Eurythenes gryllus.— Barnard, 1961: 35, in part, figs. 6–7.
Eurythenes thurstoni Stoddart & Lowry, 2004: 451, figs. 16–20.— Senna, 2009: 86 (table).— Quadra et al., 2014: 376, figs. 2–3.
Material examined. None.
Holotype and type locality. Australia, Tasman Sea, SE of Twofold Bay, New South Wales, FRV Kapala, stn K 77 - 19 -03, 37 ° 24 ’S 150 ° 30 ’E to 37 ° 28 ’S 150 ° 33 ’E, 550 m over bottom depth 3658 m, midwater trawl, 0 1.11. 1977, K. Graham, female 33 mm, with 18 juveniles in brood pouch (AM P 62435).
Diagnosis. Body not keeled. Pleonite 3 anteriorly not notched as in the gryllus -complex. Anterodorsal margin of head forming an upturned ridge (not observed in other species). Anterior lobe of head acute. Gnathopod 1 with basis very narrow, 3.8 x as long as wide, with palm of propodus protruding. Gnathopod 2 with coxa narrow and rounded ventrally, with propodus narrow, about 3.6 x as long as wide, not expanded, with palm very strongly projecting. Pereopod 3 with coxa very elongate, 2.5 x as long as wide. Coxa 4 with junction between ventral and posteroventral borders indistinct. Pereopod 7 with very long basis, 1.85 x as long as wide, with maximal width on proximal 0.25, with very elongate distal lobe (narrowing distally), 0.23 x as long as total length of basis, with propodus short (not longer than merus).
Description. See Stoddart & Lowry (2004).
Size. Up to 46 mm but most commonly not longer than 35 mm (Stoddart & Lowry 2004).
Distribution and depth range. South Atlantic (Quadra et al. 2014), Australia, Indonesia, Loyalty Islands Basin, Wallis and Futuna Islands, Tonga, Tasman Sea, South Tasmania, New Zealand, Gulf of Mexico, Guadeloupe, 550–1960 m, exceptionally as shallow as 128 m (Stoddart & Lowry 2004). Barnard (1961) records E. thurstoni under the name E. gryllus at much deeper (abyssal) stations (Stoddart & Lowry 2004), but it is possible that they were mesopelagic or upper bathypelagic specimens caught when the trawl was hauled up.
Biology. The species is a scavenger, which often enters baited traps. It is frequently captured in midwater trawls (Stoddart & Lowry 2004) suggesting a more pelagic life style than the Eurythenes of the gryllus -complex.