Epimeria (Pseudepimeria) oxicarinata Coleman, 1990

d’Acoz, Cédric d’Udekem & Verheye, Marie L., 2017, Epimeria of the Southern Ocean with notes on their relatives (Crustacea, Amphipoda, Eusiroidea), European Journal of Taxonomy 359, pp. 1-553 : 135-137

Epimeria (Pseudepimeria) oxicarinata Coleman, 1990

Figs 291–292

Epimeria oxicarinata Coleman, 1990b: 158–166 , 175, 177–178, pls 5–9, 17.

“Eine neue, noch unbekannte Epimeria -Art” – Andres in Sieg & Wägele 1990: pl. 8, lower photograph.

Epimeria oxicarinata – De Broyer & Klages 1991: 166 (key). — Coleman 2007: 46, fig. 23a–b, colour pl. 2 fig. g, map 13 (rhomb). — Lörz & Coleman 2009: unnumbered photograph on p. 17. — Rauschert & Arntz 2015: 61, pl. 54, unnumbered photograph.

Epimeria oxycarinata – Wakabara & Serejo 1999: 641 (key). — Barnes 2007: 5, pl. 5, unnumbered photograph (misspelling).

‘Clade H grandirostris-pulchra-oxicarinata complex - OX’ – Verheye et al. 2016a, supplement: 5 (online).

Material examined

RV Polarstern cruises:

SOUTHERN OCEAN: 1 spec., cruise PS14, ANT-VII/4, EPOS leg 3, stn 211, Elephant Island, 60°59.8ʹ S, 55°12.1ʹ W to 60°59.3ʹ S, to 55°10.5ʹ W, 207–213 m, bottom trawl, 15 Jan. 1989, coll. C. De Broyer ( RBINS, INV. 132945); 1 spec., cruise PS48, ANT-XV/3, EASIZ II, stn 353, north of Nelson Island, 61°59.4ʹ S, 59°14.4ʹ W to 61°58.2ʹ S, 59°14.3ʹ W, 129–132 m, Agassiz trawl, 20 Mar. 1998, coll. C. De Broyer ( RBINS, INV. 132723); 1 spec., cruise PS69, ANT-XXIII/8, stn 605-3, Elephant Island, 61°20.33ʹ S, 55°31.53ʹ W to 61°20.35ʹ S, 55°30.18ʹ W, 148–154 m, Agassiz trawl, 20 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert ( RBINS, INV. 122483) [extraction N8; Genbank nr, COI: KU870892 ]; 1 ♀, cruise PS69, ANT-XXIII/8, stn 605-5, Elephant Island, 61°20.27ʹ S, 55°30.92ʹ W to 61°20.37ʹ S, 55°28.99ʹ W, 131–152 m, 20 Dec. 2006, Agassiz trawl, coll. C. d’Udekem d’Acoz and H. Robert ( RBINS, INV. 122482); 8 specs, cruise PS69, ANT-XXIII/8, stn 614-3/4/5, Elephant Island, 60°52.37ʹ S, 55°29.80ʹ W to 60°52.71ʹ S, 55°27.83ʹ W, 248–265 m, a lot of epifauna, Rauschert dredge and Agassiz trawl, 22 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert ( RBINS, INV. 122517); 1 spec., PS69, ANT-XXIII/8, stn 614-3/4/5, Elephant Island, 60°52.37ʹ S, 55°29.80ʹ W to 60°52.71ʹ S, 55°27.83ʹ W, 248–265 m, a lot of epifauna, Rauschert dredge and Agassiz trawl, 22 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert (MNHN-IU-2014-7338, removed from RBINS, INV. 122517); 1 spec., cruise PS69, ANT-XXIII/8, stn 614-3/4/5, Elephant Island, 60°52.37ʹ S, 55°29.80ʹ W to 60°52.71ʹ S, 55°27.83ʹ W, 248–265 m, a lot of epifauna, Rauschert dredge and Agassiz trawl, 22 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert ( RBINS, INV. 132942); 1 spec., cruise PS69, ANT- XXIII/8, stn 614-3/4/5, Elephant Island, 60°52.37ʹ S, 55°29.80ʹ W to 60°52.71ʹ S, 55°27.83ʹ W, 248– 265 m, a lot of epifauna, Rauschert dredge and Agassiz trawl, 22 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert ( RBINS, INV. 132972); 1 spec., cruise PS69, ANT-XXIII/8, stn 614-3/4/5, Elephant Island, 60°52.37ʹ S, 55°29.80ʹ W to 60°52.71ʹ S, 55°27.83ʹ W, 248–265 m, a lot of epifauna, Rauschert dredge and Agassiz trawl, 22 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert ( RBINS, INV. 122468) [extraction N7; Genbank nr, COI: KU870891 ]; 1 spec., cruise PS69, ANT-XXIII/8, stn 614- 3/4/5, Elephant Island, 60°52.37ʹ S, 55°29.80ʹ W to 60°52.71ʹ S, 55°27.83ʹ W, 248–265 m, a lot of epifauna, Rauschert dredge and Agassiz trawl, 22 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert ( RBINS, INV. 122472); 1 spec., cruise PS69, ANT-XXIII/8, stn 614-3, Elephant Island, 60°52.37ʹ S, 55°29.80ʹ W to 60°52.71ʹ S, 55°27.83ʹ W, 248–265 m, Agassiz trawl, 22 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert ( RBINS, INV. 122521); 1 spec., cruise PS69, ANT-XXIII/8, stn 639-1, Elephant Island, 61°10.27ʹ S, 55°56.52ʹ W to 61°11.12ʹ S, 55°53.03ʹ W, 127–128 m, bottom trawl, 26 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert ( RBINS, INV. 122518); 2 specs, cruise PS69, ANT-XXIII/8, stn 644-1, Elephant Island, 61°03.19ʹ S, 55°54.36ʹ W to 61°01.78ʹ S, 55°51.83ʹ W, 150–187 m, bottom trawl, 27 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert ( RBINS, INV. 122522).

