Epimeria (Hoplepimeria) inermis, 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 : 84-88

publication ID	https://doi.org/ 10.5852/ejt.2017.359
publication LSID	lsid:zoobank.org:pub:703F4B1F-DFAD-47DD-AEA5-9E31A1921508
persistent identifier	https://treatment.plazi.org/id/4A5A879B-FFD5-6828-FE46-FC05CD2CFAF7
treatment provided by	Carolina
scientific name	Epimeria (Hoplepimeria) inermis
status	subgen. nov.

Treatment

Epimeria (Hoplepimeria) inermis View in CoL subgen. nov. Walker, 1903

Figs 159–184 View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig

Epimeria inermis Walker, 1903: 54 View in CoL , pl. 10 fig. 69.

Epimeria inermis View in CoL – K.H. Barnard 1930: 374 (in part); 1932: 173 (in part), fig. 104a. — Nicholls 1938: 95, fig. 50. — Gurjanova 1955: 198. — J.L. Barnard 1961: 103 (key). — McCain 1971: 161. — Bellan-Santini 1972: 223, plate 32. — De Broyer & Klages 1991: 165 (key). — Ren & Huang 1991: 262, fig. 48. — Wakabara & Serejo 1999: 642 (key). — Coleman 2007: 41, fig. 19a–b, colour plate 1c, map 10 (rhomb). — Lörz & Coleman 2009: unnumbered photographs on p. 17. — Lörz et al. 2011: 2, fig. 13 row 6 [holotype], table 3.

‘ Epimeria inermis View in CoL 2, 4, 5, 6’ – Rauschert & Arntz 2015: 61, pl. 54.

non ‘ Epimeria inermis View in CoL 1’ – Rauschert & Arntz 2015: 61, pl. 54 (= Epimeria (Metepimeria) acanthurus View in CoL

( Schellenberg, 1931)). non ‘ Epimeria inermis View in CoL 3’ – Rauschert & Arntz 2015: 61, pl. 54 (= Epimeria (Hoplepimeria) angelikae View in CoL

subgen. nov. Lörz & Linse in Lörz et al., 2011).

Type material

Holotype

British Antarctic Expedition 1898–1900, RV Southern Cross:

SOUTHERN OCEAN : ♀, Cape Adare , 51 m (28 fathoms) ( BMNH 1903.10.5.19 ).

Other material examined

RV Polarstern cruises:

