Epimeria (Hoplepimeria) georgiana, 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 : 81-82

Epimeria (Hoplepimeria) georgiana subgen. nov. Schellenberg, 1931

Figs 152–158

Epimeria georgiana Schellenberg, 1931: 160 .

Epimeria excisipes K.H. Barnard, 1932: 174 , in part but well the types, presumably figs 104e, 107, not fig. 106 (presumably another Epimeria of the complex georgiana ).

Epimeria georgiana – Gurjanova 1955: 197. — J.L. Barnard 1961: 103 (key). — McCain 1971: 161. — Watling & Holman 1981: 211, in part, not fig. 19 (= E. quasimodo sp. nov.). — De Broyer & Klages 1991: 165 (key, in part). — Wakabara & Serejo 1999: 642 (key, in part). — Lörz et al. 2011: 1, figs 1 (star), 13 row 5, table 3.

Epimeria excisipes – Gurjanova 1955: 198 (in part). — J.L. Barnard 1961: 103 (key, in part). — McCain 1971: 161 (in part).

Type material

Lectotype

Swedish South Polar Expedition 1901–1903:

SOUTHERN OCEAN: ♀, from the syntype series, stn 34, South Georgia, in front of mouth of Cumberland Bay, 54°11ʹ S, 36°18ʹ W, grey clay, some stones, 252–310 m, T= +1.45°C, Skottsberg pinx. ( SMNH - type 673).

Description

ROSTRUM. Medium-sized, just overreaching tip of article 1 of peduncle of antenna 1, anteriorly distinctly curved, ventrally straight, subacute in lateral view; broad and with proximally nearly straight converging borders in frontal view.

EYE. Fairly large, broadly elliptic.

PEREION–PLEOSOME TOOTH PATTERN. Pereionite 1 smooth; pereionites 2–3 with weak posterior bump; pereionites 4 to pleonite 3 with low, non-toothed, very broad carina (not reduced on pereionites 2–3), those of pleonites 1–3 with trace of concavity in anterior 0.4; posterodorsal angle of pleonite 3 very bluntly angular; dorsolateral ornamentation absent.

COXAE 1–3. Scarcely carinate and apically tapering and blunt. COXA 4. Anterodorsal border weakly sigmoid, anteroventral border distinctly concave, these two borders being joined by very distinct and not so blunt angle (anterior corner), which is strongly projecting forward; ventral corner forming a sharp acute angle (ventral projection short); lateral carina present, not sharp; broad hollow surface between carina and posteroventral border of coxa; posteroventral border distinctly concave.

COXA 5. Broad, with surface smooth, with posteroventral corner forming a rounded lobe, weakly expanded laterally, forming a blunt squared angle which is very distinct in dorsal view.

COXA 6. With posteroventral corner rounded, with lateral projection arising from its surface (broadly triangular in dorsal view).

COXA 7. Posteriorly rounded.

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

UROSOME TOOTH PATTERN. Urosomite 1 with very low dorsal process, regularly convex on both sides; urosomite 3 with dorsolateral borders nearly straight (inconspicuously convex), with tip bluntly angular.

TELSON. Cleft on 0.4; lobes with rate of divergence abruptly increasing on their distal half, triangular and subacute in their distal half, median notch narrowly V-shaped.

GNATHOPODS 1–2. Carpus and propodus very broad; propodus expanding distally, palm distinct.

PEREIOPODS 5–7. Merus, carpus and propodus of medium width; dactylus medium-sized; basis of pereiopods 5–6 very broad, with posteroproximal process present, tooth-like, parallel to axis of basis, with posterodistal corner bluntly angular, distinctly produced and pointing in posterior direction; basis of pereiopod 7 broad with posterior border weakly convex, with distinct notch on distal 0.8, forming a blunt-tipped acute angle, with posterodistal corner bluntly angular and not projecting backwards.

Body length

Up to 40 mm.

Distribution

South Georgia, 75–310 m ( Schellenberg 1931).

Remarks

Epimeria georgiana s. str. is considered endemic to South Georgia and all extralimital records are presumably based on related species. The mention ‘Skottsberg pinx.’ (i.e., Skottsberg pinxit) on one of the labels of the lectotype suggests that Carl Johan Skottsberg made a painting of it during the Swedish Antarctic Expedition. Nothing is known about the fate of that painting. Besides the adult female examined and designated herein as the lectotype, Schellenberg (1931) recorded a mid-sized (20 mm) specimen and three juveniles (7–8 mm) of Epimeria georgiana , which become paralectotypes. These specimens were not examined.

Figures

Fig. 152. Epimeria (Hoplepimeria) georgiana subgen. nov. (Schellenberg, 1931), ♀, lectotype, South Georgia, Swedish South Polar Expedition 1901–1903, stn 34, SMNH - type 673. A. Lateral habitus. B. Dorsal habitus.

Fig. 153. Epimeria (Hoplepimeria) georgiana subgen. nov. (Schellenberg, 1931), ♀, lectotype, South Georgia, Swedish South Polar Expedition 1901–1903, stn 34, SMNH - type 673. A. Facial habitus. B. Head in dorsal view.

Fig. 154. Epimeria (Hoplepimeria) georgiana subgen. nov. (Schellenberg, 1931), ♀, lectotype, South Georgia, Swedish South Polar Expedition 1901–1903, stn 34, SMNH - type 673. A. Coxae 1–4. B. Dorsal profile of pleonite 3 and urosomites 1–2.

Fig. 155. Epimeria (Hoplepimeria) georgiana subgen. nov. (Schellenberg, 1931), ♀, lectotype, South Georgia, Swedish South Polar Expedition 1901–1903, stn 34, SMNH - type 673. A. Head in lateral view. B. Urosome in dorsal view. C. Telson.

Fig. 156. Epimeria (Hoplepimeria) georgiana subgen. nov. (Schellenberg, 1931), ♀, lectotype, South Georgia, Swedish South Polar Expedition 1901–1903, stn 34, SMNH - type 673. A. Maxilliped. B. Plates of maxiliped (detail). C. Maxilla 1. D. Maxilla 2.

Fig. 157. Epimeria (Hoplepimeria) georgiana subgen. nov. (Schellenberg, 1931), ♀, lectotype, South Georgia, Swedish South Polar Expedition 1901–1903, stn 34, SMNH - type 673. A. Gnathopod 1. B. Gnathopod 2.

Fig. 158. Epimeria (Hoplepimeria) georgiana subgen. nov. (Schellenberg, 1931), ♀, lectotype, South Georgia, Swedish South Polar Expedition 1901–1903, stn 34, SMNH - type 673. A. Basis of left pereiopods 1–7 (a white arrow was added on the photograph to draw the attention on the shape of the posterodistal corner of pereiopod 7). B. Basis of right pereiopods 1–7.