Haploops dauvini, Peart, Rachael A., 2018

Peart, Rachael A., 2018, Ampeliscidae (Crustacea, Amphipoda) from the IceAGE expeditions, ZooKeys 731, pp. 145-173 : 154-160

Haploops dauvini sp. n. Figures 5, 6, 7

Type material.

Holotype, female, 7 mm, ZMH K-47038, station IceAGE 2, 868-3, Norwegian Channel, 000°15.51'E - 000°15.86'E, 62°09.14'N - 62°10.30'N, 587.4 - 614.4 m, POS-456, from the supranet bucket of EBS, 25.07.2013. Paratypes: ZMH K-47039, female 6 mm; NIWA 123641, female, 7 mm, same collection data as holotype.

Additional material examined.

ZMH K-47042, ZMH K-47043, 8 specimens, station IceAGE 2, 879-5, Faroe Island Ridge (middle), 008°34.32'W - 008°36.22'W, 63°06.10'N - 63°05.62'N, 500.6 - 510.9 m, POS-456, 31.07.2013. ZMH K-47040, 1 specimen, station IceAGE 2, 880-2, Faroe Island Ridge (middle), 008°09.42'W - 008°11.22'W, 63°23.36'N - 63°24.62'N, 686 - 687.4 m, POS-456, 31.07.2013.

Type locality.

Norwegian Channel, North Atlantic Ocean.

Etymology.

This species is named for Dr Jean-Claude Dauvin, whose extensive work on the family Ampeliscidae was invaluable for the description of this species.

Diagnosis.

Eyes absent. Head anterior margin straight. Antenna 1 article 1 almost half the length of article 2. Antenna 2 peduncular article 4 subequal in length to article 5. Gnathopod 1 carpus subequal in length to the propodus. Gnathopods and pereopods without setal fringe. Pereopod 4 coxa broad. Pereopod 5 basis almost circular. Pereopod 7 basis narrow. Uropod 1 rami subequal in length. Telson with 1 distal robust seta per lobe.

Description.

Based on holotype adult female, 7 mm in length.

Both pereon and pleon without dorsal setae. Head almost as deep as long, rostrum absent, anterior margin straight and almost perpendicular to dorsal margin. Corneal lenses absent. Antenna 1 as long as antenna 2, close to half body length; peduncular article 1 shorter than article 2 (0.6 ×), article 2 longer than article 3 (3 ×), article 3 shorter than article 1 (0.5 ×); flagellum short with 16 articles, fringed ventrally with long, weakly plumose setae. Antenna 2 close to half the body length; peduncular article 4 approximately subequal to article 5 (0.9 ×); flagellum with 15 articles; peduncle and flagellum fringed with long, weakly plumose setae.

Upper lip distally notched, lightly setose. Mandible molar well developed and triturating, with 7 plumose robust setae in the accessory setal row; palp long, article 2 shorter than article 3 (0.85 ×); article 2 weakly setose, article 3 strongly setose with plumose setae. Lower Lip with inner and outer lobe, inner half the height of the outer. Maxilla 1 inner plate with 1 apical strong plumose seta and 4 accessory simple facial setae; palp with two articles, second article reaching past length of outer plate, with 4 robust setae distally and four slender, plumose facial setae. Maxilla 2 plates of similar widths, both with long plumose setae. Maxilliped inner plate elongated with a rounded tip with one short robust seta and nine long plumose slender facial setae; outer plate ovoid reaching to ¾ length of palp article 2, inner lateral margin with robust setae tending to long plumose setae distally; palp article 4 longer than article 3, and inserted subterminally, inner margin setose.

Pereon. Gnathopod 1 coxa roughly teardrop shape, expanded and rounded distally. In situ, reaching to level of anterior margin of head, ventral margin broadly and evenly rounded with fringe of long plumose setae, scattered setae medially; basis shorter than coxa, same length as carpus and propodus together, lateral margins and medially fringed with long plumose setae and occasional short non-plumose setae; merus slightly lobate with long plumose setae on posterior margin; carpus longer than merus, slightly longer than propodus (1.15 ×), with slight rounded posterior lobe, posterior margin bearing many long, plumose slender setae; propodus ovoid, subchelate, posterior margin slightly serrate, strongly setose on both posterior and anterior margin; dactylus long and curved, inner margin setose, reaching to half of length of propodus. Gnathopod 2 coxa 2/3 length of coxa 1, narrowing slightly distally, ventral margin rounded with sparse plumose setae; basis longer than coxa, similar length to carpus and propodus combined, lateral margins with long plumose slender setae; merus non-lobate; carpus longer than merus and longer than propodus (1.6 ×), non-lobate, long plumose setae on both posterior and anterior margins (more dense on posterior margin); propodus ovoid, subchelate, palm not strongly defined, long, plumose setae on both anterior and posterior margins; dactylus shorter than propodus (0.6 ×), with a setose inner margin.

