Epimeria (Verheye et al., 2016)

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 : 65-67

Subgenus Epimeria Costa in Hope, 1851

Gammarellus Herbst, 1793: 106 –115 (in part); type species: Gammarus homari Fabricius, 1779 [currently Gammarellus homari ( Fabricius, 1779) ].

Vertumnus White, 1847: 89 ; type species: Vertumnus cranchii Leach’s manuscript name; nomen nudum.

Vertumnus White, 1850a: 97 [+ pl. 16 figs 3–5 illustrating Leach’s specimens, as Acanthonotus testudo ] (real identity of the specimens: Epimeria cornigera ( Fabricius, 1779) , not Pereionotus testudo (Montagu, 1808)) ; Vertumnus White, 1850 = preoccupied and invalid objective synonym of Epimeria Costa in Hope, 1851 (see remarks below).

Epimeria Costa in Hope, 1851: 24, 46; type species: Epimeria tricristata Costa in Hope, 1851: 46 (= Gammarus corniger Fabricius, 1779: 383 ).

Gammarus – Fabricius 1779: 383 (in part). — H. Milne Edwards, 1840: 42–55 (in part).

Vertumnus – White 1850b: 51. — Spence Bate & Westwood 1862: 231. — Norman 1869: 280.

Acanthonotus – White 1850a: 97, pl. 16 figs 3–5; 1850b: 51 (in part); White 1857: 177. — Gosse 1855: 139, 142. — Spence Bate 1857: 141; 1862: 120. — Spence Bate & Westwood 1862: 231. — Carus 1885: 410.

Epimeria – Costa 1857: 175, 197. — Spence Bate 1862: 153–154. — Boeck 1871: 185 (105 on reprints); 1876: 232. — Stebbing 1888: 877–878 (ubi syn.); 1906: 321. — G.O. Sars 1893: 363 –364. — Chevreux & Fage 1925: 190–191. — Lincoln 1979: 434.

Acanthonotosoma [sic] – Della Valle 1893: 674, in part (ubi syn.).

Amphithoë – M. Sars 1859: 130–143 (in part).

Acanthosoma – Boeck 1861: 665–666 (in part); 1869: 410 (in part).

Acanthonotosoma [sic] – Della Valle 1893: 674, in part (ubi syn.).

non Gammarus Fabricius, 1775: 418 ; type species: Cancer pulex Linnaeus, 1758 . non Acanthonotus Bloch, 1797: 112–114 , pl. 431; type species: Acanthonotus nasus Bloch, 1797 ;

objective synonym of Notacanthus Bloch, 1788: 278 (type species: Notacanthus chemnitzii Bloch,

1788) ( Pisces). non Acanthonotus Cuvier, 1800 : table 4; nomen nudum ( Pisces). non Acanthonotus Goldfuss, 1809: 308 ; objective synonym of Echidna Cuvier, 1797: 143 (Mammalia) . non Acanthonotus Gray, 1830 : pl. 85, fig. 1; type species: Silurus (Acanthonotus) Cuvieri Gray, 1830

(Pisces). non Acanthonotus Swainson & Richardson, 1832: 168 ; nomen nudum ( Aves). non Acanthonotus Ross, 1835 : xc; type species: Acanthonotus cristatus Ross, 1835 . non Ampithöe Leach, 1814: 432 ; type genus: Cancer rubricatus Montagu, 1808 . non Vertumnus Otto, 1823: 294 , pl. 41 fig. 1; type species: Vertumnus thetidicola Otto, 1823 (Trematoda) . non Acanthosoma Curtis, 1824 : unnumbered pagina referring to plate 20 ( Hemiptera ). non Acanthosoma Ross, 1835: 91 ; type species: Acanthosoma hystrix Ross, 1835 . non Acanthonotozoma Boeck, 1876: 237 ; type species: Acanthonotus cristatus Ross, 1835 . non Amphithoë – Latreille, 1816: 470 (misspelling for Ampithöe Leach, 1814 ). non Vertumnus – Goës 1866: 522. — Boeck 1871: 99. — Miers 1877: 135. — G.O. Sars 1883: 26 (all

three = Acanthonotozoma Boeck, 1876 ).

Type species

Epimeria tricristata Costa in Hope, 1851 (= Gammarus corniger Fabricius, 1779 ). Good illustrated descriptions: G.O. Sars (1893); Chevreux & Fage (1925); Lincoln (1979); Ledoyer (1993).

Description

Body opaque, with teguments strongly calcified. Rostrum medium-sized to long. Ventral lobe of head rounded to angular. Eyes present, not conical. Pleonites 1–3 and at least pereionites 6–7 (sometimes all pereionites) with low mid-dorsal dentate carina projecting backwards and one pair of dorsolateral much smaller carinate teeth (sometimes duplicate or triplicate on pleonites) or carina. Pereionites 1–7 sometimes with low carina or trace of protrusion just above connection with coxa. Coxae 1–4 subacute to blunt-tipped. Coxae 1–3 sharply keeled along their axis. Coxa 4 with sharp carina starting at ventral tip of coxa and terminating at posterior tip of coxa; this never bears a tooth projecting laterally; posteroventral border concave. Coxae 5–6 with strong sharp tooth projecting backwards. Mid of posterior border of epimeral plates 1–3 or 1–2 produced into a tooth. Dorsal process of urosomite 1 produced into a tooth, which can be directed upwards or backwards. Urosomite 2 without pair of small teeth pointing upwards. Lateral borders of urosomite 3 posteriorly blunt or bluntly angular, not produced into a sharp tooth. Telson weekly bilobed. Eyes present, large, rounded or pyriform. Peduncle of antenna 1 without teeth. Mandible with molar process triturative. Lower lip with narrow (V-shaped) hypopharyngeal gap. Palp of maxilliped with 4 articles. Gnathopods of normal size, with carpus and propodus of medium slenderness, with palm obliquely transverse (gnathopods subcheliform); propodus not expanded distally; posterior border of dactylus lined by row of small oblique slender teeth. Basis of pereiopods 5 very slender, quadrate, without posteroproximal protrusion and with trace of posterodistal tooth projecting posteriorly (or posterodistal corner angulate). Basis of pereiopod 6 fairly slender, elliptic or narrowly ovate (then broad part proximal), without posteroproximal rounded protrusion and without posterodistal tooth projecting posteriorly, without posterodistal angle: the basis is distally tapering and at its apex it has the same width as the ischium, hence there is not projecting angularity. basis of pereiopod 7 fairly narrow to fairly broad, with posterior border proximally slightly convex and distally slightly concave, with posterodistal corner rounded or with a tooth projecting posteriorly. Dactylus of pereiopods 5–7 short. Benthic.

Body length

The maximum body length recorded in species of the subgenus Epimeria ranges between 9 and 40 mm (G.O. Sars 1893).

Ecology.

Benthic, 50 m ( Lincoln 1979) to 3028 m ( Jones et al. 2003).

Distribution

European western and northern seas, Mediterranean and South Africa.

Remarks

As eight Antarctic and sub-Antarctic subgenera are erected herein for Epimeria , the extralimital (Atlantic) type subgenus Epimeria had to be redefined. It is cautiously restricted herein to the following species: Epimeria cornigera ( Fabricius, 1779) , Epimeria loricata G.O. Sars, 1879 , Epimeria parasitica (M. Sars, 1858) , Epimeria tuberculata G.O. Sars, 1893 , an undescribed Northwest European species discovered by Beerman & Raupach (2015), and an undescribed Mediterranean deepsea species, of which specimens are deposited in the Museum of Verona (J. Beerman, pers. com.).