Epimeria (Hoplepimeria) rubrieques d'Acoz & Verheye 2017, subgen. nov.

Epimeria (Hoplepimeria) rubrieques subgen. nov. De Broyer & Klages, 1991

Figs 220–221

Epimeria rubrieques De Broyer & Klages, 1991: 159–166, figs 1–5.

Epimeria rubrieques – Klages 1991: 95–96, unnumbered figs. — Wakabara & Serejo 1999: 641 (key). — Chapelle 2002: 20, unnumbered photograph. — Barnes 2007: 5, plate 5, unnumbered photograph. — Lörz 2003: 85, 86, fig. 3. — Coleman 2007: 53, fig. 29a–b, colour plate 2a, map 7 (circle). — Lörz & Coleman 2009: unnumbered photograph on p. 17. — De Broyer & Jażdżewska 2014: 155, photo 1. — Rauschert & Arntz 2015: 62, pl. 55, unnumbered photographs.

Epimeria sp. 1 (nov.) – Klages 1988: 73, unnumbered fig.

Epimeria sp. nov. – Klages 1988: 75, 77, figs 15a–b.

‘Clade E georgiana-rimicarinata-rubriequies [sic] complex - RU’ – Verheye et al. 2016a, supplement: 4 (online).

Material examined

RV Polarstern cruises:

SOUTHERN OCEAN: 3 specs, in 3 different tubes, cruise PS10, ANT-V/3, station missing, eastern Weddell Sea, fixed on board [presumably after aquarium observations] on 20 Nov.1986,coll. C. De Broyer (RBINS, INV. 132732); 1 spec., cruise PS39, ANT-XIII/3, EASIZ I, stn 17, GSN 10, eastern Weddell Sea, 73°18.00ʹ S, 21°09.90ʹ W to 73°19.10ʹ S, 21°14.90ʹ W, 465–468 m, bottom trawl, specimen kept on board in aquarium, 16 Feb. 1996, coll. C. De Broyer and G. Chapelle (RBINS, INV. 132680); 1 spec., cruise PS48, ANT-XV/3, EASIZ II, stn 206, eastern Weddell Sea, 71°00.4ʹ S, 11°42.6ʹ W to 71°00.7ʹ S, 11°42.5ʹ W, 594–602 m, Agassiz trawl, 18 Feb. 1998, coll. C. De Broyer (RBINS, INV. 132990); 1 spec., cruise PS71, ANT-XXIV/2, ANDEEP-SYSTCO, stn 48-1, eastern Weddell Sea, 70°23.94ʹ S, 8°19.14ʹ W to 70°23.89ʹ S, 8°18.67ʹ W, 595–602 m, bryozoan bottom (exceptional bryozoan diversity), Rauschert dredge, 12 Jan. 2008, coll. H. Robert (RBINS, INV. 132943) [extraction K41; Genbank nr, COI: KU870874, 28S: KU759654]; 1 spec., fixed in formalin, cruise PS71, ANT-XXIV/2, ANDEEP- SYSTCO, stn 48-1, eastern Weddell Sea, 70°23.94ʹ S, 8°19.14ʹ W, to 70°23.89ʹ S, 8°18.67ʹ W, 595–602 m, bryozoan bottom (exceptional bryozoan diversity), Rauschert dredge, 12 Jan. 2008, coll. H. Robert (RBINS, INV. 132410); 1 small badly damaged spec., cruise PS77, ANT-XXVII/3, CAMBIO, stn 265- 2, eastern Weddell Sea, BENDEX area, 70°47.34ʹ S, 10°40.39ʹ W to 70°47.13ʹ S, 10°40.54ʹ W, depth not recorded [Google Earth depth range for these coordinates: 571–599 m (accessed 27 Sep. 2016)], Agassiz trawl, 22 Mar. 2011:, coll. Ch. Havermans and H. Robert (RBINS, INV. 132968) [extraction I5; Genbank nr, COI: KU870849, 28S: KU759626].

Diagnosis

ROSTRUM. Curved and very long, nearly reaching tip of article 2 of peduncle of antenna 1.

BODY SEGMENTS. All pereionites and pleonites with strong mid-dorsal tooth, without pair of dorsolateral teeth or projections (however there is a very faint trace of dorsolateral protrusions on posterior segments); pereionites without pair of ventrolateral teeth or projections; mid-dorsal tooth of pereionites nearly cylindrical, very long, with tip not acute; mid-dorsal tooth of pleonites 1–2 very narrowly triangular in lateral view, scarcely laterally compressed, with slight anterior notch; pleonite 3 with low rounded lobe followed by notch which is itself followed by a subacute broad triangular tooth.

COXA 4. Anteriorly produced into a blunt angle, strongly projecting forward, ventrally produced into a fairly narrow, subacute tooth, with posteroventral border very concave.

COXA 5. Produced into very long styliform tooth projecting obliquely backwards.

UROSOMITE 1. With rounded dorsal process.

PEDUNCLE OF ANTENNA 1. Not toothed.

GNATHOPODS 1–2. Carpus and propodus robust; propodus distally expanding, with palm oblique.

PEREIOPOD 5. Basis with posteroproximal tooth forming a blunt squared angle with the basis, with posterodistal corner not produced into a tooth.

PEREIOPOD 6. Basis with posteroproximal acutely triangular tooth pointing obliquely, with posterodistal corner not produced into a tooth.

PEREIOPOD 7. Basis with distinct notch forming a blunt obtuse angle on 0.8 of posterior border, with posterodistal corner not produced into a tooth.

Colour pattern

Body orange red. Rostrum laterally lined with white. Coxae 1–4 largely whitish. Posterior coxae and epimeral plates with diffuse whitish zones. Pereiopods largely whitish. Eyes orange.

Body length

Up to 70 mm.

Distribution

Eastern shelf of Weddell Sea (De Broyer et al. 2007), Davis Sea: Tressler Bank (Pyper 2010); 254– 1030 m (De Broyer et al. 2007).

Biology

Analyses of digestive tract contents revealed the following items: diatoms, sponge spicules, fragments of hydroids of the genus Staurotheca, spicules of Clavularia, crustacean remains (mainly amphipods), polychaete setae, and sclerites of holothurians (Sigmodota contorta (Ludwig, 1875) as Taeniogyrus contortus) (Dauby et al. 2001a). These authors conclude that E. rubrieques is rather an opportunistic feeder with both scavenging and predatory behaviour. Dauby et al. (2001b) stated that it is anopportunistic predator. Klages (1991) observed that the species is sometimes parasitized by cryptoniscin isopods. Klages (1991) also observed that hatchlings of E. rubrieques climb on the back of their mother and remain there for a short period of time.

Remarks

The collection data of the specimens illustrated on figure 29 by Coleman (2007) are: 73°12.39ʹ S, 20°46.24ʹ W (eastern shelf of the Weddell Sea), 650–710 m, 22.1.1985, leg. Wägele (Coleman pers. com.). The collection data of the “specimen 2” illustrated by Rauschert & Arntz (2015) were given in an early draft of their book accessed by us: ANT-XV/3 stn 222. Its coordinates are 70°49.1ʹ S, 10°39.2ʹ W 70°50.5ʹ S, 10°41.8ʹ W (eastern Weddell Sea) at 234– 385 m. The photograph of Pyper (2010: cover art of the Australian Antarctic Magazine, as “amphipod”) shows E. rubrieques. That specimen came from the Tressler bank, which considerably extends eastwards the distribution of the species.