Identification of the Commercially Important Oreosomatid Fish (Zeiformes: Teleostei) of the Emperor Seamounts, with Comments on Diagnostic Characters of the Species

An oreosomatid of the genus Allocyttus McCulloch, 1914 is fished commercially on Emperor Seamounts. However, species’ identity uncertain, as taxonomy species seas around Japan, where names verrucosus Gilchrist, 1906 (type locality: off South Africa) and A. folletti Myers, 1960 California) have both been used. From its anticipated susceptibility to over-exploitation, it urgent establish correct taxonomic facilitate effective management measures. Meristics, morphometrics scale characters specimens from Seamounts Japan agreed well with data holotype differed those verrucosus, confirming that represent folletti. Oreosomatids reported western North Pacific in literature were identified present study historical references, thought be distinguished by following characters: more dorsal- anal- spines+rays (36–42 vs. 33–38 31–35 27–33 respectively), total vertebrae (37–41 34–38), greater numbers enlarged scales (S-DFB) anal-fin base (S-AFB) (31–42 26–31, 29–37 25–28 spines margin S-DFB S-AFB (up 7–12 3–6), a shorter preanal-fin length (53.8–63.6% 64.8–83.7% SL), longer caudal peduncle (10.4–15.6% 6.1–10.2% head (32.9–40.4% 38.5–48.4% cycloid mid-side body (vs. ctenoid). Available indicate reaches up 537 mm SL, larger than ca. 325 SL). slow growth longevity, concern raised regarding over-exploitation.