Epimeria (Pseudepimeria) amoenitas, 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 : 122-124

Epimeria (Pseudepimeria) amoenitas sp. nov.

urn:lsid:zoobank.org:act:191AE45C-F84D-412A-B0E1-CFA3251C5824

Figs 251–256

‘Clade H grandirostris-pulchra-oxicarinata complex - PUL1’ – Verheye et al. 2016a, supplement: 5 (online).

Etymology

From the Latin, a moenitas, -tatis: pleasantness, delightfulness, loveliness. This name, which is a noun in apposition, has been coined because the species is as elegant as its close relative Epimeria pulchra , of which the specific epithet means beautiful.

Type material

Holotype

RV Aurora Australis cruises:

SOUTHERN OCEAN: ♀ with hatchlings, cruise CEAMARC, sample CEAMARC 3978, stn 36EV297, Adélie Coast, 66°20ʹ19.806″ S, 143°41ʹ07.782″ E, 552–573 m, beam trawl, 4 Jan. 2008, coll. IPEV- AAD-MNHN ( MNHN-IU-2014-4327 ).

Paratype

RV Aurora Australis cruises:

SOUTHERN OCEAN: 1 spec., cruise CEAMARC, sample ‘CEAMARC V3 stn 158’, stn 28EV53, Adélie Coast, 65°59ʹ46.95″ S, 143°02ʹ57.0948″ E, 461–483 m, beam trawl, 23 Dec. 2007, coll. IPEV- AAD-MNHN (MNHN-IU-2014-4284) [extraction M14; Genbank nr, COI: KU870881 ].

Description

ROSTRUM. Long, overreaching tip of peduncle of antenna 1; in lateral view, anteriorly weakly curved in its middle and forming a blunt very obtuse angle with head, ventrally straight, tip not abruptly curving downwards; in frontal view, fairly narrow, with weakly convex borders, with subacute tip.

EYE. Medium-sized, conical.

PEREION–PLEOSOME TOOTH PATTERN. Pereionite 1 with medium-sized fairly broad and blunt-tipped middorsal tooth pointing upwards, of which the anterior border is straight and the posterior border is strongly convex, with pair of well-developed, blunt, dorsolateral teeth and pair of small ventrolateral teeth; pereionite 2 much narrower than pereionites 1 and 3, with small narrow blunt-tipped tooth pointing upwards (a bit shorter than mid-dorsal tooth of pereionite 1 and much shorter than mid-dorsal tooth of pereionite 3), with pair of small very blunt dorsolateral teeth, and pair of small ventrolateral teeth; pereionite 3 with large, broad and blunt mid-dorsal tooth pointing upwards, of which the anterior and the posterior borders are both strongly convex, with pair of medium-sized, low and blunt dorsolateral teeth, and pair of small ventrolateral teeth; pereionites 4–7 with large and broad mid-dorsal tooth pointing upwards, of which the anterior border is strongly convex and the posterior border weakly convex to nearly straight, and of which the tip is bluntly angulate to subacute, and with pair of medium-sized, low and blunt dorsolateral teeth, and pair of small ventrolateral teeth; pleonites 1–2 with large and broad mid-dorsal tooth pointing upwards, of which the anterior border is strongly convex (regularly convex for pleonite 1, with weak median angular discontinuity in pleonite 2) and the posterior border straight, of which the tip is subacute, with pair of large subacute dorsolateral teeth (anteriorly preceded by small but sharp denticle); pleonite 3 with medium-sized mid-dorsal tooth pointing upwards, of medium width, of which the anterior border is proximally convex and distally weakly concave, the tip narrow and acute and the posterior border nearly straight, with 5 pairs of dorsolateral teeth (the most posterior one very large and blunt).

COXAE 1–3. Strongly carinate and distally sharp.

COXA 4. Anterodorsal border straight; anteroventral border with proximal very distinct notch forming an obtuse angle, with distal part straight; anterior angle rounded and projecting forward; ventral tooth long, narrow and acute, directed backwards; lateral carina with rounded lobe strongly projecting laterally, posteriorly followed by fairly deep rounded concavity; in lateral view, inner corner of carina forming a distinct squared angle; in lateral view posteroventral border of coxa deeply concave, the deepest point of this concavity forming a blunt squared angle (more anteriorly and more distally the posterior border is nearly straight).

