Validity of the Cottid Species Stelgistrum mororane Transferred to the Genus Icelus (Actinopterygii: Perciformes: Cottoidei), with Confirmed Records of Stelgistrum stejnegeri from Japanese Waters

Abstract

Stelgistrum mororane Jordan and Seale, 1906, previously synonymized with Stelgistrum stejnegeri Jordan and Gilbert, 1898, is here redescribed as a valid species of the genus Icelus. Contrary to the original description, the holotype of S. mororane has palatine teeth, which are diagnostic of Icelus but absent in Stelgistrum. Icelus mororanis comb. nov. is distinguished from all other species of Icelus by the following combination of characters: body relatively short; parietal spine undeveloped; subocular and supraocular spines absent; scales absent on cheek, between dorsal scale row and lateral line, and below lateral line except at pectoral axilla; small and simple cirrus present on upper rim of eye; two pairs of nuchal cirri present; and four saddles present on dorsolateral surface of body. Additionally, seven specimens of Stelgistrum stejnegeri collected from the Pacific coast of eastern Hokkaido are described, representing the first confirmed records of this species in Japanese waters.