Prometopa cedrici Krapp-Schickel 2011
- Dataset
- New Antarctic stenothoids sensu lato (Amphipoda, Crustacea)
- Rank
- SPECIES
- Published in
- Krapp-Schickel, Traudl (2011): New Antarctic stenothoids sensu lato (Amphipoda, Crustacea). European Journal of Taxonomy 2: 1-17, DOI: 10.5852/ejt.2011.2
Classification
- kingdom
- Animalia
- phylum
- Arthropoda
- class
- Malacostraca
- order
- Amphipoda
- family
- Stenothoidae
- genus
- Prometopa
- species
- Prometopa cedrici
description
Description HABITUS. Dorsal outline spiky from peraeonite 1 - 5, the next four body segments reinforced dorsally, appearing ' double folded', with rounded outline. Suture between urosomites not clear. HEAD. A 1 subequal to A 2. A 1 peduncle art. 1> art. 2, ratio art. 2: art. 3 = 2; art. 1 ordinary, without nasiform process; flagellum with 14 arts. A 2 art. 4> art. 5, flagellum with 8 - 9 arts. Mouthparts: Md molar small; palp longer than Md body, ratio art. 2: art. 3 = about 3, sparse and regular setation on art. 2, only one distal seta on art. 3. Mx 1 palp with 2 arts. Mx 2 IP about half length of OP, both with long setae distally, next to them some short ones. GNATHOPODS. Gn 1 much smaller than Gn 2. Cx 1 semicircularly rounded distally. Basis robust and distally widening, on anterior margin long and short setae, on posterior one only short setae. Ischium longer than wide, with long setae distally. Merus distoposteriorly lengthened and beset with short and stiff setae, also two long setae and two spines distally. Carpus triangular, beset with long setae on anterior and posterior margin. Propodus 3 - 4 times as long as wide, on all margins some long setae, palm weakly rounded without any palmar corner, but defined by 5 spines. Gn 2 strong. Cx 2 tongue-shaped, about twice as long as wide, with nearly parallel margins. Basis 3.5 times longer than wide, anterior margin densely beset with many fine setae, only 3 setae on posterior margin. Ischium somewhat longer than wide, like merus with few setae. Carpus triangular, shorter than wide, distally lobed with long distal and shorter marginal setae. Propodus subrectangular, distally a bit wider than proximally, with irregular setae anteriorly and posteriorly; palmar corner nearly rectangular, with prominent robust tooth, palm with U-shaped excavation medially and many small incisions. Dactylus short and strong, with many short setae on the inner side. PERAEOPODS. P 3 slender. Cx 3 similar to Cx 2, about 2.5 times as long as wide, with parallel margins. Basis and ischium about twice as wide as propodus and carpus, merus acutely lengthened anterodistally. Dactylus strong. P 4 clearly stronger than P 3: Cx 4 subtrapezoidal, about as long as wide. Basis and ischium similar to P 3. Merus much wider than in P 3, acutely lengthened anterodistally. Carpus distad widening, with short spines. Propodus with spines and setae. Dactylus distally bifid. P 5 similar to P 4, strong and richly beset with spines and setae on both margins; basis rectangular, merus posteriorly lengthened, reaching about half length of carpus; dactylus robust, bifid. P 6 similar to P 5 but basis widened, posterior margin straight, merus posteriorly reaching end of carpus. P 7 similar to P 6 but basis posteriorly much more widened, margin rounded. PLEON. Pl 1 - 3 and Us 1 dorsally thickened, with ' double pleat'. Ep 1 tongue-shaped lengthened posterodistally. Ep 2, 3 with small upturned tooth posterodistally. Us 2 much narrower than Us 1 or Us 3. U 1 peduncle much longer than subequal rami, with small spines. U 2 peduncle longer than longer ramus, ratio of length of rami about 3: 2; with small spines. U 3 very strong, peduncle shorter than in U 2, but about twice as wide, with strong spines; ramus two-articulated, articles about the same length and also with strong spines on first article. TELSON. Triangular, flappable, about 1.7 times longer than wide, with 4 - 5 strong spines marginally.
description
Figs 1 - 6
discussion
Remarks This genus seems quite closely related to the following one, in partly sharing also a nasiform thickened A 1 peduncle and varying humps dorsally. But the telson is flappable and horizontally inserted, as in ordinary stenothoids, and the propodi of the gnathopods are very different in size and shape. For comparing this new species with other members of the genus, see key:
etymology
Etymology Dedicated to Cédric d'Udekem d'Acoz (Brussels), extremely careful taxonomist for amphipods and decapods.
materials_examined
Holotype ♂? 4.5 mm, fully dissected and mounted in slides in Faure's liquid; RBINS, I. G. 31071 2 slides: IG 31071 / INV 83816 A and IG 31071 / INV 83816 B (Museum Brussels). R / V Polarstern, cruise ANTARKTIS- XXIII / 8, Larsen B area, station 702 - 9 B _ South 65 ° 57.85 ' S 60 ° 28.42 ' W to 65 ° 57.42 ' S 60 ° 28.12 ' W, 12 / 01 / 2007, 215 - 221 m, hard bottom with a lot of hydrocorals; gear: Agassiz trawl. Paratype ♀, 4.8 mm, partly dissected, dissected parts mounted on 2 slides, registration numbers: RBINS, IG 31071 / INV 83816 B and INV 83816 C (Museum Brussels), same locality as above.