°S, 171.7500000°E; 451 m: 1 spec. 9 mm,

NIWA 20874: sta. Tangaroa TAN 0402/129; 19 Feb. 2004; north-eastern Ross Sea; 71.3268356°S, 170.4515076°E to 71.3268356°S, 170.4515076°E, 120 m,. 1 spec. 10 mm,

NIWA 21022: sta. Tangaroa TAN 0402/111; 18 Feb. 2004; north-eastern Ross Sea; 71.3044968°S 170.6179962°E; 357 m: 1 spec. 10 mm.

Polarstern cruises

(ANT VII/4 (EPOS 3), coll. C. De Broyer & M. Klages, RBINS I.G. 27497; ANT XIII/3 (EASIZ I), coll. C. De Broyer & G. Chapelle, RBINS I.G. 28252; ANT XV/3 (EASIZ II), coll. C. De Broyer & Y. Scailteur, RBINS I.G. 28252; ANT XXI/2 (BENDEX), coll. C. De Broyer, RBINS I.G. 31072; ANT XXIII-8, coll. C. d’Udekem d’Acoz & H. Robert, RBINS I.G. 31070)

ANT VII/4 (EPOS 3): sta. PS14/245 GSN9; 2 Feb. 1989; eastern Weddell Sea; 74°40’S, 29°40’W; 483 m; bottom trawl: 3 spec. 14 mm; 2 smaller ones.

ANT VII/4 (EPOS 3): sta. PS14/245 AGT9; 2 Feb. 1989; eastern Weddell Sea; 74°40’S, 29°42’W; 509 m; Agassiz Trawl: 1 spec. ♀ 12 mm.

ANT XIII/3 (EASIZ I): sta. PS39/006 AGT1; 8 Feb. 1996; eastern Weddell Sea; 71°31’S, 13°34’W to 71°31’S 13°35’W; 254-261 m; Agassiz Trawl: 2 spec. 11 and 13 mm and one damaged.

ANT XIII/3 (EASIZ I): sta. PS39/011 GSN4; 13 Feb. 1996; eastern Weddell Sea; 73°22’S, 21°10’W to 73°23’S, 21°12’W; 333-338 m; bottom trawl: 1 spec. 14 mm with orange spots.

ANT XIII/3 (EASIZ I): sta. PS39/016 GSN; 15 Feb. 1996; eastern Weddell Sea; 73°53,40’S, 22°26,90’W; 246 m; bottom trawl: 1 spec. 11 mm.

ANT XIII/3 (EASIZ I): sta. PS39/026 D; 24 Feb. 1996; eastern Weddell Sea, 71°29’S, 14°19’W to 71°29’S, 14°19’W; 210-214 m; dredge 21; coll. Rauschert: 2 spec.

ANT XV/3 (EASIZ II): sta. PS48/044 AGT; 30 Jan. 1998; eastern Weddell Sea, north of Kapp Norvegia; 70°51’48”S, 10°34’W to 70°51’54”S, 10°33’48”W; 227-229 m; Agassiz Trawl: 1 spec. 14 mm.

ANT XV/3 (EASIZ II): sta. PS48/049 AGT; 30 Jan. 1998; eastern Weddell Sea; 70°52’S, 10°27’18”W to 70°51’54”S, 10°26’48”W; 255-261 m; Agassiz Trawl: 1 spec. 12 mm.

ANT XV/3 (EASIZ II): sta. PS48/077 AGT; 2 Feb. 1998; eastern Weddell Sea; 71°09’42”S, 12°28’42”W to 71°09’54”S, 12°29’12”W; 341-360 m; Agassiz Trawl: 1 spec. 13 mm.-

ANT XV/3 (EASIZ II): sta. PS48/078 GSN; 3 Feb. 1998; eastern Weddell Sea; 72°51’06”S, 19°15’06”W to 72°50’54”S, 19°18’42”W; 390-391 m; bottom trawl: ♂ 14 mm, with orange spots in alcohol.

