Epimeria (Laevepimeria) anodon, 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 : 108-109

Epimeria (Laevepimeria) anodon subgen. et sp. nov.

urn:lsid:zoobank.org:act:4328C52C-34BA-4DDF-A984-7BDE24BADE7F

Figs 229–234

‘ Clade C walkeri complex - WA4’ – Verheye et al. 2016a, supplement: 3 (online).

Etymology

Combination of the prefix an-, which means ‘lack of’ and of the Greek noun, όδούς, which means ‘teeth’. The name, which is an apposition, alludes to the absence of tooth in the species.

Type material

Holotype

RV Aurora Australis cruises:

SOUTHERN OCEAN: ♀, cruise CEAMARC, sample CEAMARC 2724, stn 71EV447, Adélie Coast, 66°24ʹ00″ S, 140°32ʹ21″ E, 683–791 m, beam trawl, 14 Jan. 2008, coll. IPEV-AAD-MNHN ( MNHN- IU-2014-4336 ) [extraction M13; Genbank nr, COI: KU870880 , 28S: KU759664 ].

Paratypes

RV Aurora Australis cruises:

SOUTHERN OCEAN: 1 spec., cruise CEAMARC, sample CEAMARC 1317, stn 51AEV215, Adélie Coast, 66°44ʹ52″ S, 145°26ʹ40″ E, 525–553 m, beam trawl, 30 Dec. 2007, coll. IPEV-AAD-MNHN (MNHN-IU-2014-4275); 1 adult spec., cruise CEAMARC, sample CEAMARC 1384, stn 50AEV220, Adélie Coast, 66°45ʹ09″ S 145°20ʹ04″ E, 567–604 m, beam trawl, 30 Dec. 2007, coll. IPEV-AAD- MNHN (MNHN-IU-2014-4331) [extraction M12; Genbank nr, COI: KU870879 , 28S: KU759663 ]; 1 ♀, cruise CEAMARC, sample CEAMARC 2724, stn 71EV447, Adélie Coast, 66°24ʹ00″ S, 140°32ʹ21″ E, 683–791 m, beam trawl, 14 Jan. 2008, coll. IPEV-AAD-MNHN (MNHN-IU-2014-7335) [removed from MNHN-IU-2014-4336].

Description

HEAD + ROSTRUM. Normally curved in lateral view.

ROSTRUM. In lateral view short and very broad, reaching mid of article 1 of peduncle of antenna 1, anteriorly distinctly curved, ventrally weakly convex, tip subacute; in frontal view very broad and with nearly straight converging borders, tip blunt.

EYES. Medium-sized, elliptic, laterally oriented (interocular distance about 3 × as wide as eye size when seen in frontal view).

PEREION–PLEOSOME TOOTH PATTERN. Pereionites 1–7 totally smooth; pleonites 1–2 with trace of mid-dorsal keel and with trace of posterior bump; pleonite 3 with trace of mid-dorsal carina and with posterior bump.

COXAE 1–3. Tip sharp.

COXA 4. Broad, anterodorsal border straight; anteroventral border nearly straight (inconspicuously convex), these two borders being joined by broad rounded convexity, which is distinctly projecting forward; anterodorsal border 1.35 × as long as anteroventral border; posteroventral border nearly straight (inconspicuously sinuate).

COXA 5. Very broad, posteroventral corner very broadly rounded in lateral view, very obtusely rounded in dorsal view (almost not projecting laterally).

COXA 6. Posterior border weakly convex; posteroventral corner very broadly rounded.

COXA 7. Posterior border nearly straight (inconspicuously concave); posteroventral corner broadly rounded.

EPIMERAL PLATES 1–3. Posteroventral angle very obtusely rounded in plate 1 (without any trace of tooth), produced into a small tooth in plates 2–3.

UROSOME TOOTH PATTERN. Urosomite 1 with distinct asymmetrical dorsal process, anteriorly nearly straight, apically blunt, posteriorly strongly convex; urosomite 3 with dorsolateral borders weakly convex, with tip broadly rounded.

TELSON. Cleft on 0.2; lobes laterally very convex, medially nearly straight, with tips subacute; notch with borders weakly convergent and end rounded.

GNATHOPODS 1–2. Carpus and propodus short and very broad; propodus not expanding distally, palm very reduced (dactylus 4 × as long as palm; gnathopods achelate or nearly so).

PEREIOPOD 4. Merus, carpus and propodus long and slender, dactylus short.

PEREIOPOD 5. Basis of normal width, with posteroproximal process absent, with posterodistal corner forming a very obtuse angle (not projecting posteriorly) of which the tip is very blunt; merus, carpus and propodus long and slender, dactylus short.

PEREIOPOD 6. Basis of normal width, with posteroproximal process absent, with posterodistal corner very broadly rounded (not angulate); merus, carpus and propodus long and slender, dactylus short.

PEREIOPOD 7. Basis broad; posterior border weakly convex and slightly diverging in proximal 0.8, at this level forming a blunt but strong angular discontinuity and abruptly and very strongly converging (border becoming inconspicuously concave, terminated into a small, blunt but distinctly protruding lobe; merus very broad and short, carpus of medium width and short, propodus slender and short, dactylus short.

Colour pattern

Uniformly pale yellowish; eyes blood red.

Body length

Up to 32 mm.

Distribution

Adélie Coast, 525– 791 m.

Remarks

Epimeria anodon sp. nov. and E. walkeri are very similar in morphology. Epimeria anodon sp. nov. has smaller eyes and the posterodistal corner of the basis of its pereiopods 5 and 6 is very broadly rounded, which is not the case for the other two species. In dorsal view, pleonites 1–3 are also less smooth than in E. walkeri .

Figures

Fig. 229. Epimeria (Laevepimeria) anodon subgen. et sp. nov., sex undetermined, Adélie Coast. A–B, CEAMARC 2724, MNHN-IU-2014-4336. C, CEAMARC V3 1106 (photograph: Frédéric Busson, MNHN); specimen not examined. A. Lateral habitus. B. Dorsal habitus. C. Colour in life.

Fig. 230. Epimeria (Laevepimeria) anodon subgen. et sp. nov., sex undetermined, Adélie Coast, CEAMARC 2724, MNHN-IU-2014-4336. A. Facial habitus. B. Head in facial view.

Fig. 231. Epimeria (Laevepimeria) anodon subgen. et sp. nov., sex undetermined, Adélie Coast, CEAMARC 2724, MNHN-IU-2014-4336. A. Anterior half. B. Posterior half.

Fig. 232. Epimeria (Laevepimeria) anodon subgen. et sp. nov., sex undetermined, Adélie Coast, CEAMARC 2724, MNHN-IU-2014-4336. A. Head in lateral view. B. Urosome in dorsal view. C. Telson.

Fig. 233. Epimeria (Laevepimeria) anodon subgen. et sp. nov., sex undetermined, Adélie Coast, CEAMARC 2724, MNHN-IU-2014-4336. A. Gnathopod 1. B. Gnathopod 2.

Fig. 234. Epimeria (Laevepimeria) anodon subgen. et sp. nov., sex undetermined, Adélie Coast, CEAMARC 2724, MNHN-IU-2014-4336. A. Pereiopod 4. B. Pereiopod 5. C. Pereiopod 6. D. Pereiopod 7.