Epimeria (Drakepimeria) similis d'Acoz & Verheye 2017, subgen. nov.

Epimeria (Drakepimeria) similis subgen. nov. Chevreux, 1912

Figs 106–124

Epimeria similis Chevreux, 1912: 215.

Epimeria similis – Chevreux 1913: 149, fig. 41. — Andres 1985: 124–125 (in part) — De Broyer & Klages 1991: 165 (key, in part). — Coleman 2007: 54, in part, fig. 30a–b, map 11 (circle, at least in part), not plate 1 fig. e (= Epimeria acanthochelon sp. nov.).

Epimeria macrodonta f. similis – Gurjanova 1955: 195.

‘ Clade A similis / macrodonta complex - SI4’ – Verheye et al. 2016a, supplement: 2 (online).

Type material

Lectotype (designated here)

RV Pourquoi Pas? Cruises:

SOUTHERN OCEAN: undissected ovigerous ♀, second French Antarctic expedition 1908–1910, Draguage XVII, South Shetlands, King George Island, Admiralty Bay, 420 m (n° 713) (MNHN Am. 5984 and MNHN-IU-2013-17865).

Paralectotype (designated here)

RV Pourquoi Pas? Cruises:

SOUTHERN OCEAN: 1 ♀ dissected by E. Chevreux, second French Antarctic expedition 1908–1910, Draguage XVII, South Shetlands King George Island, Admiralty Bay, 420 m (MNHN Am. 3095 and MNHN-IU-2013-17864).

Other material examined

RV Polarstern cruises:

