Epimeria (Pseudepimeria) pulchra Coleman, 1990

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 : 138-139

Epimeria (Pseudepimeria) pulchra Coleman, 1990

Fig. 293

Epimeria pulchra Coleman, 1990a: 166–176 , pls 10–16.

Epimeria pulchra – De Broyer & Klages 1991: 166 (key). — Wakabara & Serejo 1999: 641 (key). — Coleman 2007: 47, in part, fig. 24a–b, not colour plate 2f (= E. debroyeri sp. nov.).

Material examined

SOUTHERN OCEAN: 2 adult specs, SIGNY 1991/92, AGT 5, transect 1, South Orkney Plateau: Signy Island, 60.683° S, 45.581° W, 50 m, 10 Jan. 1992, coll. Stefan Hain ( RBINS, INV. 132687).

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 weakly curved, tip sometimes 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 broad and blunt-tipped mid-dorsal 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; pereionites 3–7 with very large, slender and blunt-tipped mid-dorsal tooth pointing upwards, of which the anterior and the posterior borders are similarly convex, with pair of small, low and blunt dorsolateral teeth, and pair of small ventrolateral teeth; pleonite 1 with very large and slender mid-dorsal tooth pointing upwards, of which the anterior and posterior borders are convex (anterior border with distinct subdistal angular discontinuity), and of which the tip is blunt to angulate, and with pair of large subacute dorsolateral teeth (associated with several pairs of smaller denticles); pleonite 2 with very large and slender mid-dorsal tooth pointing upwards, of which the anterior and posterior borders are convex, and of which the tip is angulate, and with pair of large subacute dorsolateral teeth (associated with several pairs of smaller denticles); pleonite 3 with very narrow and very large mid-dorsal tooth pointing upwards, of which the anterior border is not convex, and the tip sharp and narrow, with 5 pairs of dorsolateral teeth.

COXAE 1–3. Strongly carinate and distally subacute.

COXA 4. Anterodorsal border straight; anteroventral border with median very deep angulate concavity (anterior border of concavity concave; posterior border of concavity straight); anterior angle produced into a large broad tooth projecting forward; ventral tooth fairly long, narrow and subacute, pointing weakly obliquely backwards; lateral carina with bluntly angulate lobe strongly projecting laterally, posteriorly followed by fairly deep rounded concavity, and more backwards by a second, lower but distinct lobe projecting laterally; 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 very rounded, obtuse (nearly squared) angle.

COXA 5. In dorsal view, with extremely long, triangular, carinate, lateral tooth, of which the anterior border points obliquely strongly backwards and the posterior border is almost perpendicular to body axis; 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); tip of carina subacute; posteriorly with a second, much smaller obtuse triangular tooth directed backwards.

COXA 7. With ventral border strongly curved, with posterior border straight, these two borders being joined by a long broad curve.

EPIMERAL PLATES 1–3. Plate 1 with posteroventral angle angulate and with posterior border distinctly angulate, with distinct lateral carina and 2 lateral teeth; plate 2 with posteroventral angle produced into a medium-sized sharp tooth, 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 produced into a large triangular tooth.

UROSOME TOOTH PATTERN. Urosomite 1 with sharp narrow tooth pointing upwards, with pair of denticle just in front of the main tooth; 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 0.3; tips of lobes acute, notch forming a narrow V.

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 broad in gnathopod 1 (propodus tapering), of medium width in gnathopod 2; dactylus of gnathopod 2 extremely broad and posteriorly straight.

PEREIOPOD 3–4. Merus, carpus and propodus extremely broad and short; dactylus fairly large, strongly curved on both sides, clasping.

PEREIOPODS 5–6. Basis of pereiopods 5–6 of normal width, with posteroproximal process produced into a sharp tooth, 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 nearly parallel to basis axis of proximal 0.75; at this level it forms a medium-sized sharp to very sharp tooth, which is followed by a deep rounded concavity; the posterodistal corner is produced into a medium to 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

Plateau of the South Orkney Islands, 50–190 m ( Coleman 1990; present material).

Remarks

Epimeria pulchra is superficially similar to E. amoenitas sp. nov. and E. debroyeri sp. nov., but it differs from these two species by a number of characters such as: longer mid-dorsal teeth on pereionites 3–7 and pleonites 1–2, much longer mid-dorsal tooth on pleonite 3, anterior corner of coxa 4 much more produced, posterior border of third epimeral plate produced into a tooth instead of being simply convex, gnathopods much broader. It is likely that E. pulchra s. str. is endemic to the South Orkney Islands, just as E. linseae sp. nov.

Figures

Fig. 293. Epimeria (Pseudepimeria) pulchra Coleman, 1990, adult ♀, Signy Island, SIGNY 1991/92, AGT 5, transect 1, RBINS, INV. 132687. A. Lateral view. B. Dorsal view.