COXA 5. In dorsal view, with very long, triangular, carinate, lateral tooth, of which the anterior border points obliquely backwards and the posterior border is nearly perpendicular to body axis (very weakly pointing backwards); tip of carina sharp.

COXA 6. With triangular carinate lateral tooth of which the anterior border points obliquely backwards and the posterior border is nearly perpendicular to body axis (very weakly pointing onwards) (character to be examined in dorsal view); tip of carina sharp.

COXA 7. With ventral border distinctly curved, with posterior border very weakly concave, these two borders being joined by a broad curve.

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

UROSOME TOOTH PATTERN. Urosomite 1 with sharp narrow tooth pointing upwards, not anteriorly preceded by pair of denticles; urosomite 2 with pair of mid-sized posterior dorsolateral teeth pointing upwards; urosomite 3 with pair of mid-sized posterior dorsolateral teeth pointing upwards.

TELSON. Cleft on 0.4; tips of lobes subacute, notch forming a narrow slit.

PEDUNCLE OF ANTENNA 1. Article 1 with anterior border concave, with strong anterior and posterior tooth; article 2 with strong lateral triangular tooth; article 3 with strong ventral tooth.

GNATHOPODS 1–2. Very small, achelate; carpus and propodus of normal slenderness in gnathopod 1 (propodus tapering), extremely narrow in gnathopod 2; dactylus of gnathopod 2 moderately broad and posteriorly straight.

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, with posterodistal tooth strong, narrow and sharp; merus, carpus and propodus extremely broad and short; dactylus fairly large, strongly curved on both sides, clasping.

PEREIOPOD 7. Basis broad; posterior border parallel to axis of basis in proximal 0.75; at this level it forms a distinct squared angle, which is followed by a deep concavity; this concavity forms a rounded obtuse (nearly squared) angle; 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.

Body length

Up to 35 mm.

Distribution

Adélie Coast, 461– 573 m.

Remarks

Epimeria amoenitas sp. nov. (Adélie Coast) is very similar to E. debroyeri sp. nov. (eastern shelf of the Weddell Sea). In E. amoenitas sp. nov., pleonite 3 has a fairly broad and acute-tipped mid-dorsal tooth, whilst in E. debroyeri sp. nov., the same tooth is very broad and bluntly triangular. In E. amoenitas sp. nov., the posterior border of third epimeral plate is weakly curved, whilst in E. debroyeri sp. nov., it forms a strongly protruding curved projection. Finally, in E. amoenitas sp. nov., the tip of the lateral carina of coxa 5 is sharp in dorsal view, whilst in E. debroyeri sp. nov., it is blunt.

Figures

Fig. 251. Epimeria (Pseudepimeria) amoenitas sp. nov., ♀, holotype, Adélie Coast, CEAMARC 3978, MNHN-IU-2014-4327. A. Lateral habitus. B. Dorsal habitus.

Fig. 252. Epimeria (Pseudepimeria) amoenitas sp. nov., ♀, holotype, Adélie Coast, CEAMARC 3978, MNHN-IU-2014-4327. A. Facial habitus. B. Head in facial view.

Fig. 253. Epimeria (Pseudepimeria) amoenitas sp. nov., ♀, holotype, Adélie Coast, CEAMARC 3978, MNHN-IU-2014-4327. A. Coxae. B. Urosome and posterior part of pleosome.

Fig. 254. Epimeria (Pseudepimeria) amoenitas sp. nov., ♀, holotype, Adélie Coast, CEAMARC 3978, MNHN-IU-2014-4327. A. Head in lateral view. B. Urosome in dorsal view. C. Telson.

Fig. 255. Epimeria (Pseudepimeria) amoenitas sp. nov., ♀, paratype, Adélie Coast, CEAMARC V3, stn 158, MNHN-IU-2014-4284. A. Peduncle of antenna 1 in lateral view. B. Peduncle of antenna 2 in medial view. C. Gnathopod 1. D. Gnathopod 2.

Fig. 256. Epimeria (Pseudepimeria) amoenitas sp. nov., ♀, paratype, Adélie Coast, CEAMARC V3, stn 158, MNHN-IU-2014-4284. A. Pereiopod 4. B. Pereiopod 5. C. Pereiopod 6. D. Pereiopod 7.