Description

ROSTRUM. Long, overreaching tip of peduncle of antenna 1; in lateral view, regularly curved, forming a distinct obtuse angle with head, ventrally very weakly concave, tip scarcely curving downwards; in frontal view, fairly broad, with weakly convex borders, with acute tip.

EYE. Medium-sized, conical.

PEREION–PLEOSOME TOOTH PATTERN. Pereionite 1 with very long, narrow, sharp mid-dorsal tooth arching forward (anterior border strongly concave, posterior border strongly convex), with pair of long, sharp, dorsolateral teeth, and pair of small ventrolateral teeth; pereionite 2 much narrower than pereionites 1 and 3, with small, narrow and sharp tooth pointing upwards (5 × shorter than mid-dorsal tooth of pereionites 1 and 3), with pair of small dorsolateral teeth, and pair of small ventrolateral teeth; pereionites 3–7 with very long, very narrow, very sharp mid-dorsal tooth of which the anterior and the posterior borders are nearly straight, with pair of large and sharp dorsolateral teeth, and pair of small ventrolateral teeth; pleonites 1–2 with very long, very narrow, very sharp mid-dorsal tooth of which the anterior and the posterior borders are nearly straight, with pair of large acute dorsolateral teeth and very small denticles; pleonite 3 very long, very narrow, very sharp mid-dorsal tooth of which the anterior and the posterior borders are nearly straight, with about 5 pairs of dorsolateral teeth, of which 2 are large and sharp and the others small to very small.

COXAE 1–3. Strongly carinate and distally sharp.

COXA 4. Anterodorsal border weakly but distinctly concave; anteroventral border with deep notch, with distal part nearly straight; anterior angle produced into a large and sharp tooth pointing downwards; ventral tooth long, narrow and sharp, directed ventrally (scarcely arching backwards); lateral carina with long and sharp tooth projecting laterally; in lateral view, inner corner of carina forming a distinct obtuse angle; in lateral view posteroventral border of coxa deeply concave; the concavity is rounded.

COXA 5. In dorsal view, with very large, narrowly triangular, carinate, lateral tooth, of which the anterior and the posterior borders point obliquely backwards; tip of carina sharp.

COXA 6. With narrowly triangular carinate lateral tooth of which the anterior border (which is convex) and the posterior border (which is concave) points obliquely backwards (character to be examined in dorsal view); tip of carina very sharp.

