Epimeria (Hoplepimeria) heldi, d’Acoz & Verheye, 2017

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 : 83-84

Epimeria (Hoplepimeria) heldi subgen. nov. Coleman, 1998

Epimeria heldi Coleman, 1998a: 17–25 , figs 1–5.

Epimeria heldi – Wakabara & Serejo 1999: 642 (key). — Coleman 2007: 39, figs 18a–b, colour plate 1f, map 9 (rhomb).

Description

Description based on illustrations of Coleman (1998a).

ROSTRUM. Medium-sized, just overreaching tip of article 1 of peduncle of antenna 1, anteriorly weakly curved, ventrally straight, tip subacute in lateral view.

EYE. Very large, narrowly elliptic.

PEREION–PLEOSOME TOOTH PATTERN. Pereionites 1–5 smooth; pereionite 6 with weak mid-dorsal straight carina, pereionite 7 to pleonite 3 with low carina, each with median slight concavity and posterior corner bluntly angular; the carinae are strongly laterally compressed.

COXAE 1–3. Scarcely carinate and apically broadly rounded.

COXA 4. Anterodorsal border nearly straight (very slightly concave), anteroventral border weakly but distinctly concave, these two borders being joined by broad rounded angle (anterior corner), which is distinctly projecting forward; ventral corner forming a fairly narrow rounded projection; lateral carina present and projecting laterally (it appears as a low rounded lobe in dorsal view); at its deepest point the carina is very distant from the posteroventral border of the coxa; posteroventral border deeply concave.

COXA 5. Broad, with rounded lateral projection pointing laterally. In dorsal view, the lateral projection of coxa 4 and 5 looks like a mirror version of each other, the unit coxa 4 + coxa 5 forming a low concave structure on each side of the body.

COXA 6. Posteriorly broadly rounded, with very low projection arising from its surface (forming a very low rounded lobe in dorsal view).

COXA 7. Posterior and ventral border strongly convex; transition between these borders indistinct.

EPIMERAL PLATES 1–3. Posteroventral angle: rounded in plates 1–2, produced into a small tooth in plate 2 and into a medium-sized tooth in plate 3.

UROSOME TOOTH PATTERN. Urosomite 1 with low rounded dorsal process; urosomite 3 with dorsolateral borders straight, distally forming a rounded lobe.

TELSON. Cleft on 0.15; tips of lobes broadly rounded, notch broadly V-shaped.

GNATHOPODS 1–2. Carpus and propodus broad; propodus not expanding distally, palm distinct.

PEREIOPODS 5–7. Merus, carpus and propodus slender, dactylus medium-sized; basis of pereiopods 5–6 of normal width, with posteroproximal half forming a very low rounded projection; with posterodistal corner not produced; basis of pereiopod 7 narrow with posterior border straight, with posterodistal corner very bluntly angular, not projecting.

Colour pattern

Body and coxae whitish with a very faint dull purplish hue. Basis of pereiopods 5–7 pale dull purple. Antennae, other pereiopods, distal part of pereiopods 5–7 and tailfan dull brownish pink. Eyes pale yellow.

Body length

52 mm.

Distribution

Northwest of Elephant Island. Said to have been collected at 60°54.60ʹ S, 55°45.90ʹ W at 235 m depth (RV Polarstern, PS42, ANT-XIV/2, stn 31) ( Coleman 1998a). The coordinates of station 31 given by Kattner (1998) are slightly different and deeper: 60°53ʹ S, 55°47ʹ W to 60°54ʹ S, 55°57ʹ W, 443– 734 m. However, Coleman (pers. com.) informed us that the depth record given in his logbook is 230– 235 m.

Remarks

This highly characteristic species, which shares a number of character states with Epimeria georgiana and E. inermis , is presumably rare, as it was not found in the abundant Epimeria material from Elephant Island collected during the cruise ANT-XXIII/8. Epimeria heldi is tentatively assigned to the subgenus Hoplepimeria subgen. nov. based on morphological assessment only.