A new species of deep-sea synaphobranchid eel, Haptenchelys parviocularis (Anguilliformes: Synaphobranchidae), from Japan

A new synaphobranchid eel Haptenchelys parviocularis is described on the basis of 15 specimens (467–840 mm in total length) collected off the Pacific coast of southern Japan, in depths of 4,093–4,866 m. The new species is distinguishable from its single congener, Haptenchelys texis Robins and Martin in Robins and Robins 1976, in having the following combination of characters: total vertebrae 127–137, caudal vertebrae 90–98; snout short, length 42.5–53.1 % upper-jaw length; eye much smaller than gill-slit aperture, diameter 37.5–59.4 % gill-slit length and 11.8–16.9 % upper-jaw length; eye positioned closer to middle of mouth gape (postorbital length-to gape 23.5–32.5 % head length and 40.5–50.9 % upper-jaw length); gill-slit aperture wide (15.8–22.1 % head length and 24.8–35.7 % upper-jaw length), orientation oblique to body axis.