Epimeria (Subepimeria) geodesiae Bellan-Santini, 1972

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 : 143-145

Epimeria (Subepimeria) geodesiae Bellan-Santini, 1972

Subepimeria geodesiae Bellan-Santini, 1972: 225 , pls 33–34.

Epimeria puncticulata – Watling & Holman 1981: 213–215 (discussion, in part), not fig. 21 (= E. (Subepimeria) iota sp. nov.); Coleman 1998b: 223–224 (in part).

Subepimeria geodesiae – De Broyer 1983: 305 (discussion).

Description

Description based on the illustrations of Bellan-Santini (1972).

ROSTRUM. Reaching tip of article 1 of peduncle of antenna 1, broad in lateral view.

EYES. Large, rounded.

PEREION–PLEOSOME TOOTH PATTERN. Pereionites 1–7 totally smooth; pleonite 1 toothless; pleonite 2 with small, posterodorsal tooth; pleonite 3 with posterodorsal tip forming a small, distinct rounded (very broadly triangular) lobe projecting backwards.

COXAE 1–3. Tip subacute in coxae 1–2, blunt in coxa 3.

COXA 4. Very narrow; anterodorsal border weakly convex, directly followed by very broadly rounded ventral lobe (anteroventral border absent); posteroventral border nearly straight (weakly concave); ratio length of posterodorsal border / length of posteroventral border: 0.5.

COXA 5. Very broad, posteroventral corner with broadly rounded angular discontinuity.

COXA 6. Posterior border regularly rounded.

COXA 7. Posterior border nearly straight (very weakly convex); posteroventral corner broadly rounded.

EPIMERAL PLATES 1–3. Posteroventral angle angulate in plate 1, produced into a small tooth in plate 2; produced into a medium-sized tooth in plate 3.

UROSOME TOOTH PATTERN. Urosomite 1 with narrow triangular dorsal process; urosomite 3 with dorsolateral borders straight, with tip produced into a long tooth pointing obliquely.

TELSON. Cleft on 0.25.

GNATHOPODS 1–2. Carpus and propodus of normal slenderness; propodus not narrowing distally, and palm distinct.

PEREIOPOD 5. Basis of normal width, with posteroproximal process indistinct (reduced to very low proximal dilatation in continuity with the more distal part of the posterior border), with posterodistal corner forming a blunt-tipped broadly triangular process (acute angle) projecting backwards; merus, carpus and propodus stout.

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

PEREIOPOD 7. Basis broad; posterior border weakly convex, with shallow concavity in distal 0.8, terminated into a sharp triangular tooth (forming a squared angle).

Body length

15 mm.

Distribution

Adélie Coast: Cape Géodésie, 115–135 m, on coarse sand with abundant epifauna: hydroids, bryozoans and sponges ( Bellan-Santini 1972).

Remarks

Watling & Holman (1981) synonymised Subepimeria geodesiae with Epimeria puncticulata , which they considered as a widely distributed variable species. Molecular data (COI, 28S) revealed different species within E. puncticulata s. lat. ( Verheye et al. 2016a; this paper Fig. 342 ), leading to the resurrection of Subepimeria , as a subgenus. The shape of coxa 4 of E. geodesiae as illustrated by Bellan-Santini (1972) is unique and does not fit with the descriptions of the holotype of E. puncticulata (K.H. Barnard 1930; Coleman 1994) or any other Subepimeria species. Epimeria geodesiae is considered here to be a valid species.

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).