Amphiakrops, Wittmann, 2024

Wittmann, Karl J., 2024, The Mysidae (Crustacea, Mysida) of the ANDEEP I-III expeditions to the Antarctic deep sea with the description of twelve new species, establishment of four new genera and with world-wide keys to the species of Erythropinae and Mysidellinae, European Journal of Taxonomy 940, pp. 1-180 : 109-110

Amphiakrops gen. nov.

urn:lsid:zoobank.org:act:90554F72-6514-4128-B01D-A0533B775212

Paramblyops bidigitatus -group – Murano 2002a: 35, table 1.

Type species

Amphiakrops brandtae gen. et sp. nov. by present designation.

Diagnosis

Eye rudiments without definite stalk; eyes set apart, not connected by membranous integument, both distal edges produced into tooth-like, non-sensory processes, no visual elements, no ocular papilla. Third segment of antennular trunk undivided (divided into two portions in Teratamblyops Murano, 2001 ). Bare lateral margin of antennal scale ending in a single, strong tooth; mesial margin setose all along. Three segments of antennal peduncle lined in a single plane. Clypeus with rostral process, if present, not strongly elongate. Thoracomeres and pleomeres normal. Thoracic endopod 2 not prehensile. Marsupium formed by three pairs of well-developed oostegites. Female pleopods representing setose rods with residual differentiation of pseudobranchial lobe. Male pleopods biramous, with well-developed sympod and multi-segmented exopod; endopod 1 short, unsegmented; endopods 2–5 long, multi-segmented; all endopods with setose pseudobranchial lobe; endopod 4 as far as known with modified setae. Both rami of uropods undivided, setose all around (with one spine in currently known species). Telson trapeziform, distally converging, terminally truncate. Spines densely set along distal portions of lateral margins. Terminal margin with pair of paramedian setae and 1–2 small spines, together flanked by several large spines.

Etymology

The genus name is a transliterated noun with Greek masculine ending, condensed from the Ancient Greek preposition ‘ἀμφί’ (‘on both sides’) with the adjective ‘άκρος’ (‘acute’) and the noun ‘ὤψ’ (‘eye’), referring to the tooth-like extensions on both sides of each eye rudiment.

For differences from related genera and for the inclusion of two species of Paramblyops , see ‘Discussion’ below.

Species included

– A. bidigitatus (W.M. Tattersall, 1911) comb. nov. (recombined from Paramblyops bidigitata W.M. Tattersall, 1911 ) from the NE Atlantic: Bay of Biscay, off Ireland, SW of Faroes, Iceland Basin, 44– 64° N, 3– 29° W, depth 976–2900 m (W.M. Tattersall 1911; Tattersall & Tattersall 1951; Mauchline 1982; Lagardère 1985; Petryashov 2014b; Astthorsson & Brattegard 2022)

– A. japonicus ( Murano, 1981) comb. nov. (recombined from Paramblyops japonica Murano, 1981 ) from the NW Pacific: E of Japan, on sea floor at a depth of 1690 m (plus 0–1250 m recorded with non-closing device), 33– 36° N, 141– 142° E ( Murano 1981)

– A. brandtae gen. et sp. nov. from the Southern Ocean: Weddell Sea, Drake Passage, South Sandwich Trench, 58– 65° S, 25– 61° W, depth 2086–2920 m