鹿児島県喜界島から得られた日本初記録のウミヘビ科フトミミズアナゴ（新称）Scolecenchelys laticaudata

抄録

Two specimens of the worm eel, Scolecenchelys laticaudata (Ogilby, 1897), collected from Kikai Island, Kagoshima Prefecture, Japan represent the first record of the species from Japan and the northernmost record of the Pacific Ocean. Although S. laticaudata is similar to S. aoki in the location of the dorsal-fin origin and vertebral counts, the former is distinguishable from the latter by its rounded snout (vs. acute), large head (head length 9.9–12% of total length vs. 7.6–10%), robust body (body depth at gill opening 2.9–4.0% of total length vs. 1.7–2.6%), mouth rictus edge not behind the posterior margin of the eye (vs. well behind), two postorbital pores (vs. three) and biserial upper-jaw teeth, even in small specimens (vs. uniserial). Scolecenchelys laticaudata most closely resembles S. gymnota in the head, trunk, tail proportions, post orbital pore count and number of teeth rows, but differs in having a rounded snout and robust body (vs. 1.7–2.9%), as well as in the position of the mouth rictus edge and numerous vertebral and lateral-line pore counts (total 136–142 vs. 118–135; preanal 55–58 vs. 47–52; lateral-line pores before anus 54–59 vs. 49–53). The new Japanese standard name, “Futo-mimizu-anago”, is proposed for the species.