COXA 7. With ventral + posterior borders forming a regular curve, with small lateral tooth.

EPIMERAL PLATES 1–3. Plate 1 with posteroventral angle angulate, with distinct lateral carina and 2 lateral teeth; plate 2 with posteroventral angle sharply angulate (forming a distinct sharp triangular tooth), with distinct lateral carina and 2 lateral teeth; plate 3 with posteroventral angle produced into a very long tooth, with distinct lateral carina and 1 lateral tooth, with posterior margin weakly convex.

UROSOME TOOTH PATTERN. Urosomite 1 with sharp narrow mid-dorsal tooth pointing upwards, with pair of lateral denticles at the same level as mid-dorsal tooth; urosomite 2 with 2 pairs of small posterior

dorsolateral teeth pointing upwards (a very small triangular one followed by a longer styliform one); urosomite 3 with pair of mid-sized posterior dorsolateral teeth pointing upwards.

TELSON. Cleft on 0.4; tips of lobes sharp, notch V-shaped.

PEDUNCLE OF ANTENNA 1. Article 1 with anterior border weakly concave, with well-developed anterior and posterior tooth; article 2 with medium-sized lateral triangular tooth; article 3 with weak ventral tooth.

GNATHOPODS 1–2. Very small, achelate; carpus and propodus of medium stoutness in gnathopod 1 (propodus tapering), of fairly narrow in gnathopod 2; dactylus of gnathopod 2 fairly broad and posteriorly slightly convex.

PEREIOPODS 3–4. Merus, carpus and propodus extremely broad and short; dactylus fairly large, strongly curved on both sides, clasping.

PEREIOPODS 5–6. Basis of normal width, with posteroproximal process sharply triangular and strongly protruding, with posterodistal tooth large and sharp; merus, carpus and propodus extremely broad and short; dactylus fairly large, strongly curved on both sides, clasping.

PEREIOPOD 7. Basis of medium-width; posterior border distinctly diverging from axis of basis in proximal 0.75; at this level it forms a triangular tooth (i.e., blunt-tipped acute, nearly straight angle), which is followed by a deep concavity; this concavity form a broadly rounded curve; the posterodistal corner is produced into a long narrow tooth pointing obliquely backwards; merus, carpus and propodus extremely broad and short; dactylus fairly large, strongly curved on both sides, clasping.

Colour pattern

Transversally striped of white, red and orange.

Body length

Up to 26 mm.

Distribution

Elephant Island, 127–267 m ( Coleman 2007; present data), Drake Passage: north of Nelson Island (present data).

Biology

Coleman (1990a) found thecate hydrozoans (cf. Oswaldella antarctica (Jäderholm, 1904)) in the stomachs of several E. oxicarinata specimens. A photograph of the species clinging onto a thecate hydrozoan with an long strong stem and thin lateral branches was published by Coleman (2007). So it is likely that E. oxicarinata is a hydroid-associated and hydroid-feeding species.

Remarks

There is an unconfirmed record of E. oxicarinata from the eastern shelf of the Weddell Sea ( Klages 1991; De Broyer et al. 2007), but this might be a misidentification, possibly a confusion with E. cyrano sp. nov., which is also a very spiny, albeit very different in other morphological characters. The collection station of the specimen of Epimeria oxicarinata illustrated by Rauchert & Arntz (2015) was mentioned in an early draft of their book accessed by the authors: ANT-XV/3 stn 355. This corresponds to 61°59.8ʹ S, 59°14.8ʹ W to 62°00.1ʹ S, 59°14.8ʹ W (north of Nelson Island), 128– 130 m.

Figures

Fig. 291. Epimeria (Pseudepimeria) oxicarinata Coleman, 1990, adult ♀, Elephant Island, ANT- XXIII/8, stn 605-5, RBINS, INV. 122482, colour in life. A. Lateral view. B. Dorsal view.

Fig. 292. Epimeria (Pseudepimeria) oxicarinata Coleman, 1990, medium-sized specimen, sex undetermined, Elephant Island, stn 614-3/4/5, RBINS, INV. 132942. A. Lateral habitus. B. Dorsal habitus. C. Frontal habitus.