Gosbia pusilla gen. et sp. nov.

(Figs. 278, 279)

Typematerial. Holotype (intact ♀, MNHN-IU-2014- 21344), paratypes (2 intact ♀♀, MNHN-IU-2014-21345), anddissectedparatype (♀, figured) from Minipera papillosa Monniot C. & Monniot F., 1974, BIOGAS$ cruise, Stn DS55, Gulf of Gascogne, off Atlantic coast of France, “Jean Charcot” (47°35’N, 09°41’W), depth 4125 m, 22 February 1974.

Additional material. 1 ♀ (dissected) from M. papillosa, BIOGAS 4 DS75, Gulf of Gascogne (47°31 Ń, 9°07.8 Ẃ), depth 2906 m, 23 February 1974; 1 ♀ (MNHN-IU-2018-1881) from M. papillosa, West Ireland, Chain 106; 1 ♀ (MNHN-IU-2018-1882) from M. papillosa, Southwest Ireland, Chain 106 Stn 326, depth 3859 m, 1972.

Etymology. The specific name is derived from the Latin pusill (=very small) and refers to the small body of the new species.

Descriptionoffemale. Body (Fig. 278A) small, slightlydepressed; bodylength 773 μm. Prosome 480 μm long, consisting of relatively large cephalosome and 4- segmented metasome, with thin, soft cuticle: dorsal and ventral margins of prosome nearly parallel: pedigerous somites defined only by dorsal and lateral constrictions. Freeurosome (Fig. 278B) 5-segmented: genitalsomite 23×98 μm;4 abdominalsomites39×83,41×71, 32×65, and 59×67 μm, respectively. Surface of posterior abdominal somites ornamented with long setules. Caudal ramus (Fig. 278C) about 4.2 times longerthan wide (74×17.5 μm) and gradually narrowing distally, ornamented with scattered setules: armed with 6 setae; setae longerthan maximum width of ramus; 2 proximal setae located at 24 and 36% of ramus length.

Rostrum (Fig. 278D) large, elongate, 71×35 μm, narrowing distally, constricted near proximal third, with small notch in apex. Antennule (Fig. 278E) 112 μm long, 8-segmented; armatureformula 2, 15, 5, 3, 2, 3, 5 and 7+aesthetasc; larger seta on first segment pinnate, all other setae naked.Antenna (Fig. 278F) 4-segmented; coxa unarmed; basis 29×17 μm, armedwith 1 large, pinnate seta (37 μm long) representing exopod at outer distal corner; first endopodal segment 35×17 μm, unarmed, slightly longer than basis; compound distal endopodal segment about 4.2 timeslongerthan wide (50×12 μm) and ornamented with row of spinules on distal part of outer margin: armedwith 6 setae (arranged as 1, 2, and 3) plus slender terminal claw, 22 μm long, less than half length of segment.

Labrum (Fig. 278G) with large, spinulose posteromedian lobe and convex posterior margin ornamented with setules on both sides. Mandible (Fig. 278H) with coxa bearing 5 teeth and 2 small setae on cutting margin of gnathobase: basis with 1 seta on medial margin; exopod with 4 setae; second and third setae longerthan first and fourth; endopod with 1 and 5 setae on first and second segments, respectively; mediodistal seta on second segment much longerthan other setae on either ramus. Maxillule (Fig. 278I) armedwith 5 setaeon arthrite, 1 on each coxal endite and epipodite, 2 on basis, 3 on exopod and 2 on endopod; exopod and endopod small but clearly defined. Maxilla (Fig. 278J) 4-segmented; syncoxa with 9 setae arranged as 3, 1, 2, and 3; basis with strong claw bearing minute spinules on concave margin plus 2 unequal setae (proximal seta needle-like); endopod 2-segmented with 1 setaon first, and 4 setaeon second segment. Maxilliped (Fig. 278K) unsegmented, tapering distally, with traces of 2 transverse suture lines; armed with 10 medial setae and 1 apical seta.

Legs 1–4 biramous with 3-segmented rami (Fig. 279 A-C); coxalacking inner seta; outersetaonbasis shorter than first exopodal segment. Inner distal spine on basis of leg 1 slender, spinulose, 23 μm long. First endopodal segment of leg 1 with pointed outer distal corner; second endopodal segment with bicuspid outer distalcorner. Setaeonleg 4 shortand naked. First exopodal segment of leg 4 lacking outer element. Armature formula for legs 1–4 as in generic diagnosis.

Leg 5 (Fig. 278B, L) rudimentary, represented by 2 small lobes each tipped with naked seta.

Male. Unknown.

Remarks. This copepod is a deep-water species. Its host Minipera papillosa is distributed across a wide depth range (750 to 6000 m) in the Atlantic Ocean (Monniot & Monniot, 1987).