Epimeria (Hoplepimeria) angelikae, 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 : 74-76

Epimeria (Hoplepimeria) angelikae subgen. nov. Lörz & Linse in Lörz et al., 2011

Figs 132–137

Epimeria angelikae Lörz & Linse in Lörz et al., 2011: 6 , figs 6, 7, 8, 9, 10, 11, 12.1, 12.2.

‘ Epimeria inermis 3’ – Rauschert & Arntz 2015: 61, pl. 54. ‘Clade E georgiana-rimicarinata-rubriequies [sic] complex - GE5’ – Verheye et al. 2016a, supplement: 4 (online).

non Epimeria inermis Walker, 1903: 54 , pl. 10 fig. 69.

Material examined

RV Polarstern cruises:

SOUTHERN OCEAN: 1 spec., exuvia, cruise PS39, ANT-XIII/3, EASIZ I, eastern Weddell Sea, no station, specimen kept in aquarium, 26 Mar. 1996, coll. C. De Broyer and G. Chapelle ( RBINS, INV. 132682); 2 specs, cruise PS48,ANT-XV/3, EASIZ II, stn 95, eastern Weddell Sea, 73°33.5ʹ S, 22°15.3ʹ W to 73°34.0ʹ S, 22°12.3ʹ W, 866–920 m, bottom trawl, 5 Feb. 1998, coll. C. De Broyer ( RBINS, INV. 13992); 1 spec., cruise PS48,ANT-XV/3, EASIZ II, stn 120, eastern Weddell Sea, 73°33.5ʹ S, 22°14.8ʹ W to 73°34.0ʹ S, 22°12.2ʹ W, 812–928 m, bottom trawl, 7 Feb. 1998, coll. C. De Broyer ( RBINS, INV. 13993).

RV Aurora Australis cruises:

SOUTHERN OCEAN: 4 specs including an ovigerous ♀, cruise CEAMARC, sample CEAMARC 3410, stn 86EEV518, Adélie Coast, 65°28ʹ51″ S, 139°24ʹ11″ E, 781–835 m, beam trawl, 16 Jan. 2008, coll. IPEV-AAD-MNHN (MNHN-IU-2014-4278); 1 dissected ovigerous ♀, cruise CEAMARC, sample CEAMARC 3410, stn 86EEV518, Adélie Coast, 65°28ʹ51″ S, 139°24ʹ11″ E, 781–835 m, beam trawl, 16 Jan. 2008, coll. IPEV-AAD-MNHN (MNHN-IU-2014-7343) [removed from MNHN-IU-2014-4278] [extraction M17; Genbank nr, COI: KU870883 , 18S: KU759666 ]; 1 spec., cruise CEAMARC, sample CEAMARC 2268, stn 32AEV400, Adélie Coast, 65°52ʹ44″ S, 144°10ʹ55″ E, 953–1194 m, beam trawl, 12 Jan. 2008, coll. IPEV-AAD-MNHN (MNHN-IU-2014-4285); 1 ovigerous ♀, cruise CEAMARC, sample CEAMARC 2271, stn 32AEV400, Adélie Coast, 65°52ʹ44″ S, 144°10ʹ55″ E, 953–1194 m, beam trawl, 12 Jan. 2008, coll. IPEV-AAD-MNHN (MNHN-IU-2014-4281) [extraction M18; Genbank nr, COI: KU870884 , 18S: KU759667 ]; 3 specs, cruise CEAMARC, sample CEAMARC 2271, stn 32AEV400, Adélie Coast, 65°52ʹ44″ S, 144°10ʹ55″ E, 953–1194 m, beam trawl, 12 Jan. 2008, coll. IPEV-AAD-MNHN, (MNHN-IU-2014-7344, formerly MNHN-IU-2014-4281).

Description

ROSTRUM. Medium-sized, reaching tip of article 1 of peduncle of antenna 1, anteriorly distinctly curved, ventrally distinctly concave, subacute in lateral view; narrow and with nearly straight converging borders in frontal view.

EYE. Very large, distinctly reniform.

PEREION–PLEOSOME TOOTH PATTERN. Pereionite 1 with trace of mid-dorsal carina and no posterior bump; pereionites 2 to pleonite 3 with low and fairly blunt mid-dorsal carina, which becomes more and more laterally compressed in the posterior body segments; profile of carina of pereionite 2 straight, of pereionites 3 to pleonite 3 with median notch (more distinct on pleonites than on pereionites); profile of carina of pleonite 3 straight with anterior very low protrusion followed by shallow notch, then nearly straight (slightly irregular), posteriorly bluntly angular; dorsolateral ornamentation absent.

COXAE 1–3. Not carinate and apically forming a blunt squared angle.

COXA 4. Anterodorsal border nearly straight (very slightly concave), anteroventral border straight, these two borders being joined by blunt but distinct angular discontinuity (anterior corner), which is weakly projecting forward; ventral corner forming a blunt squared angle (ventral projection well developed); lateral carina absent; posteroventral border distinctly concave.