SOUTHERN OCEAN: 2 specs, previously identified as E. georgiana , cruise PS39, ANT-XIII/3, EASIZ I, stn 11, GSN 4, eastern Weddell Sea, 73°22.60ʹ S, 21°10.60ʹ W to 73°23.00ʹ S, 21°12.90ʹ W, 333– 338 m, bottom trawl, 13 Feb. 1996, coll. C. De Broyer and G. Chapelle ( RBINS, INV. 132707); 1 juv., cruise PS39, ANT-XIII/3, EASIZ I, stn 11, GSN 4, eastern Weddell Sea, 73°22.60ʹ S, 21°10.60ʹ W to 73°23.00ʹ S, 21°12.90ʹ W, 333–338 m, bottom trawl, 13 feb. 1996, coll. C. De Broyer and G. Chapelle ( RBINS, INV. 132710); 9 specs, previously mixed with 1 E. xesta sp. nov., misidentified as E. georgiana and used for gut content analysis, cruise PS39, ANT-XIII/3, EASIZ I, stn 12, GSN 5, eastern Weddell Sea, 73°18.10ʹ S, 21°10.10ʹ W to 73°17.10ʹ S, 21°08.20ʹ W, 457–459 m, bottom trawl, 14 Feb. 1996, coll. C. De Broyer and G. Chapelle ( RBINS, INV. 132996); 1 spec., cruise PS39, ANT-XIII/3, EASIZ I, stn 17, GSN 10, eastern Weddell Sea, 73°18.00ʹ S, 21°09.90ʹ W to 73°19.10ʹ S, 21°14.90ʹ W, 465– 468 m, bottom trawl, 16 Feb. 1996, coll. C. De Broyer and G. Chapelle ( RBINS, INV. 132708); 1 spec., cruise PS39, ANT-XIII/3, EASIZ I, eastern Weddell Sea, station lost, specimen kept in aquarium, 27 Feb. 1996, coll. C. De Broyer and G. Chapelle ( RBINS, INV. 132684); 1 spec., cruise PS69, ANT- XXIII/8, stn 605-1, Elephant Island, 61°20.35ʹ S, 55°29.16ʹ W to 61°19.98ʹ S, 55°32.67ʹ W, 146– 151 m, bottom trawl, 19 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert ( RBINS, INV. 122513); 1 large spec., 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. 122520); 1 small spec., cruise PS69, ANT-XXIII/8, stn 609-6, Elephant Island, 61°08.58ʹ S, 54°31.86ʹ W to 61°08.58ʹ S, 54°31.86ʹ W, 437–442 m, Rauschert dredge, 21 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert ( RBINS, INV. 122486); 4 ♀♀, 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. 122512); 5 ♀♀, 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. 122511); 6 ♀♀, cruise PS69, ANT-XXIII/8, stn 654-7, Elephant Island, 61°23.37ʹ S, 56°04.35ʹ W to 61°23.94ʹ S, 56°03.79ʹ W, 318–345 m, Rauschert dredge, 29 Dec. 2006, coll. C. d’Udekem d’Acoz and H. Robert ( RBINS, INV. 122514); 1 spec., cruise PS71, ANT- XXIV/2, ANDEEP-SYSTCO, stn 48-1, eastern Weddell Sea, 70°23.94ʹ S, 8°19.14ʹ W to 70°23.89ʹ S, 8°18.67ʹ W, 595–602 m, bryozoan bottom (exceptional bryozoan diversity), Rauschert dredge, 12 Jan. 2008, coll. H. Robert ( RBINS, INV. 132954) [extraction I3; Genbank nr, COI: KU870847 View Materials , 28S: KU759624 View Materials ]; 2 small specs, cruise PS71, ANT-XXIV/2, ANDEEP-SYSTCO, stn 48-1, eastern Weddell Sea, 70°23.94ʹ S, 8°19.14ʹ W to 70°23.89ʹ S, 8°18.67ʹ W, 595–602 m, bryozoan bottom (exceptional bryozoan diversity), Rauschert dredge, 12 Jan. 2008, coll. H. Robert ( RBINS, INV. 122897); 1 small spec., cruise PS71, ANT-XXIV/2, ANDEEP-SYSTCO, stn 48-1, eastern Weddell Sea, 70°23.94ʹ S, 8°19.14ʹ W to 70°23.89ʹ S, 8°18.67ʹ W, 595–602 m, bryozoan bottom (exceptional bryozoan diversity), Agassiz trawl, 12 Jan. 2008, coll. H. Robert ( RBINS, INV. 122905); 1 large spec., cruise PS71, ANT- XXIV/2, ANDEEP-SYSTCO, stn 48-1, eastern Weddell Sea, 70°23.94ʹ S, 8°19.14ʹ W to 70°23.89ʹ S, 8°18.67ʹ W, 595–602 m, bryozoan bottom (exceptional bryozoan diversity), Agassiz trawl, 12 Jan. 2008, initially fixed in formalin, coll. H. Robert ( RBINS, INV. 132459); 1 spec., cruise PS77, ANT-XXVII/3, stn 281-1, eastern Weddell Sea, BENDEX area, 70°48.93ʹ S, 10°32.69ʹ W to 70°49.46ʹ S, 10°33.66ʹ W, 283 m, bottom trawl, 28 Mar. 2011, bottom trawl, coll. C. Havermans and H. Robert ( RBINS, INV. 132955) [extraction I11, Genbank nr, 28S: KU759613 View Materials ]; 1 ♀, cruise PS81, ANT-XXIX/3, stn 199- 4, Bransfield Strait, 62°57.22ʹ S, 58°14.60ʹ W to 62°57.33ʹ S, 58°14.95ʹ W, 325–339 m, non-muddy bottom (content of the net dominated by sponges; also small stones, Stylasteridae and crinoids) Agassiz trawl, 27 Feb. 2013, coll. C. d’Udekem d’Acoz and M. Verheye ( RBINS, INV. 132953) [extraction I18; Genbank nr, COI: KU870843 View Materials , 28S: KU759620 View Materials ]; 1 spec., cruise PS81, ANT-XXIX/3, stn 224-2, Bransfield Strait, 63°0.50ʹ S, 58°37.53ʹ W to 63°0.54ʹ S, 58°37.50ʹ W, 254–256 m, black sand, Rauschert dredge, 4 Mar. 2013, coll. C. d’Udekem d’Acoz and M. Verheye ( RBINS, INV. 122972); 1 ovigerous ♀, cruise PS81, ANT-XXIX/3, stn 224-3, Bransfield Strait, 63°0.53ʹ S, 58°35.67ʹ W to 63°0.58ʹ S, 58°36.11ʹ W, 257–261 m, mud, Agassiz trawl, 4 Mar. 2013 ( RBINS, INV. 122945A) [extraction ANT 45; Genbank nr, COI: KU870831 View Materials , 28S: KU759604 View Materials ]; 1 immature spec., cruise PS81, ANT-XXIX/3, stn 224-3, Bransfield Strait, 63°0.53ʹ S, 58°35.67ʹ W to 63°0.58ʹ S, 58°36.11ʹ W, 257–261 m, mud, Agassiz trawl, 4 Mar. 2013 ( RBINS, INV. 122945B); 1 spec., cruise PS81, ANT-XXIX/3, stn 227-2, Bransfield Strait, 62°55.83ʹ S, 58°41.09ʹ W to 62°55.76ʹ S, 58°41.46ʹ W, 562–564 m, mud, Agassiz trawl, 5 Mar. 2013 ( RBINS, INV. 122948) [extraction ANT 44, Genbank nr, COI: KU870830 View Materials , 28S: KU759603 View Materials ].

