太平洋初記録のカマス科魚類Sphyraena arabiansisヤシャカマス（新称）と本種の標徴に関する新知見，およびS. barracudaオニカマスとの形態比較

抄録

Five large specimens (648.5–1162.9 mm standard length) of Sphyraena arabiansis Abdussamad and Retheesh in Abdussamad et al., 2015, previously known only from Lakshadweep, southeastern Arabian Sea, Indian Ocean, but recently collected from southern Japan (Kanagawa, Miyazaki, and Kagoshima prefectures) and off the south coast of New Caledonia, represent the first records of S. arabiansis from the Pacific Ocean. Sphyraena arabiansis is very similar to S. barracuda Edwards, 1771, both species sharing dark lateral body bars not extending onto the abdomen, whitish upper and lower caudal-fin tips, a pair of lobes on the caudal-fin central margin, and slightly elongated posteriormost rays of the second dorsal and anal fins. A re-assessment of currently recognized diagnostic characters of S. arabiansis confirmed scale row counts, branchiostegal membrane coloration, the presence or absence of body blotches, and location of body bars as valid for separating the two species. In addition, interorbital width and maxilla position distinguish between the species in specimens > 800 mm SL and 280 mm SL, respectively. Newly recognized diagnostic characters of S. arabiansis include numbers of total lateral-line scales, and upper and lower preopercular scale rows, and caudal-peduncle length. Revised diagnoses are given for S. arabiansis and S. barracuda and the new standard Japanese name ‘‘Yasha-kamasu’’ proposed for the former.