COXA 5. Broad, with surface smooth, with posteroventral corner forming a blunt-tipped nearly squared angle, weakly expanded laterally, forming a blunt obtuse angle in dorsal view.

COXA 6. With posteroventral corner forming a blunt acute but nearly squared angle, with low projection arising from its surface (forming a very low indistinct lobe in dorsal view).

COXA 7. Posteriorly rounded.

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

UROSOME TOOTH PATTERN. Urosomite 1 with very low dorsal process, irregularly convex on both sides; urosomite 3 with dorsolateral borders nearly straight.

TELSON. Cleft on 0.2; tips of lobes triangular and subacute, notch broadly V-shaped and rounded at its deepest point.

GNATHOPODS 1–2. Carpus and propodus broad; propodus expanding distally, palm distinct.

PEREIOPODS 5–7. Merus, carpus and propodus of medium width; dactylus medium-sized; basis of pereiopods 5–6 of normal width, with posteroproximal process present, sword-like, parallel to axis of basis, with posterodistal corner rounded, very weakly pointing in posterior direction; basis of pereiopod 7 broad with posterior border weakly convex, with distinct notch on distal 0.8, forming a blunt-tipped obtuse (nearly square) angle, with posterodistal corner bluntly angular and not pointing backwards.

Colour pattern

Uniformly whitish, eyes yellowish ( Lörz et al. 2011), or uniformly pale orange, eyes golden ( Rauschert & Arntz 2015 as ‘ Epimeria inermis 3’, p. 61, pl. 54), or uniformly salmon pink with reddish eyes (picture made by G. Chapelle published herein).

Body length

Up to 40 mm.

Distribution

Eastern shelf of the Weddell Sea; Adélie Coast; 781–1194 m.

Remarks

The new records of E. angelikae off Adélie Coast considerably extend eastwards the distribution of the species. No morphological differences were detected between these specimens, the illustrations given by Lörz et al. (2011) and the specimens examined from the Weddell Sea. One of the main diagnostic characters proposed by Lörz et al. (2011) for distinguishing E. angelikae from other species of the georgiana complex is the obtusely notched posterior border of the basis of pereiopod 7. This character is valid for adults. However, the depth and the angularity of that notch is a character to be used with caution, as it is partly size-dependent: the notch is shallow in juveniles of all species of the georgiana complex and becomes gradually deeper and more angulate in some species only, as size increases. Epimeria angelikae is superficially similar to E. xesta sp. nov. The two species coexist on the eastern shelf of the Weddell Sea, but have apparently different depth optima. The ‘ Epimeria inermis 3’ of Rauschert & Arntz (2015) corresponds to the description of E. angelikae and not to that of E. inermis , as it has a short rostrum, reniform eyes, the posteroventral border of coxa 4 concave and a median spur on the basis of pereiopods 5 and 6. The station of this specimen was given in an early draft of their book made available to the authors: ANT-XXI/2 stn 233 [233-1]. Its coordinates are: 71°18.99ʹ S, 13°56.56ʹ W to 71°19.19ʹ S, 13°57.45ʹ W (eastern Weddell Sea), 844– 848 m.

Figures

Fig. 132. Epimeria (Hoplepimeria) angelikae subgen. nov. Lörz & Linse in Lörz et al., 2011, ♀, adult, Adélie Coast, CEAMARC 3410, MNHN-IU-2014-7343. A. Lateral habitus. B. Dorsal habitus.

Fig. 133. Epimeria (Hoplepimeria) angelikae subgen. nov. Lörz & Linse in Lörz et al., 2011, ♀, adult, Adélie Coast, CEAMARC 3410, MNHN-IU-2014-7343. A. Facial habitus. B. Head in facial view.

Fig. 134. Epimeria (Hoplepimeria) angelikae subgen. nov. Lörz & Linse in Lörz et al., 2011, ♀, adult, Adélie Coast, CEAMARC 3410, MNHN-IU-2014-7343. A. Coxae 1–7. B. Pleon.

Fig. 135. Epimeria (Hoplepimeria) angelikae subgen. nov. Lörz & Linse in Lörz et al., 2011, ♀, adult, Adélie Coast, CEAMARC 3410, MNHN-IU-2014-7343. A. Head in lateral view. B. Urosome in dorsal view. C. Telson.

Fig. 136. Epimeria (Hoplepimeria) angelikae subgen. nov. Lörz & Linse in Lörz et al., 2011. A–B, ♀, adult, Adélie Coast, CEAMARC 3410, MNHN-IU-2014-7343. C, eastern Weddell Sea, ANT-VII/4, no station. A. Gnathopod 1. B. Gnathopod 2. C. Habitus in colour. There is no evidence of symbiosis with sponges: there was simply a sponge in the aquarium used for photography. Colour photograph by Gauthier Chapelle (formerly RBINS).

Fig. 137. Epimeria (Hoplepimeria) angelikae subgen. nov. Lörz & Linse in Lörz et al., 2011, ♀, adult, Adélie Coast, CEAMARC 3410, MNHN-IU-2014-7343. A. Pereiopod 4. B. Pereiopod 5. C. Pereiopod 6. D. Pereiopod 7.