Laophontodes gertraudae George 2018, sp. nov.

Laophontodes gertraudae sp. nov.

urn:lsid:zoobank.org:act:B12998BE-6AFC-46F8-8836-B8C142FFCF20

Figs 12–15

The epitheton ‘gertraudae’ is given in fond dedication to Mrs. Gertraud Schoetensack, Hannover (Germany).

Three females and three males collected during research cruiseANT XIII /4 of German RV POLARSTERN (Fahrbach & Gerdes 1997). The material was originally determined as Laophontodes typicus by George (1999, 2005).

Holotype

CHILE: ♀, Chilean Patagonian continental slope, south off Isla Nueva, 55°26.5′ S, 66°14.3′ W, station #40/110, depth 105 m, Multicorer, 17 May 1996, K.H. George leg. (SMF 37114 /1, on 1 slide).

Allotype

CHILE: ♂, collected with holotype (SMF 37115/1–9, on 9 slides).

Paratypes

CHILE: 1 ♂, 1 ♀, collected with holotype (SMF 37116/1, SMF 37117/1; on 2 slides); 1 ♂, 1 ♀, Chilean Patagonian continental slope, 55°47.8′ S, 65°48.8′ W, station #40/106, depth 2550 m, Rauschert-Dredge, 15 May 1996, Martin Rauschert leg. (SMF 37118/1, SMF 37119/1; on 2 slides).

Female

HABITUS (Fig. 12A). Cylindrical, tapering distally, body length (R to end of FR) 317–380 µm (n = 3), posteriorly with lateral bulges. Cphth slightly longer than broad, forming ⅓ of total body length. R small (Figs 12A, 13A), fused to cphth, with 2 sensilla and 1 tube pore on apical margin. Body somites clearly distinct. Posterior margins of thoracic somites with dorsal serration and sensilla arising from small socles; P2–P5-bearing somites additionally with 1 tube pore centrally. Last thoracic and first abdominal somites fused to form genital double somite, juncture detectable by dorsal serration. Abdominal part of GDS with serrated posterior margin and pair of tube pores; second and third abdominal somites dorsally serrated on posterior margins, second somite with fine, third somite with stronger spikes. Penultimate somite without sensilla or tube pores. Telson slightly smaller than preceding somite, FR widely separated proximally. Anal operculum basally with pair of sensilla and moderate spinules at apical margin.

FURCAL RAMI (Fig. 12A–B). Slender, about 5 times longer than broadest part, proximally with tube pore, and with 7 setae: I and II central on outer margin, II slightly longer than I; III subapical on dorsal side;

IV and V apical, IV very narrow and less than half length of V, V tripinnate; VI apical on inner margin, as long as II; VII dorsal, tri-articulated at base, on pedestal surrounded at base by ring of spinules.

ANTENNULE (Fig. 13A –A’). 5-segmented. First segment with 1 bipinnate apical seta, and annular row of long spinules; second segment twice as long as first, medially with spinulose ‘bump’ on posterior margin, distally with 9 bare setae; third segment as long as second, with 7 bare setae and 1 aes; fourth segment smallest, partially overlapped by preceding segment (Fig. 13 A’), with 1 bare seta; fifth segment (Fig. 13A) with 9 bare setae and apical trithek formed by 1 small aes and 2 bare setae.

SETAL FORMULA. 1-1/2-9/3-7+aes/4-1/5-10+aes.

ANTENNA (Fig. 13B, B’, B”). With allobasis. Coxa small, triangular; allobasis with abexopodal row of spinules and 1 bare seta; exp (Fig. 13B ”) represented by small bare seta; enp (Fig. 13B –B’) covered with several spinules, outer apical margin with spinulose frill, inner margin with 2 bare spines and 1 slender bare seta, plus 5 apical elements, 3 of which geniculate.

MD, MXL, MX AND MXP. Described from male.

