Review of the Monacanthid Fish Genus Pervagor, with Descriptions of Two New Species

The monacanthid fishes of the genus Pervagor Whitley inhabit shallow tropical and subtropical seas of the Indo-West Pacific region. They are closely related to members of the genus Acreichthys, differing mainly in squamation, dentition, and vertebral counts.

Eight members of the genus are recognized in this review: P. alternans (eastern Australia, Lord Howe Island, New Caledonia, and the Marshall Islands), P. aspricaudus (Indo-West Pacific), P. janthinosoma (Indo-West Pacific), P. marginalis n. sp. (Marquesas and Line Islands), P. melanocephalus (Western Pacific), P. nigrolineatus (Philippines, Vietnam, Palau, Indonesia, and New Guinea), P. randalli n. sp. (Red Sea and Gulf of Aden), and P. spilosoma (Hawaiian and Johnston Islands).

P. marginalis differs from related members of the genus by the prominent black terminal band on its caudal fin, while P. randalli has a deeper body (1.9-2.1 in SL versus 2.1-2.5). P. nigrolineatus can be separated from the other species by the broad attachment of its ventral flap to the pelvic fin rudiment (not obviously attached in the remaining species). Material identified in the past as P. melanocephalus is here shown to represent 6 species. In addition, of 4 species described from prejuvenile material, only one (P. alternans) is here considered valid.

A detailed description of the genus is presented; full descriptions are provided for the 2 new species and diagnoses are presented for the remaining 6 species. Remarks on distribution and nomenclature are also included. All species are illustrated in color, while some diagnostic features are depicted by black and white photographs and scanning electron micrographs.