Hoplostethus Cuvier, 1829

Su, Yo, Lin, Hsiu-Chin & Ho, Hsuan-Ching, 2023, New records of two roughy fish species of Hoplostethus and a confirmed record of H. crassispinus Kotlyar, 1980 (Trachichthyiformes, Trachichthyidae) from Taiwan, ZooKeys 1149, pp. 85-101 : 85

Hoplostethus Cuvier, 1829

Hoplostethus Cuvier in Cuvier and Valenciennes 1829: 469 (type species: Hoplostethus mediterraneus Cuvier in Cuvier and Valenciennes 1829).

Korsogaster Parr, 1933: 9 (type species: Korsogaster nanus = Hoplostethus mediterraneus ).

Remarks.

Hoplostethus differs from other genera of Trachichthyidae in having the following combination of characters: body depth at dorsal-fin origin>40% SL; anus situated in front of anal-fin origin; dorsal-fin spines progressively longer posteriorly and longest at last spine; lateral-line scales distinctly larger than adjacent body scales, ca 2-3 times in size; light organ absent; and vomer usually without teeth ( Kotlyar 1996; Su et al. 2022).

Kotlyar (1986) divided Hoplostethus into four subgenera, Hoplostethus Aulohoplostethus , Hoplostethus Hoplostethus , Hoplostethus Leiogaster , and Hoplostethus Macrohoplostethus , by their numbers of dorsal-fin soft rays, pyloric caeca, and total vertebrae, coloration of pectoral fin, simple or branched pyloric caeca, and the presence of stritationed area on body. Among those subgenera, the subgenus Hoplostethus Hoplostethus is distinguished from other subgenera in having dorsal-fin soft rays 12-14 (vs 15-19 in Macrohoplostethus ), total vertebrae 25-26 (vs 29-30 in Macrohoplostethus ), pyloric caeca <50, simple and unbranched (vs>60, branched in Macrohoplostethus ), pectoral fin pale (vs black in Leiogaster ), and body without stritationed area (vs present in Aulohoplostethus ).

Among the 30 valid species in Hoplostethus , one species is recognized under Aulohoplostethus , 19 under Hoplostethus , eight under Leiogaster , and two under Macrohoplostethus , respectively.