SOUTHERN OCEAN: 3 specs, cruise PS69, ANT-XXIII/8, stn 604-1, Elephant Island, 61°20.52ʹ S, 55°09.72ʹ W to 61°20.11ʹ S, 55°07.26ʹ W, 286–407 m, bottom trawl, 19 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert (RBINS, INV. 132980); 1 spec. with a true posterodorsal bump on second body segment, cruise PS69, ANT-XXIII/8, stn 604-1, Elephant Island, 61°20.52ʹ S, 55°09.72ʹ W to 61°20.11ʹ S, 55°07.26ʹ W, 286–407 m, bottom trawl, 19 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert (RBINS, INV. 122555); 2 specs, cruise PS69, ANT-XXIII/8, stn 608-1, Elephant Island, 61°11.34ʹ S, 54°43.17ʹ W to 61°11.80ʹ S, 54°40.05ʹ W, 284–293 m, bottom trawl, 20 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert (RBINS, INV. 132982); 1 spec., cruise PS69, ANT-XXIII/8, stn 610-1, Elephant Island, 60°58.59ʹ S, 55°08.39ʹ W to 60°58.05ʹ S, 55°05.00ʹ W, 287–311 m, bottom trawl, 21 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert (RBINS, INV. 122550); 2 specs, cruise PS69, ANT-XXIII/8, stn 614-3/4/5, Elephant Island, 60°52.37ʹ S, 55°29.80ʹ W to 60°52.71ʹ S, 55°27.83ʹ W, 248–265 m, a lot of epifauna, Rauschert dredge and Agassiz trawl, 22 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert (RBINS, INV. 132984); 2 juvs, cruise PS69, ANT-XXIII/8, stn 614-3/4/5, Elephant Island, 60°52.37ʹ S, 55°29.80ʹ W to 60°52.71ʹ S, 55°27.83ʹ W, 248–265 m, a lot of epifauna, Rauschert dredge and Agassiz trawl, 22 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert (RBINS, INV. 122554); 1 spec., alcohol-fixed, cruise PS69, ANT-XXIII/8, stn 624-3, Elephant Island, Agassiz trawl, 61°00.23ʹ S, 55°58.53ʹ W to 61°00.76ʹ S, 55°59.20ʹ W, 287–319 m, 23 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert (RBINS, INV. 122479); 4 specs, cruise PS69, ANT-XXIII/8, stn 627-1, Elephant Island, 60°59.00ʹ S, 55°42.36ʹ W to 60°57.62ʹ S, 55°40.19ʹ W, 90–102 m, bottom trawl, 24 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert (RBINS, INV. 132979); 5 specs, cruise PS69, ANT-XXIII/8, stn 642-1, Elephant Island, 61°04.38ʹ S, 55°59.81ʹ W to 61°04.27ʹ S, 55°58.88ʹ W, 254 m, Agassiz trawl, 27 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert (RBINS, INV. 132981); 1 small spec., cruise PS69, ANT-XXIII/8, stn 642-2, Elephant Island, 61°04.28ʹ S, 55°58.93ʹ W to 61°04.24ʹ S, 55°59.27ʹ W, 255–277 m, Rauschert dredge, 27 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert (RBINS, INV. 122557); 2 specs, alcohol-fixed, cruise PS69, ANT-XXIII/8, stn 654-6, Elephant Island, 61°22.80ʹ S, 56°03.84ʹ W to 61°23.35ʹ S, 56°04.89ʹ W, 341–342 m, Agassiz trawl, 29 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert (RBINS, INV. 122480); 1 small spec., cruise PS69, ANT-XXIII/8, stn 654-6, Elephant Island, 61°22.80ʹ S, 56°03.84ʹ W to 61°23.35ʹ S, 56°04.89ʹ W, 341–342 m, Agassiz trawl, 29 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert (RBINS, INV. 122556); 2 ♀♀, cruise PS69, ANT-XXIII/8, stn 654-6, Elephant Island, 61°22.80ʹ S, 56°03.84ʹ W to 61°23.35ʹ S, 56°04.89ʹ W, 341–342 m, Agassiz trawl, 29 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert (RBINS, INV. 132983); 5 specs, cruise PS69, ANT-XXIII/8, stn 676-1, north of Livingstone Island, 62°11.06ʹ S, 60°47.49ʹ W to 62°09.65ʹ S, 60°49.56ʹ W, 418–472 m, bottom trawl, 2 Dec. 2007, coll. C. d’Udekem d’Acoz and H. Robert (RBINS, INV. 122544); 2 specs, cruise PS69, ANT-XXIII/8, stn 680-5, northeast of Livingstone Island, 62°23.37ʹ S, 61°25.58ʹ W 62°22.75ʹ S, 61°25.97ʹ W, 324–349 m, Agassiz trawl, 3 Jan. 2007, coll. C. d’Udekem d’Acoz and H. Robert (RBINS, INV. 122553); 1 ♀, specimen used for detailed illustrations, cruise PS81, ANT-XXIX/3, stn 193-8, Bransfield Strait, 62°43.73ʹ S, 57°29.04ʹ W to 62°43.80ʹ S, 57°29.40ʹ W, 426-431 m, 23 Feb. 2013, coll. C. d’Udekem d’Acoz and M. Verheye (RBINS, INV. 122956A) [extraction P36; Genbank nr, 28S: KU759680]; 3 ♀♀, cruise PS81, ANT- XXIX/3, stn 193-8, Bransfield Strait, 62°43.73ʹ S, 57°29.04ʹ W to 62°43.80ʹ S, 57°29.40ʹ W, 426-431 m, 23 Feb. 2013, coll. C. d’Udekem d’Acoz and M. Verheye (RBINS, INV. 122956B); 6 specs, cruise PS81, ANT-XXIX/3, stn 193-9, Bransfield Strait, 62°43.50ʹ S, 57°27.92ʹ W to 62°43.53ʹ S, 57°28.28ʹ W, 420–431 m, sponge bottom, 23 Feb. 2013, coll. C. d’Udekem d’Acoz and M. Verheye (RBINS, INV. 122961); 1 spec., cruise PS81, ANT-XXIX/3, stn 217-6, Bransfield Strait, 62°53.45ʹ S, 58°13.06ʹ W to 62°53.42ʹ S, 58°13.41ʹ W, 461–483 m, rich sponge bottom,Agassiz trawl, 2 Mar. 2013, coll. C. d’Udekem d’Acoz and M. Verheye (RBINS, INV. 122922B) [extraction P38; Genbank nr, 28S: KU759682].

Description

ROSTRUM. Long, reaching about tip of article 1 of peduncle of antenna 1 (teeth excluded), weakly curved, sharp-tipped in lateral view.

EYE. Very large, elliptic.

