鹿児島県甑島列島から得られた北限記録のヨウジウオ科魚類Solegnathus (Solegnathus) lettiensis Bleeker, 1860シンカイスミツキヨウジ（新称）

抄録

The pipehorse genus Solegnathus Swaison, 1839 is divided into two subgenera, Solegnathus Swaison, 1839 (superior trunk ridge discontinuous, with superior tail ridge) and Runcinatus Whitley, 1929 (ridges continuous), the former including Solegnathus (Solegnathus) hardwickii (Gray, 1830), S. (S.) lettiensis Bleeker, 1860, S. (S.) spinosissimus (Günther, 1870), and S. (S.) robustus McCulloch, 1911, and the latter, S. (Runcinatus) dunckeri Whitley, 1927. Of these five species, only S. (S.) hardwickii and S. (S.) lettiensis, have been recorded to date from Japanese waters, the latter being known from only two specimens [259.6 mm and 284.6 mm total length (TL)], both reported from the middle of the Okinawa Trough, southern East China Sea in 1978. However, a single specimen (KAUM–I. 182558, 367.0 mm TL) of S. (S.) lettiensis was found on a beach on Kamikoshiki-shima Island, Koshiki Islands, northern East China Sea, Kagoshima Prefecture, Japan in December 2022, probably a discarded bycatch from a deepwater bottom trawl fishery operating off the island. The specimen was characterized by having the superior trunk ridge discontinuous, with a superior tail ridge; opercular membrane without bony side platelets; body surface mainly tuberculate; length of dorsal-fin base 1.41 in head length; 23 trunk rings; and 74 total rings, and its identification confirmed after comparison with the two previously-collected specimens (above). The former, representing the second Japanese record and northernmost record of S. (S.) lettiensis, is described herein in detail, and the new standard Japanese name “Shinkai-sumitsuki-yoji” proposed for the species.