ANT XV/3 (EASIZ II): sta. PS48/082 GSN; 3 Feb. 1998; eastern Weddell Sea, Drescher Inlet; 72°50’48”S, 19°18’48”W to 72°50’48”S, 19°21’54”W; 395-417 m; bottom trawl: 2 spec. 13 mm.

ANT XV/3 (EASIZ II): sta. PS48/154 GSN; 11 Feb. 1998; eastern Weddell Sea, Halley Bay; 74°38’42”S, 26°59’W to 74°39’12”S, 27°01’12”W; 569-583 m; bottom trawl: 3 spec. 10-13 mm.

ANT XV/3 (EASIZ II): sta. PS48/206 GSN; 18 Feb. 1998; eastern Weddell Sea, Kapp Norvegia; 71°00’24” S, 11°42’36”W to 71°00’42”S, 11°42’30”W; 594-602 m; bottom trawl: 1 spec. 12 mm.

ANT XV/3 (EASIZ II): sta. PS48/222 GSN; 19 Feb. 1998; eastern Weddell Sea, Kapp Norvegia; 70°50’30”S, 10°35’30”W to 70°51’S, 10°35’30”W; 234-267 m; bottom trawl: 1 spec. 12 mm.

ANT XXI/2 (BENDEX): sta. PS65/29 AGT; 25 Nov. 2003; Bouvet Island; 54°31,59’S, 03°13,05’E; 377 m; Agassiz Trawl; in sponge, 56 m: 2 spec. 10 and 12 mm.

ANT XXIII/8, sta. PS69/RD 726-1; 23 Jan. 2007; Snow Hill Island; 64°30.86’S, 56°40.23’W; 197 m; Rauschert dredge; ♀ ov. 14 mm, 2 spec. 12 mm.

Description

Length

Up to 14 mm

Head

Anterior margin rounded, anterodistal margin rectangular with rounded corner. Mid-cephalic keel prominent. Rostrum small, curved.

Eyes large, round. Antenna 1 one third of body length, flagellum 10-14-articulate, peduncle art. 1 width proximally less than twice article 2, disto-inferiorly without acute tooth, length art. 1 subequal art. 2, art. 3 about 1/2 of art. 2, acc. flagellum not seen. Peduncle art. 3 + flagellum shorter than peduncle arts 1+2.

Antenna 2 subequal in length with antenna 1, peduncle art. 4 clearly longer art. 5, flagellum 9-10 arts.

Mouthparts: Mandibles lacking molars, incisor and lacinia mobilis dentate; palp 3-articulate, art. 2 with many lateral setae of different length, art. 3 with 2 distal setae, art. 3> 1/2 art. 2. Maxilliped IP small, OP very short; palp articles similar in length.

Peraeon

Cx 1 smooth, length> width; anterior margin smooth, facial setae absent, inferior margin smooth.

Gn 1 basis not inflated, both margins with short setae; carpus basis more than half as long as propodus, distal part linear and narrow, about 10 x longer than wide; propodus straight, about 5 x as long as wide, palm minutely dentate with 9 short setae; dactylus smooth, reaching up to 1/3 propodus length.

Cx 2 subquadrangular, about as long as wide, much wider than Cx 3, distally smooth; anterior margin convex, anterodistal corner rectangular, inferior margin straight, facial setae absent.

Gn 2 basis scarcely inflated, many short setae on anterior margin; carpus nearly reaching half propodus length, curved, distally truncate, densely setose; propodus anterodistally with short prolongation and a bundle of setae, posterior margin with many low humps, palm convex, proximally near dactylus-end no corner; dactylus curved, both margins smooth, bare, reaching more than half of propodus length.

Cx 3 length> width, distally obliquely rounded, tongue-shaped, smooth, facial setae absent.

