東シナ海から得られた日本初記録のウミヘビ科魚類(条鰭綱:ウナギ目)フチナシウミヘビ(新称)Pisodonophis sangjuensis

摘要

Five specimens (306.5-402.6 mm of total length) of the ophichthid eel, Pisodonophis sangjuensis Ji and Kim, 2011 (Actinopterygii: Anguilliformes), were collected from off Kagoshima Prefecture, Japanese waters of the East China Sea, during 2013-2014. They represent the first records of the species from Japanese waters, and the new standard Japanese name "Fuchinashi-umihebi is proposed for the species. Although arrangements of vomerine teeth of the present specimens differ from those of an illustration of the holotype given in the original description, it is inferred as an ontogenetic difference. Pisodonophis sangjuensis is similar to P. cancrivorus (Richardson, 1848) in having the dorsal-fin origin positioned a vertical through the middle of the pectoral fin, the presence of three preopercular pores, a dark margin on the cephalic sensory pores, and about 150 total vertebrae. However, the former can be distinguished from the latter by the upper-jaw length (27-32% of head length vs. 36-38% in the latter), the shape of snout (robust and blunt vs. sharp and pointed tip), the shape of teeth (conical with pointed tip vs. granular), coloration of its dorsal and anal fins (pale white, except for short posteriormost areas vs. dark brown to dark grayish margin), and the number of total vertebrae (143-153 vs. 153-164).