PEREION–PLEOSOME TOOTH PATTERN. Pereionite 1 without any trace of mid-dorsal tooth, with pair of very low non-carinate dorsolateral swellings; pereionite 2 nearly as broad as pereionite 1, with or without very small blunt-tipped mid-dorsal tooth or bump, and with pair of dorsolateral non-carinate swellings or very blunt teeth; pereionite 3 with medium-sized blunt-tipped mid-dorsal tooth and pair of small dorsolateral non-carinate blunt teeth; pereionite 3 to pleonite 2 with acute-tipped broad regularly curved mid-dorsal tooth (nearly same shape and size on all these segments) and pair of dorsolateral non-carinate acute-tipped teeth (pleonites 1–2 without second pair of dorsolateral teeth); pleonite 3 with dorsal sharp carina with very weak median notch (lobe anterior to notch very low) and obliquely produced posteriorly into an a broad acute and sharp triangular tooth, and pair of dorsolateral non-carinate acute-tipped teeth.

COXAE 1–3. Strongly carinate and distally sharp.

COXA 4. Anterodorsal and anteroventral border nearly straight, joined by low and blunt angular discontinuity, anterior angle not strongly projecting forward; ventral tooth very long and styliform; lateral carina with lateral well-developed and sharp triangular tooth pointing obliquely backwards.

COXA 5. With sharp and broadly triangular, carinate, lateral tooth pointing obliquely backwards.

COXA 6. With mid-sized, sharp and narrowly triangular, carinate, lateral tooth pointing obliquely backwards; posteroventral corner produced into a triangular tooth.

COXA 7. With ventral and posterior border straight, with posteroventral angle produced into a strong tooth.

EPIMERAL PLATES 1–3. Posteroventral angle produced into a very long styliform tooth.

UROSOME TOOTH PATTERN. Urosomite 1 with sharp triangular process pointing upwards; urosomite 2 without pair of small posterior dorsolateral teeth pointing upwards.

TELSON. Cleft on 0.25; tips of lobes rounded, slit fairly narrow.

PEDUNCLE OF ANTENNA 1. Article 1 with long lateral and medial teeth nearly reaching mid of article 2 (teeth excluded) and long ventral tooth reaching tip of article 2 (teeth excluded); article 2 with long lateral tooth nearly reaching tip of article 3 (tooth excluded), with medial tooth slightly overreaching article 3 (tooth excluded), with ventral tooth slightly overreaching tip of article 3 (tooth excluded); article 3 with very long ventral tooth, longer than article itself.

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

PEREIOPODS 5–7. Merus, carpus and propodus slender; basis of pereiopods 5–6 of normal width, with posteroproximal process rounded and strongly protruding, with posterodistal tooth strong; basis of pereiopod 7 very broad with posterodistal tooth sharp, followed more proximally by small concavity, directed posteriorly.

Colour pattern

Whitish with faint orange marks on body; peduncle of antenna 1 carpus and propodus of pereiopods and uropods also tinged with orange. Eyes reddish.

Body length

Up to 40 mm.

Distribution

Elephant Island to Bransfield Strait, 90–483 m (present data).

Remarks

The tip of the lateral tooth of coxa 4 is slightly damaged in the syntype of Epimeria similis illustrated by Chevreux (1913). This explains why the orientation of that tooth does not seem accurate on the drawings made by that author. Specimens of E. similis from Elephant Island look identical to specimens recorded further south, except for the absence of a mid-dorsal tooth on pereionite 2, which is either smooth or with a trace of bump. The difference is presumably size-related. Epimeria similis from Bransfield Strait and King George Island often reach a larger size than those of Elephant Island, and only the large ones have the extra tooth. So the specimens from Elephant Island are considered herein as small E. similis s. str.

The collecting station of the E. similis illustrated by Coleman (2007) on his figure 30 are 61°03.6ʹ S, 54°41.6ʹ W [Elephant Island]; 15 Dec. 1987, leg. Coleman, 358– 332 m, bottom trawl (Coleman pers. com.). This specimen appears to be a true E. similis. On the other hand, the specimen illustrated by a colour photograph on his plate 1, fig. e is presumably Epimeria acanthochelon sp. nov. (see discussion on that species).

It seems that E. similis and the similar and closely related E. acanthochelon sp. nov. have non-overlapping distributions. Epimeria similis was recorded from the South Shetland Islands and the tip of the Antarctic Peninsula. Epimeria acanthochelon sp. nov. was recorded on the Adélie Coast (supported by 28S rDNA) and on the eastern shelf of the Weddell Sea (identification based on morphology only). See key of Drakepimeria and account on E. acanthochelon sp. nov. for differences with E. similis.