Cx 4 length subequal to width, smooth, bare, anterior margin convex, distal margin rounded, posterior margin shorter than anterior one, excavate, facial setae absent.

P 3, 4 basis very narrow, a bit wider than merus; dactylus reaching less than half length of propodus, posterior margins with some short thin spines.

Cx 5-7 facial setae absent.

P 5-7 similar, bases l:w ratio up to 2, anterior margins with very slight serrations and small weak spines, posterior margins in P 5, 6 smooth, in P 7 weakly. Merus in P 5-7 with posterodistal corner lengthened.

Pleon

Ep 1-3 without spines or setae. Ep 2 posteroventral corner not acutely upturned, but produced with rounded corner, Ep 3 posteroventral corner blunt and rectangular.

Uropods: U 1 with somewhat unequal rami, the shorter one shorter than peduncle; U 2 the shortest, with unequal rami, the shorter one subequal to peduncle; U 3 with equal rami much shorter than peduncle.

Telson ratio l:w = 3.

No sexual difference noticed.

Distribution

Circum-Antarctic (54°- 77°S, 10°- 64°W and 03°- 171°E).

Depth range

15- 602 m.

Remarks

In Holman & Watling (1983: 227, fig. 11: upper part, L. spinicarpa variant 2) only few sketches of females of 6-6.5 mm are given which could match the here described specimens of 10-14 mm. On p. 229 the authors wrote: “[...] smaller specimens [in comparison to the following species of 20 mm] tending not to have this tooth [on Ep 3 posterodistal corner] or distinctive shape of Cx 3.[...] At stations where both variants 1 and 2 occurred, there is also a clear size dichotomy.”

Diagnosis for the material of 14-24 mm length

Eyes large, round. Cephalic keel acute. Mandibular palp ratio art. 3:art. 2 = 0.3. Cx 3 in large specimens distal margin excavate, posterodistal corner lengthened and tongue-shaped rounded, smooth, in smaller ones without this character. Gn 1 propodus l:w = 5-6, dactylus reaching 0.4 of propodus length. P 5-7 basis pear-shaped oval, all with convex and serrate hind margin, ratio length to width 1.7-1.8. Ep 1 posterior margin serrate, Ep 2 posterodistally with acutely lengthened but not much upturned corner, Ep 3 posteriordistal corner rectangular, with small prolongation. T l:b = 3.

Additional larger size material

NIWA, Wellington

NIWA 9062: sta. LOCVI-2; Ross Sea, west to Beaufort Island; 77.8327789°S, 166.6138916°E; 28 Dec. 1959, 9- 19 m, 1 spec. 15 mm,

NIWA 17881: Tangaroa sta. TAN 0402/53; 13 Feb. 2004; north-eastern Ross Sea; 72.3310013°S, 170.4278259°E; 197 m: 1?juv. 10 mm.

NIWA 20426: Tangaroa sta. TAN 0402/67; 13 Feb. 2004; north-eastern Ross Sea; 72.3209991°S, 170.4751740°E to 72.3345032°S 170.4813385°E; 272-286 m: 1 spec. 13 mm

NIWA 20429: Tangaroa sta. TAN 0402/108; 18 Feb. 2004; north-eastern Ross Sea; 71.2718353°S, 170.5996704°E to 71.2773361°S 170.6151733°E; 400-405 m: 1 spec. 13 mm,

NIWA 20430: Tangaroa sta. TAN 0402/112; 18 Feb. 2004; north-eastern Ross Sea; 71.2935028°S, 170.5766602°E to 71.2961655°S 170.5908356°E; 346-351 m: 1 spec. 17 mm.

NIWA 20431: Tangaroa sta. TAN 0402/133; 23 Feb. 2004; north-eastern Ross Sea; 71.6446686°S, 170.2188263°E to 71.6470032°S 170.2243347°E; 249-252 m: 1 spec. 15 mm.