RV Marion Dufresne cruises:

SOUTHERN OCEAN:3specs,cruise MD42 (SIBEX),stn 22-CP73,Prydz Bay, 66°57ʹ25″S, 72°41ʹ25″E, depth missing [Google depth for that position: 533 m], 26 Jan. 1985, (MNHN-IU-2014-4261) (typed label).

RV Aurora Australis cruises:

SOUTHERN OCEAN: 1 ovigerous ♀, cruise CEAMARC, sample CEAMARC 971, stn 42EV167, Adélie Coast, 66°53ʹ22″ S, 142°38ʹ54″ E, 262–431 m, beam trawl, 28 Dec. 2007, coll. IPEV-AAD- MNHN (MNHN-IU-2014-4272) [extraction M1; Genbank nr, COI: KU870877 View Materials , 28S: KU759660 View Materials ]; 1 spec., cruise CEAMARC, sample CEAMARC 1317, stn 51AEV215, Adélie Coast, 66°44ʹ52″ S, 145°26ʹ40″ E, 525–553 m, beam trawl, 30 Dec. 2007, coll. IPEV-AAD-MNHN (MNHN-IU-2014-4274); 1 ♀, cruise CEAMARC, sample CEAMARC 2724, stn 71EV447, Adélie Coast, 66°24ʹ00″ S, 140°32ʹ21″ E, 683–791 m, beam trawl, 14 Jan. 2008, coll. IPEV-AAD-MNHN (MNHN-IU-2014-4338) [extraction M2; Genbank nr, COI: KU870886 View Materials , 28S: KU759669 View Materials ]; 3 specs, cruise CEAMARC, sample CEAMARC 3226, stn 20EV490, Adélie Coast, 66°00ʹ59″ S, 140°00ʹ02″ E, 189–196 m, beam trawl, 15 Jan. 2008, coll. IPEV-AAD-MNHN (MNHN-IU-2014-4346); 5 specs, cruise CEAMARC, sample CEAMARC 3532, stn 87EV524, Adélie Coast, 65°29ʹ29″ S, 139°18ʹ37″ E, 397–411 m, beam trawl, 17 Jan. 2008, coll. IPEV-AAD-MNHN (MNHN-IU-2014-4351); 5 very large specs, cruise CEAMARC, sample CEAMARC 3978, stn 36EV297, Adélie Coast, 66°20ʹ20″ S, 143°41ʹ08″ E, 552–573 m, beam trawl, 4 Jan. 2008, coll. IPEV-AAD-MNHN (MNHN-IU-2014-4328).