Pereopod 3 coxa similar in length to coxa 2, ventral margin rounded with sparse long plumose setae; basis longer than coxa, just shorter than merus + carpus + propodus, lateral margins with long, plumose setae; merus shorter than basis, longer than carpus and propodus combined, sparsely setose on both posterior and anterior margins, not inflated; carpus short with long plumose setae on the posterior margin only; propodus longer than carpus, long, plumose setae on anterior margin plus two on the posterior margin, posterior margin straight (not concave or convex); dactylus shorter than carpus and propodus combined (longer than propodus individually), not setose, straight. Pereopod 4 coxa broad with rounded extended posterior lobe, ventral margin rounded (no acute corners) with sparse, plumose setae; basis longer than coxa, fringed laterally with long, plumose setae on both margins, shorter than merus + carpus + propodus; merus narrow, longer than carpus and propodus combined, long plumose setae only at distal end of article; carpus short with posterior, long, plumose setae only; propodus longer than carpus with sparse (2 on anterior and 1 on posterior) plumose setae; dactylus shorter than propodus, straight and without setae.

Pereopod 5 basis broadly rounded, almost circular, anterior margin with a few short setae; distal articles broken off. Pereopod 6 basis almost circular, not as broad as basis 5, anterior margin with sparse small setae, posterior margin rounded; ischium with acute posterior lobe; merus same length as ischium, weakly setose; carpus longer than merus, slightly shorter than propodus (0.85 × not including posterior lobe), anterior margin with two weak robust setae, posterior margin with two rows of stout robust setae (2 and 4), and extended to form a lobe bearing 6 strong, robust setae increasing in length laterally; propodus narrower than carpus, anterior margin with two weak robust setae, posterior margin without robust setae, anterior margin produced slightly to form a weakly setose lobe; dactylus strongly curved and smooth, much shorter than propodus. Pereopod 7 basis moderately narrow (length without lobe /width = 2.0 ×), anterior and posterior margins slightly concave, medial surface with numerous long, plumose setae, posterior-distal lobe narrow, rounded and deflected, reaching to ¾ length of ischium, with a few marginal setae; ischium without anterodistal robust setae; merus subrectangular, longer than ischium (1.8 ×), subequal in length to carpus, anterior margin with one marginal and one distal robust seta, not lobate, posterior margin not lobate with two marginal and one distal robust seta; carpus subovoid, broad (width/length = 0.75 ×), anterior margin slightly lobate distally, with three marginal robust setae, posterior margin not lobate with two long marginal robust setae and one distal robust seta; propodus narrow, less than half the length of the carpus, no setae; dactylus broken off.

Pleon smooth. Epimeron 1 posteroventral corner broadly rounded, no tooth. Epimeron 2 posteroventral corner broadly rounded, no tooth. Epimeron 3 subquadrate, no tooth and no setae, dorsal margin with sparse, very short setae. Urosomite 1 slightly raised to form a small rounded carina, dorsal margin bearing a few very short setae. Urosomites 2-3 fused.

Uropod 1, in situ, reaching one third of the length of uropod 2 rami; peduncle shorter than rami, outer margin with two robust setae, inner margin with three slender setae, one strong robust seta medio-distally; rami subequal in length, both curved and gently tapering to a subacute tip; outer ramus without setae; inner ramus with two robust setae. Uropod 2 peduncle longer than rami, inner margin with 2 slender setae and two long robust setae distally; rami subequal in length, narrow tapering to a rounded tip; outer ramus with one marginal robust seta; inner ramus with four marginal robust setae. Uropod 3 peduncle shorter than rami (0.65 ×), and without setae; rami long and narrow, even width along length, not tapering, truncated apically, subequal in length; outer ramus two robust setae distally, long plumose setae on distal half of each margin; inner ramus with two strong robust setae on outer margin and one robust seta distally, plumose setae on distal part of inner margin, hair-like fringe on proximal half of outer margin. Telson slightly longer than wide (1.2 ×), cleft to 68%, each lobe apically rounded subquadrately; each lobe with two slender dorsal setae, one apical slender setae and one apical robust seta.

Male. No males availables in the samples.

Remarks.

Of the blind species in Haploops , this species can be most closely allied to Haploops abyssorum Chevreux, 1908, H. lodo J.L. Barnard, 1961, H. similis Stephensen, 1925 and H. kaimmalkai (current work). The similarities between these species are due to the lack of eyes and a narrow pereopod 7 basis. The differences between the five species are shown in table 2.