Epimeria (Subepimeria) puncticulata K.H. Barnard, 1930

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 : 148-149

Epimeria (Subepimeria) puncticulata K.H. Barnard, 1930

Epimeria puncticulata K.H. Barnard, 1930: 377 , fig. 42.

Epimeria puncticulata – Gurjanova 1955: 197. — McCain 1971: 161. — De Broyer 1983: 305 (discussion). — De Broyer & Klages 1991: 164 (key). — Coleman 1994: 569, figs 13–16 [holotype]; 1998b: 223–224 (in part). — Wakabara & Serejo 1999: 643 (key). — Coleman 2007: 48, in part, fig. 25 [holotype], not plate 2 fig. d [= Epimeria (Subepimeria) sp.], map 12 (circle) [in part].

Description

Basis of description. Description based on the accounts on the holotype published by K.H. Barnard (1930) and Coleman (1994); when illustrations are conflicting, description based on Coleman (1994).

ROSTRUM. In lateral view very narrow.

EYES. Medium-sized, narrowly elliptic.

PEREION–PLEOSOME TOOTH PATTERN. Pereionites 1–7 totally smooth; pleonite 1 with feeble indication of a keel; pleonite 2 keeled with well developed acute posterodorsal tooth; pleonite 3 keeled with posterodorsal tip forming a distinct blunt process distinctly projecting backwards.

COXAE 1–2 (cf. Coleman 1994). Tip subacute to rather blunt; coxa 3: tip rounded.

COXA 4 (cf. Coleman 1994). Fairly narrow; anterodorsal border nearly straight (inconspicuously convex); anteroventral border weakly convex; anterior corner very broadly rounded but forming a distinct angular discontinuity; the coxa is slightly projecting forward; ventral corner forming a squared angle of which the tip is subacute; posteroventral border distinctly concave; posterodorsal border 0.8 × as long as posteroventral border.

COXA 5. Very broad, posteroventral corner forming a blunt but distinct squared angle.

COXA 6. Posterior border regularly rounded.

COXA 7. Posterior border straight; posteroventral corner forming a distinct obtuse angle.

EPIMERAL PLATES 1–3. Posteroventral angle with trace of tooth in plate 1, produced into a small tooth in plate 2, produced into a medium-sized tooth in plates 3.

UROSOME TOOTH PATTERN. Urosomite 1 with triangular dorsal process.

TELSON. Cleft on 0.2; lobes with tips rounded; notch V-shaped.

GNATHOPODS 1–2. With carpus and propodus of normal slenderness; propodus not narrowing distally, and palm distinct but weak.

PEREIOPOD 5. Basis of normal width, with posteroproximal process reduced to low proximal dilatation in continuity with the more distal part of the posterior border, with posterodistal corner forming a fairly narrow, acutely triangular tooth projecting backwards; merus, carpus and propodus stout.

PEREIOPOD 6. Basis of normal width, with posteroproximal process reduced to very low proximal dilatation nearly in continuity with the more distal part of the posterior border), with posterior border parallel to anterior border, with posterodistal corner forming a triangular process (acute, nearly squared angle) very weakly projecting backwards; merus, carpus and propodus stout.

PEREIOPOD 7. Basis broad; posterior border weakly convex, with inconspicuous trace of concavity in distal 0.9, terminated into a very blunt, obtuse angle.

Body length

Up to 16 mm.

Distribution

Ross Sea, McMurdo Sound, 175 m (K.H. Barnard 1930).

Remarks

Watling & Holman (1981) and Coleman (2007) considered Epimeria puncticulata as a single widespread and variable species. Yet, genetic data (COI, 28S) ( Verheye et al. 2016a) based on a limited material indicate the existence of four different species refered herein as E. adeliae sp. nov., E. iota sp. nov., E. teres sp. nov. and E. urvillei sp. nov. ( Fig. 342 ). Examination of published illustrations suggest the existence of four additional species: E. geodesiae , E. puncticulata s. str., E. ( Subepimeria ) sp. 1 and E. ( Subepimeria ) sp. 2. Coxa 4 of the holotype of E. puncticulata is different in the drawings of K.H. Barnard (1930) and those of Coleman (1994). This might result from different orientations of the specimens.

Figures

Fig. 342. Phylogenetic tree obtained by Bayesian analysis of the concatenated COI and 28S sequences, updated from Verheye et al. (2016). Bayesian posterior probabilities and bootstrap values (from the Maximum Likelihood analysis) are indicated above the nodes of interest. Bootstrap values inferior to 50 are not indicated. Besides the species names are indicated the MOTUs codes used in Verheye et al. (2016). The Genbank accession number of the outgroup species: Gnathiphimedia sexdentata (Schellenberg, 1926) are KU870835 (COI) and KU759609 (28S).