Polarstern cruises

(ANT XV/3 (EASIZ II), coll. C. De Broyer & Y. Scailteur, RBINS I.G. 28252; ANT XIX/3 (ANDEEP I), coll. C. De Broyer, P. Dauby & F. Nyssen, I.G. 31073)

ANT XV/3 (EASIZ II): sta. PS48/078 GSN; 3 Feb. 1998; eastern Weddell Sea; 72°51’06”S, 19°15’06”W to 72°50’54”S, 19°18’42”W; 390-391 m; bottom trawl: ♂ 16 mm, with orange spots.

ANT XV/3 (EASIZ II): sta. PS48/062AGT; 31 Jan. 1998; eastern Weddell Sea; 70°53’36”S, 10°28’06”W to 70°53’42”S, 10°28’12”W; 235-241 m; Agassiz Trawl: 1 spec. 12 mm in 3 slides, 2 spec. 13 mm, 20 mm, all without eggs.

ANT XIX/3 (ANDEEP I): sta. PS61/047-I; 30 Jan. 2002; north of Elephant Island; 61°04,18’S, 54°36,81’W; 190 m; bottom trawl: 9 spec. 18-20 mm.

ANT XIX/3 (ANDEEP I): sta. PS61/048-1; 30 Jan. 2002; east of Elephant Island; 61°09,82’S, 54°33,40’W; 343 m; bottom trawl: 1 spec. 20 mm.

ANT XIX/3 (ANDEEP I): sta. PS61/067 GSN; 4 Feb. 2002; north of Elephant Island; 60°55’53”S, 55°27’38”W to 60°55’09”S, 55°24’50”W; 115-182 m; bottom trawl: 1 spec. 20 mm.

Polish Antarctic Expeditions (LPBO-UL, Łódź)

Polish Ant. Exp. 2007, sta. Profile B II/4; 27 Mar. 2007; King George Island,Admiralty Bay; 62°09,643’S, 58°30,182’W; 112 m; Van Veen Grab; 1 spec. 19 mm.

Polish Ant. Exp. 2007, sta. Profile B I/1; 27 Mar. 2007; King George Island, Admiralty Bay; 62°09,703’S, 58°30,272’W; 109 m; Van Veen Grab: 1 spec. 10 mm.

Victoria Museum, Melbourne

J 38264: Aurora Australis, sta.AA93-127; Lot 414; 12 Feb. 1993, 67°16.12’S, 65° 25.23’E; Mac Robertson Shelf, edge of Nielsen Basin; 109 m: 1 ov. ♀ 15 mm.

Description

Length

Up to 24 mm.

Head

Anterior margin rounded, anterodistal margin rectangular with rounded corner. Mid-cephalic keel acute. Rostrum small, curved.

Eyes large, round.

Antenna 1 one third of body length, flagellum 20-articulate, peduncle art. 1 width proximally less than twice article 2, distally without acute tooth, length art. 1> art. 2, art. 3 about 1/3 of art. 2, acc. flagellum not seen. Peduncle art. 3 + flagellum shorter than peduncle arts 1+2.

Antenna 2 subequal in length to antenna 1, peduncle art. 4 clearly longer art. 5, flagellum 10-16 arts.

Mouthparts: Mandibles lacking molars, incisor and lacinia mobilis dentate; palp 3-articulate, art. 2 with many lateral and some distal setae of different length, art. 3 with 3 distal setae, art. 3 = 1/2 art. 2. Maxilliped IP small, OP absent; palp articles similar in length.

Peraeon

Cx 1 smooth, length = width; anterior margin smooth, facial setae absent, inferior margin smooth.

Gn 1 basis not inflated, both margins smooth; carpus basis about half as long as propodus, distal part linear and narrow, about 8 x longer than wide; propodus straight, about

4.5 x as long as wide, palm smooth with 7-8 short setae; dactylus smooth, reaching 2/5 propodus length.