RV Seatruck, cruise REVOLTA I:

SOUTHERN OCEAN: 1 ovigerous ♀, stn REVO_020b, Collect_ID: 143, Field_ID: CE-000004560, Adélie Coast, 66°40ʹ30″ S, 139°55ʹ05″ E, 19–23 m, 15 Jan. 2010:, coll. M. Eléaume, L. Hemery and A. D’Hont, (MNHN-IU- 2009-2569) [extraction K3; Genbank nr, 28S: KU759642 View Materials ].

RV Seatruck, cruise REVOLTA II:

SOUTHERN OCEAN: 2 specs, stn REVO_091, Collect_ID: REVO_162, Adélie Coast, 66°41ʹ07″ S, 139°56ʹ41″ E, 33–34 m, 19 Jan. 2011, coll. N. Améziane, N. Bax, C. Gallut, A.C. Lautrédou and C. Robineau (MNHN-IU-2014-4308).

RV L’Astrolabe, cruise REVOLTA III:

SOUTHERN OCEAN: 1 spec., stn none (Dumont d’Urville Sea), Collect_ID: REVO_449, Adélie Coast, 66°38ʹ S, 140°42ʹ E to 66°38ʹ S, 140°40ʹ E, 718–729 m, mud, beam trawl, 20 Jan. 2012, coll. G. Lecointre, A. Dettaï, J. Lanshere, C. Gallut and C. Ozouf (MNHN-IU- 2009-2545); 1 large spec., stn none (Dumont d’Urville Sea), Collect_ID: REVO_449, Adélie Coast, 66°38ʹ S, 140°42ʹ E to 66°38ʹ S, 140°40ʹ E, 718–729 m, mud, beam trawl, 20 Jan. 2012, coll. G. Lecointre, A. Dettaï, J. Lanshere, C. Gallut and C. Ozouf (MNHN-IU- 2009-2584).

RV Seatruck, cruise REVOLTA III:

SOUTHERN OCEAN: 1 ovigerous ♀, stn REVO_032, Collect_ID: REVO_509, Field_ID: CE- 000002403, Adélie Coast, 66°39.306ʹ S, 140°01.635ʹ W to 66°39.370ʹ S, 140°01.686ʹ W, 72–100 m, beam trawl, 8 Feb. 2012, coll. G. Lecointre, A. Dettaï, J. Lanshere, C. Gallut and C. Ozouf, ( MNHN- IU- 2009-2531) [extraction K2; Genbank nr, 28S: KU759632 View Materials ].

Description

Description based on holotype. ROSTRUM. Medium-sized, reaching mid of article 2 of peduncle of antenna 1, anteriorly strongly curved, ventrally straight, acute-tipped in lateral view; blunt-tipped, broad and with borders scarcely convex in frontal view.

EYE. Medium-sized, elliptic.

PEREION–PLEOSOME TOOTH PATTERN. Pereionites 1–2 smooth; pereionite 3 with trace of carina and trace of posterodorsal bump; pereionite 4 to pleonite 3 with low and blunt mid-dorsal carina, which is strongly laterally compressed (especially the posterior ones); all these carinae with very weak median concavity, that of pleonite 3 with a second weak concavity and posteriorly forming a blunt squared angle.

COXAE 1–3. Weakly carinate and apically subacute.

COXA 4. Anterodorsal border nearly straight (very slightly concave), anteroventral border very weakly convex, these two borders being joined by blunt but distinct squared angle (anterior corner), which is distinctly projecting forward; ventral corner forming an obtuse angle (ventral projection moderately developed); lateral carina absent; posteroventral border straight.

