Bathya brevicarpus, Wang & Zhu & Sha & Ren, 2020

Wang, Yan-Rong, Zhu, Chao-Dong, Sha, Zhong-Li & Ren, Xian-Qiu, 2020, Bathya brevicarpus gen. et sp. nov. (Amphipoda: Senticaudata: Calliopiidae), from hydrothermal vents, Okinawa Trough, North-west Pacific, European Journal of Taxonomy 693, pp. 1-12 : 4-7

Bathya brevicarpus gen. et sp. nov.

urn:lsid:zoobank.org:act:2A8520B1-C0C6-4BAB-9C8D-A7DFB57B111D

Figs 1–2

Diagnosis

As for the genus.

Etymology

The new species name contains the Latin ‘ brev ’ (= short), referring to the carpus of the gnathopods 1 and 2 being shorter than the propodus.

Material examined

Holotype

NORTH-WEST PACIFIC • ♂, 5.6 mm, dissected; Okinawa Trough; depth 996.9 m; 17 Apr. 2014; RY0108, ROV-4; MBM 286556 .

Description

BODY. Dorsally smooth.

HEAD. Nearly subequal in length to pereonites 1 and 2 combined, rostrum small, anterior lobe rounded, lower margin with large and acute projecting tooth anterodistally; eyes present, but not pigmented, hardly visible in ethanol material.

ANTENNA. Antenna 1 longer than antenna 2; peduncular article 1 wider and longer than article 2; article 2 less than twice longer than article 3; article 3 not produced apicoventrally; primary flagellum 23-articulate, few very thin and short setae scattered along flagellum; accessory flagellum absent. Antenna 2 slender than antenna 1, peduncular article 5 distinctly longer than article 4; flagellum longer than peduncle, 28-articulate.

MOUTH PARTS. Upper lip and lower lip broken. Mandible symmetrical, with incisor dentate, bearing 7 teeth; lacinia mobilis dentate, with 8 teeth; with 12 accessory spines; molar well developed, columnar, triturative; palp elongate, slender, 3-articulate, article 3 longer than article 2, ventral face bearing short stout setae. Maxilla 1 with inner plate bearing one apical stout seta; palp 2-articulate, article 2 longer than article 1, bearing 6 small robust and three long simple setae. Maxilla 2 inner plate slightly narrower than outer, only bearing sparse slender subapical marginal setae, without oblique row of slender setae.

GNATHOPODS. Coxae 1–4 longer than broad, coxa 4 broader than coxae 1–3. Gnathopod 1 subchelate, slightly smaller than gnathopod 2; coxa weakly produced anteroventrally; merus subrectangular, bearing row of slender setae along distal margin; carpus shorter than propodus, cup-shaped, with dense long slender setae on posterior margin; propodus suboval, palm acute, posterior margin with robust and short simple setae; dactylus evenly tapering, with acute tip. Gnathopod 2 similar in shape to ganthopod 1; coxa subrectangular, subequal in length to coxa 1, anterior margin slightly convex; carpus distinctly shorter than propodus, weakly lobed; propodus with tooth-like protruded sub-distally, bearing short simple and robust setae along posterior margin; dactylus with acute tip, evenly tapering.

PEREOPODS. Pereopod 3 (distal three articles broken in holotype) slender, merus bearing large produced lobe anterodistally. Pereopod 4 similar to pereopod 3, but coxa much broader. Pereopod 5 slightly longer than pereopod 7, coxa bilobate, anterior lobe smaller than posterior lobe; merus broader than distal three articles, with posterodistal strongly produced as lobe, anterior margin with 4+ groups of 2–3 robust setae; propodus 1.4 times longer than carpus, anterior margin bearing 8 groups of 2–3 bifid robust setae; dactylus slender, with acute tip, evenly tapering, 0.7 length of propodus, with small nail. Pereopod 6 (distal three articles broken in holotype) gill smaller than that of pereopod 5; coxa bilobate, anterior lobe much smaller than posterior lobe; basis slight longer than that of pereopod 5. Pereopod 7 coxa unilobate, rounded; basis broader than that of pereopods 5 and 6, anterior margin bearing robust setae; propodus subequal in length to carpus; dactylus half-length of propodus, with small acute nail.

GILLS. Present on coxae 2–6, small, not pleated.

EPIMERAL PLATES 1 AND 3. Without tooth on posterior margin, postero-corner of epimeral 2 being subacute.

UROPODS. Uropod 1 overreaching distal end of uropod 2, without interramal spur; peduncle shorter than rami, with 19 marginal and one large distal robust setae; outer ramus shorter than inner ramus, but subequal in broad to inner, with 9 marginal and three distal robust setae; inner ramus with 14 marginal and 3 distal robust setae. Uropod 2 peduncle distinctly shorter than rami, with 5 marginal and two distal robust setae; outer ramus 0.6 times shorter than inner ramus, with 10 marginal and three distal robust setae; inner ramus with 15 marginal and three distal robust setae. Uropod 3 shorter than uropod 2, peduncle shorter than rami, with one robust seta distally; outer ramus 0.55 times shorter than inner ramus, with 7 marginal robust setae; inner ramus with 15 marginal robust setae.

TELSON. Entire, longer than broad (length 1.7 times as long as width at base), distal margin convex.

Figures

Fig. 1. Bathya brevicarpus gen. et sp. nov., holotype, ♂ (MBM 286556).

Fig. 2. Bathya brevicarpus gen. et sp. nov., holotype, ♂ (MBM 286556).