Cx 2 subquadrangular, about as long as wide, much wider but shorter than Cx 3, distally smooth; anterior margin convex, anterodistal corner rectangular, inferior margin straight, facial setae absent.

Gn 2 basis not inflated, many short setae on anterior margin; carpus nearly reaching half propodus length, curved, distally excavate in male, rounded in female, densely setose; propodus anterodistally with short, acute prolongation and a bundle of setae, posterior margin with many low humps, palm convex, proximally near dactylus-end no corner; dactylus curved, both margins smooth, bare, reaching more than half of propodus length.

Cx 3 length> width, anterior and posterior margin straight, distal margin oblique and excavate, posterodistal corner in large animals tongue-shaped and lengthened, smooth, facial setae absent.

Cx 4 length subequal to width, smooth, bare, anterior margin rounded, distal margin straight to excavate, posterior margin shorter than anterior one, straight to slightly excavate, facial setae absent.

P 3, 4 basis very narrow, a bit wider than merus; dactylus reaching less than half length of propodus, posterior margins with some short thin spines.

Cx 5-7 facial setae absent.

P 5-7 similar, bases l:w ratio 1.7-1.8, anterior margins with very small spines, posterior margins serrate. Merus in P 5-7 with posterodistal corner lengthened.

Pleon

Ep 1-2 with spines anterodistally. Ep 2 posteroventral corner not upturned, but produced with acute corner, Ep 3 posteroventral corner rectangular with small rounded prolongation.

Uropods: U 1 with equal rami, shorter than peduncle; U 2 the shortest, with unequal rami, the shorter one clearly shorter than peduncle; U 3 with slightly unequal rami much shorter than peduncle.

Telson ratio l:w = 3.

Distribution of the larger specimens

Circum-Antarctic (60°- 78°S, 10°- 58°W and 65°- 170°E).

Depth range

9- 405 m.

Holman & Watling (1983) recorded “ L. spinicarpa variant 1” in the Drake Passage, south of Tierra del Fuego (Eltanin 9, sta. 740; 18 Sep. 1963; 56°06-07’S, 66°19’-30’W; 384-494 m), on the South Georgia shelf (Islas Orcadas 575, sta. 82; 6 Jun. 1975; 55°29.0’S, 35°20.5’W; 413-462 m; sta. 90; 7 Jun. 1975; 54°50.6’S, 37°23.8’W; 223-227 m), in the Scotia Sea (Eltanin 6, sta. 410; 31 Dec. 1962; 61°18’-20’S, 56°09’-10’W; 220-240 m) and north of the Antarctic Peninsula (Eltanin 12, sta. 1003; 15 Mar. 1964; 62°41’S, 54°43’W; 210-220 m).

Remarks

In Holman & Watling (1983: 227, Fig. 10) males are illustrated which are 19-24 mm long and match perfectly to the here illustrated material of 20 mm. Holman & Watling (l.c.: 229) defined their variant 1 as follows: “...ventral margin of coxa 3 bilobed in larger specimens, coxa 4 not excavate posteriorly. Gnathopod 1 very similar to that illustrated by Sars (1895) for L. spinicarpa, dactyl nearly half length and twice width of propodus, latter 5 times as long as wide. Gnathopod 2, distal margin of article 5 bifurcate in large males. Third epimeron posterodistal corner with small tooth but without distinct sinus above; however, smaller specimens tending not to have this tooth or distinctive coxa 3 shape....”

Differences to the smaller material are, besides the nearly double length of mature females, the length of Md palp art. 3 (we doubt that there can be such a strong allometry), the shape of Cx 3, P 5-7 basis and U 3 rami. However, the main reason of our hesitation is that we found samples with both small and larger ovigerous females, and with larger specimens with and smaller ones without the characteristic shape of Cx 3 living together.

Within all hitherto known Leucothoe species only L. serraticarpa Della Valle, 1893 has a distal lobation on a coxa in large specimens (like here on Cx 3), but in the former it is in Cx 4 and has a different shape.