Aetheliparis Stein, 2012, new genus

Aetheliparis new genus

Type species. Psednos rossi Chernova & Stein 2004

Diagnosis. Vertebrae 47 or fewer, dorsal rays 44 or fewer, anal fin rays 35 or fewer. Mouth and lower jaw vertical or angled posteriorly. Spine straight, not curved, body not humped. Coronal pore absent. Gill cavity enlarged, its opening far posterior, completely anterior to pectoral fin base. Branchiostegal rays six, prominent, elongated, dorsally curved but generally horizontally oriented. Pectoral fins far posterior to head, supracleithrum and or cleithrum elongated to support posterior location of pectoral girdle low on side of body. Pleural ribs absent.

Etymology. Aetheliparis, from the Greek, aethes-, strange, denoting the remarkable morphology of the head and pectoral girdle of the species of the genus, and liparis, the root of the family name.

Species. The new genus includes two species: A. rossi (Chernova & Stein) and A. taurocanis n. sp. The latter is from New Zealand waters (Fig. 1).

Distribution. North Atlantic (A. rossi) and South Pacific (A. taurocanis) at mesopelagic depths.

Comparisons. Designation of a new genus for these two mesopelagic species is warranted because they differ significantly from all other liparid genera. Aetheliparis is most similar to Psednos and Paraliparis in lacking a pelvic disk. However, it differs markedly from both (and all other liparid genera) in having a vertical or negatively angled mouth (unknown in any other liparid species), an elongated branchial cavity extended posteriorly (vs short and vertically oriented), branchiostegal rays long and largely horizontal (vs strongly curved and generally vertically oriented), the supracleithrum greatly elongated posteriorly to support the pectoral girdle which is located far behind the head by at least 1/3 SL and possibly more (vs immediately posterior to it and supported by a short supracleithrum), and the dorsal and anal fin origins and anus located far posteriorly (vs anteriorly).