COXA 5. Broad, with surface smooth, with posteroventral corner forming a blunt-tipped projection, weakly expanded laterally, forming a blunt squared angle in dorsal view.

COXA 6. With posteroventral corner forming a blunt squared angle, with very low projection arising from its surface (forming a very low indistinct lobe in dorsal view).

COXA 7. Posterior and ventral border weakly convex, joined by blunt squared angle.

EPIMERAL PLATES 1–3. Posteroventral angle: rounded 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 rounded dorsal process; urosomite 3 with dorsolateral borders distinctly concave.

TELSON. Cleft on 0.035; tips of lobes obtusely triangular and very blunt, notch very broadly V-shaped.

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

PEREIOPODS 5–7. Merus, carpus and propodus of medium width; dactylus medium-sized; basis of pereiopods 5–6 of normal width, with posteroproximal process present, forming a very low rounded projection in pereiopod 5, forming a well-developed asymmetrical rounded lobe in pereiopod 6; with posterodistal corner rounded, small, projecting forward; basis of pereiopod 7 broad with posterior border weakly convex, with distinct but very shallow notch on distal 0.8, forming a blunt-tipped extremely obtuse angle, with posterodistal corner rounded, small, projecting ventrally.

Colour pattern

Holotype red ( Walker 1903). The colour of specimens from the Antarctic Peninsula, the Weddell Sea and Adélie Coast is very variable: uniformly orange, orange red with a finely mottled/doted pattern, whitish with sparse small mottling or body divided between white zones and red zones with a finely mottled/doted pattern; eyes always reddish.

Body length

36 mm (holotype). The holotype is one of the largest specimens examined.

Distribution

Elephant Island, tip of Antarctic Peninsula, eastern shelf of the Weddell Sea, Davis Sea, Adélie Coast, western Ross Sea; 33– 791 m.

Remarks

Examination of the holotype of Epimeria inermis (Ross Sea) revealed morphological differences with the specimens from the South Shetland Islands, the Antarctic Peninsula, the eastern Weddell Sea and Adélie Coast. The most striking difference is the telson, which is scarcely emarginate in the holotype of E. inermis , whilst it exhibits an acutely triangular V-shaped notch in all other specimens examined. However, the notch is also quite small in the specimen from the Adélie Coast illustrated by Bellan- Santini (1972). The rostrum is also shorter and more distinctly curved in the holotype of E. inermis . The dorsal carina of pereionite 4 is posteriorly slightly projecting upwards, which is not the case in other specimens. The ventral part of coxa 4 is less developed, forming a blunt-tipped obtuse angle instead of a sharp squared angle. The posterior notch of the basis of pereiopod 7 is a bit shallower. Finally, the process of urosomite 1 is more obtuse.

Molecular data would be needed to investigate if the specimens from the Ross Sea (topotypical E. inermis ) are conspecific with or distinct from specimens from other seas. On the other hand, the COI corrected mean distance (GTR+G+I) between the haplotypes from the Scotia Arc area and the Adélie Coast is 1.3%. This distance is much higher than intraspecific distances observed in other Epimeria species (0–0.5%; table 2 in Verheye et al. 2016a). However, additional intraspecific sampling might increase these values. It is unclear from the molecular data if these two clades are distinct species or populations of the same widespread species ( Verheye et al. 2016a). As the single specimen from the eastern Weddell Sea was only sequenced for 28S, it is possible that the more variable COI would show some differentiation with the haplotypes from the Adélie Coast and Scotia Arc area as well. But as no morphological differences were observed between the specimens from the three regions (compare Figs 167–172 View Fig View Fig View Fig View Fig View Fig View Fig : Bransfield Strait and Figs 173–184 View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig : eastern Weddell Sea and Adélie Coast), they are provisionally considered as conspecifics.

The record of E. inermis from the Falkland Islands by K.H. Barnard (1930) seems very dubious. It is possibly based on E. (Metepimeria) acanthurus ( Schellenberg, 1931) , which is the only Magellanic Epimeria species known to date.