Epimeria (Hoplepimeria) linseae, 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 : 90-92

Epimeria (Hoplepimeria) linseae subgen. et sp. nov.

urn:lsid:zoobank.org:act:261E7087-B67B-47ED-905B-FB8FF8C636D8

Figs 192–197

Epimeria georgiana – Coleman 2007: 37, fig. 16a–b.

Epimeria georgiana Clade B –? Lörz et al. 2011: 3, fig. 1 (circle), fig. 13 row 2, 14C, 14D, table 3.

‘Clade E georgiana-rimicarinata-rubriequies [sic] complex - GE2ʹ – Verheye et al. 2016a, supplement: 4 (online).

non Epimeria georgiana Schellenberg, 1931: 160 .

Etymology

The species is dedicated to Katrin Linse (British Antarctic Survey, Cambridge), who played an important role in the study of the Epimeria georgiana complex. The name is a genitive.

Type material

Holotype

RV Polarstern Cruises:

SOUTHERN OCEAN: ♀, cruise PS77, ANT-XXVII/3, South Orkney Islands, stn 217-6, 61°09.62ʹ S, 44°02.37ʹ W to 61°10.52ʹ S, 44°04.91ʹ W, 350–354 m, bottom trawl, 19 Feb. 2011, coll. C. Havermans and H. Robert ( RBINS, INV. 132958 ) [extraction I10; Genbank nr, COI: KU870838 , 28S: KU759612 ]. Paratypes

Expedition SIGNY 1991/92 (name of ship unavailable):

SOUTHERN OCEAN: 1 large ♀, Transect 1, AGT 8, South Orkney Plateau: Signy Island, 60.679° S, 45.557° W, 150–160 m, 14 Jan. 1992, coll. Stefan Hain ( RBINS, INV. 132688); 1 fairly small spec., Transect 2, AGT 23, South Orkney Plateau: Signy Island, 60.691° S, 45.443° W, 150–160 m, 14 Feb. 1992, coll. Stefan Hain ( RBINS, INV. 132689); 1 large ♀, Transect 2, AGT 14, South Orkney Plateau: Signy Island, 60.705° S, 45.557° W, 150 m, 5 Feb. 1992, coll. Stefan Hain ( RBINS, INV. 132690); 1 adult ♀, Transect 1, AGT 4, South Orkney Plateau: Signy Island, 60.685° S, 45.573° W, 100–140 m, 9 Jan. 1992, coll. Stefan Hain ( RBINS, INV. 132691).

Description

ROSTRUM. Large, nearly reaching tip of article 2 of peduncle of antenna 1, anteriorly slightly curved, ventrally inconspicuously concave, blunt-tipped in lateral view; narrow and with borders weakly convex in frontal view.

EYE. Fairly large, nearly round.

PEREION–PLEOSOME TOOTH PATTERN. Pereionite 1–3 smooth; pereionites 4 with posterior bump and trace of carina; pereionites 5 to pleonite 3 with low, non-toothed, very broad carina, that of pleonite 2 with trace of concavity on anterior 0.4; pleonite 3 with weak dorsal protuberance followed by weak concavity followed by trace of second concavity; posterodorsal angle of pleonite 3 bluntly angular; dorsolateral ornamentation absent.

COXAE 1–3. Scarcely carinate and apically tapering, sharp to subacute.

COXA 4. Anterodorsal border nearly straight (very weakly sigmoid), anteroventral border weakly concave, these two borders being joined by blunt but very distinct angle (anterior corner), which is distinctly projecting forward; ventral corner forming a sharp or subacute squared angle (ventral projection short); lateral carina present but 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 broadly rounded obtuse (nearly square) angle which is very distinct in dorsal view.

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

COXA 7. Posteriorly rounded.

EPIMERAL PLATES 1–3. Posteroventral angle: produced into a small tooth in plates 1–2 and into a mediumsized tooth in plate 3.

UROSOME TOOTH PATTERN. Urosomite 1 with very low dorsal process, anteriorly slightly concave, apically rounded and posteriorly oblique and straight; urosomite 3 with dorsolateral borders nearly straight (inconspicuously concave), with tip sharply angular.

TELSON. Cleft on 0.25; lobes broad, forming subacute triangle; notch V-shaped, neither very narrow nor very broad.

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

PEREIOPODS 5–7. Merus, carpus and propodus of medium width; dactylus rather long; basis of pereiopods 5–6 of normal width, with posteroproximal process present, tooth-like, parallel to axis of basis, with posterodistal corner bluntly angular, very weakly 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 squared or acute angle, with posterodistal corner rounded and not projecting backwards.

Colour pattern

Body and appendages with a diffuse orange dotted/mottled pattern, more intense in some parts; eye reddish.

Body length

Up to 35 mm.

Distribution

Plateau of the South Orkney Islands. Our specimens were collected between 100 and 354 m. If we are correct in identifying the ‘ Epimeria georgiana clade B’ of Lörz et al. (2011) as E. linseae sp. nov., the species descends down to 964–1014 m.

Remarks

E. linseae sp. nov. is morphologically similar to E. quasimodo sp. nov. The best differential character is the shape of the rostrum, which is narrower (both in lateral and dorsal view) and laterally more curved in the first than in the second species. The dorsal profile of pleonite 3 and urosomite 3 is also slightly different. Material from Coleman (2007) is here attributed to E. linseae sp. nov. based on morphology (especially for the shape of the rostrum) and collection location: 60°43.12ʹ S, 45°30.86ʹ W (South Orkney Islands), 141–190 m, Agassiz trawl, 3.1.1985, leg. Wägele (Coleman pers. com.).

Figures

Fig. 192. Epimeria (Hoplepimeria) linseae subgen. et sp. nov. A–B, ♀, holotype, South Orkney Islands, ANT-XXVII/3, stn 217-6, RBINS, INV. 132958. C–E, South Orkney Islands, ANT-XXVII/3, stn 217-5, specimen not available.A. Lateral habitus. B. Dorsal habitus. C–E. Colour in life (photograph: H. Robert and C. Havermans, RBINS).

Fig. 193. Epimeria (Hoplepimeria) linseae subgen. et sp. nov., ♀, holotype, South Orkney Islands, ANT-XXVII/3, stn 217-6, RBINS, INV. 132958. A. Facial habitus. B. Head in facial view.

Fig. 194. Epimeria (Hoplepimeria) linseae subgen. et sp. nov., ♀, holotype, South Orkney Islands, ANT-XXVII/3, stn 217-6, RBINS, INV. 132958. A. Coxae 1–7. B. Pleonite 3 and urosome.

Fig. 195. Epimeria (Hoplepimeria) linseae subgen. et sp. nov., ♀, holotype, South Orkney Islands, ANT-XXVII/3, stn 217-6, RBINS, INV. 132958. A. Head in lateral view. B. Urosome in dorsal view. C. Telson.

Fig. 196. Epimeria (Hoplepimeria) linseae subgen. et sp. nov., ♀, holotype, South Orkney Islands, ANT-XXVII/3, stn 217-6, RBINS, INV. 132958. A. Gnathopod 1. B. Gnathopod 2.

Fig. 197. Epimeria (Hoplepimeria) linseae subgen. et sp. nov., ♀, holotype, South Orkney Islands, ANT-XXVII/3, stn 217-6, RBINS, INV. 132958. A. Pereiopod 4. B. Pereiopod 5. C. Pereiopod 6. D. Pereiopod 7.