SWIMMING LEGS. P1 (Fig. 14A) with lengthwise elongated coxa; basis as long as coxa, with 1 bipinnate outer seta and 1 uniplumose seta displaced to anterior surface. Enp 2-segmented, enp-1 strong and elongated, with row of spinules on outer and inner margins; enp-2 small, less than ⅓ length of enp-1, apically with claw and 1 slender geniculate bare seta, and subapically with small bare seta. Exp 3-segmented, half the length of enp-1. Exp-1 with 2 spinules and uniplumose spine on outer margin; exp-2 with outer row of spinules and 1 long bare geniculate outer seta; exp-3 with 4 long bare geniculate setae. P2–P4 (Fig. 14B– D) with transversely elongated bases, 3-segmented exopods and 2-segmented endopods. All exopodal segments with row of spinules on outer margin, exp-1 and exp-2 additionally with fine spinules sparsely on inner margin; exopods without inner setae; exps-1 and 2 with bipinnate outer spine; exp-3 longest, with 3 bipinnate outer spines, and apically with 1 bipinnate outer seta and 1 biplumose inner seta. P2– P4 enp-1 small, without spinules and setae; enp-2 elongate, spinulose, with 2 biplumose apical setae. P5 (Fig. 14E) benp represented by 2 setae, one biplumose and one of fish-bone aspect; tube pores not discernible. Outer apical margin with setophore accompanied by long spinules and carrying 1 bare seta. Exp fused to benp, slender, carrying 2 outer, 1 subapical and 2 apical setae, all but one bipinnate.

GENITAL FIELD (Fig. 13C). With single gonopore; P6 strongly reduced, limbs fused, with a small bare spine on each side.

Male

The male differs from the female in the following characters: body size, A1, P3 endopod, P5, no GDS. The mouthparts are of same shape as in the female.

HABITUS (Fig. 12C). As in female, but smaller (body length from rostral tip to end of FR: 276–312 µm (n = 3) and narrower.

ANTENNULE (Fig. 15A –A’). 6-segmented, chirocer. First segment as in female apically with 1 bipinnate seta and annular row of long spinules; second segment medially with spinulose ‘bump’ on posterior margin and 8 bare setae; third segment with 4 bare setae; fourth segment (Fig. 15 A’) minute, almost completely surrounded by segments 3 and 5, with 1 bare seta; fifth segment (Fig. 15A –A’) swollen, antero-ventrally with 9 bare setae and 1 strongly sclerotized bare spine, additionally with aes and accompanying seta arising together from pedestal; sixth segment tapering distally, with 9 bare setae, and small aes and 2 bare setae forming trithek.

SETAL FORMULA. 1-1/2-8/3-4/4-1/5-11+aes/6-11+aes.

MANDIBLE (Fig. 15B). With slender gnathobase bearing 5 teeth; md palp 1-segmented, with 4 lateral setae and 1 terminal bipinnate seta.

MAXILLULE (Fig. 15C). Praecoxal arthrite with 5 strong bare spines, 2 subapical setae and 2 surface setae. Coxa without spinules, terminally with 1 bare seta. Basis without spinules, terminally with 1 bare and 1 bipinnate seta, laterally with 1 bipinnate seta between basal endite and enp. Exp and enp each represented by 1 bipinnate seta.

MAXILLA (Fig. 15D). Syncoxa bearing 2 rows of spinules and 2 endites. Proximal and distal endites with 2 and 3 bare setae, respectively. Basis distinct, produced into strong claw, with 1 seta. Enp 1-segmented and small, with 2 bare setae.

MAXILLIPED (Fig. 15E). Syncoxa apically with scant spinules and 1 biplumose seta; basis longer than syncoxa, with row of spinules on anterior surface and long spinules on posterior margin; enp formed into long bare claw reaching length of basis, with minute bare basal seta.

SWIMMING LEGS. P3 (Fig. 15F) exp as in female. Enp 3-segmented; enp-1 minute and unarmed; enp-2 longest, with row of spinules on both inner and outer margin, without setal elements but with apophysis on inner apical margin, reaching almost the length of enp-3; enp-3 half as long as enp-2, with 2 biplumose apical setae. P5 (Fig. 15G) benp small with 1 outer seta arising from elongated setophore that is surrounded by long spinules at base with 1 tube pore; endopodal part of benp virtually absent, represented by 1 bipinnate seta reaching length of exp. Exp fused to benp, with 1 outer, 1 subapical, and 1 apical seta, all bipinnate.