Haploops vallifera Stephensen 1925

Haploops vallifera Stephensen 1925.

(Figures 9–12)

BIOFAR material examined. Station 124, one specimen, 26 July 1987, depth 600 m, 62°16.94’N – 09°38.93’W; sediment type unknown. Station 261, nine specimens, 14 May 1988, depth 1003 m, 61°35.57’N – 09°35.47’W; sediment type unknown. Station 731, 182 specimens, 29 September 1990, depth 1042 m, 60°29.70’N – 07°14.10’W; bottom: sand, gravel, cobbles and stones. Station 738, one specimen, 1 October 1990, depth 749 m, 62°19.30’N – 10°13.30’W; bottom: gravel, cobbles and stones.

Male unknown.

Diagnosis. Body with few small dorsal setae on the pereon and the pleon. Corneal lenses absent. Segments of dorsal side of mesosome, marked. Urosome segment 1 with a small rounded carena. Epimeral plate 3 rounded. The two pairs of antennae of equal length not longer than half of body.

Description. (Fig. 9–12). Adult female (Fig. 9) length 6 mm Biofar 731.

Head: nearly square, with a small rostrum, without corneal lenses, blind species, straight lateral lobe. Antenna 1 (Fig. 9, 10 A): nearly equal to half of the body length. Peduncle with article 3 <article 1<article 2. Flagellum with 18 articles. Antenna 2 (Fig. 9, 10 B): Equal to antenna 1 in length. Peduncle segment 5> 4. Flagellum with 12 articles.

Mandible (Fig. 10 C): molar strong, palp very long, article 2> article 3, artcles 2, 3 bear long setae, article 3 with a long apical seta. Lower lip bilobate (Fig. 10 F). Maxilla 1 (Fig. 10 E): inner plate conical, outer plate with spine teeth distally, last article of palp ended with some setae and 5 strong teeth. Maxilla 2 (Fig. 10 G): the two plates are subequal in length and apically densely setose. Maxilliped (Fig. 10 D): inner plate sub-rectangular with short setae on the lateral and distal part. Internal margin of the outer plate with numerous long setae and strong teeth. Palp elongate, longer than outer plate, articles 2 and 3 with long setae, article 3 distally enlarged, dactylus elongate slender with 4 setae at the inferior margin.

Pereon: small setae on the posterodorsal part of segment 6 and 7 (Fig. 9). Gnathopod 1 (Fig. 11A): longer than gnathopod 2. Coxa 1 as long as basis, distal margin rounded and fringed with long setae. Basis a little longer than carpus+propodus, setose. Merus, carpus and propodus bears long setae, dactylus curved with 5 short setae. Gnathopod 2 (Fig. 11B): Coxa 2 shorter than basis, triangular, distal margin pointed. Basis long with long setae, egal to merus+carpus+propodus. Carpus longer than propodus, roughtly rectangular with long setae mainly on the inferior margin. Propodus roughtly rectangular. Dactylus curved and ornamed with 5 setae. Pereopod 3 (Fig. 11C): Coxa 3 triangular, distal margin pointed. Basis rectangular, basis = ischium + merus + carpus, the margins of the different articles except dactylus, bearing long setae. Dactylus strong, curved, very long, longer than propodus. Pereopod 4 (Fig. 11D): Coxa 4 pointed, shorter and wider than coxa 3, posteriorly excavate, ventral margin straight with one seta on the distal part. Basis rectangular, longer than ischium + merus + carpus. Dactylus curved, as long as propodus. Long setae are present on the margins of all articles except dactylus. Pereopod 5 (Fig. 11E): coxa 5 bilobate, posterior margin rounded. Basis oval anterior margin fringed with short setae. Carpus sub-rectangular with a small postero-distal lobe, posterior and distal margins ornamented with 4 rows of spines. Propodus rectangular, longer than carpus. Dactylus very strong and curved. Pereopod 6 (Fig. 11F): Coxa 6 triangular, distal edge rounded. Basis pyriform with a small indentation at the posterodistal corner. Carpus rectangular with a small distal lobe, posterior and distal margins ornamented with 3 rows of spines. Pereopod 7 (Fig. 12A, B): coxa rectangular, distally rounded. Basis broad, width / length = 1/2, anterior and posterior margins with numerous long setae. Ischium quadrangular with 2 small strong spines on the posterior margin. Merus quadrangular but longer than width. Carpus shorter and narrower of merus with inferior corner elongate. Propodus and dactylus short.

Pleon: Segment 1 and 2 with short setae (Fig. 9). Epimeral plate 1: short, ventral margin rounded. Epimeral plate 2 (Fig. 12 F): Rounded distal margin with 2 setae. Epimeral plate 3 (Fig. 12 F): anterior margin straight, anteroventral corner round, vental margin slightly convex, postero-ventral corner rounded, posterior margin convex with 4 setae.

Urosome (Fig. 9): segment 1 with a small hump anteriorly at a high rounded dorsal carina. Uropod 1 (Fig. 12C): long, the rami unequal and slightly curved, rami inermous, peduncle longer than rami (peduncle/outer ramus/inner ramous = 40/36/30), ornamented with only one seta at the inner distal corner. Uropod 2 (Fig. 12D): rami subequal, equal to peduncle, one spine on the distal inner corner of the peduncle and 3 on the edge of the inner ramus. Uropod 3 (Fig. 12E): peduncle short and strong, rami foliaceous, longer than peduncle, inner ramus with 2 strong spines, outer ramus with long apical setae and some ones on the margin.

Telson (Fig. 12 G): Triangular, rounded, slightly wide than long, cleft on 3/4 of the length, 2 or 3 long setae on each lobe.

Known distribution: North Atlantic Ocean; wide bathymetric range species. BIOFAR material, this study, bathymetric range: 600–1042 m; the nature of the bottom is indicated for only two samples: sand, gravel, cobbles and stones. Offshore Iceland, 913–1960 m (Dauvin and Bellan-Santini,1990). Faroe Islands: 600-1098 m (Dauvin 1996), Iceland one station 1392 m (Bellan-Santini and Dauvin, 1997), south and west of Iceland, 13 stations from 285 to 1963 m (Dauvin et al., 2012).

Taxonomic remarks. H. vallifera belongs to the sub-group of blind species with a narrow Pereopod 7 basis and without dorsal tuft setae which includes six other species: H. abyssorum, H. similis, H. lodo, H. dauvini, H. bjarnii, and H. faroensis. It differs from these species by having:

— Dorsal side of pereon and urosome carinate.

— Coxa 1 rectangular with the distal margin rounded.

— Coxa 2 triangular, with the distal margin pointed.