A NEW GENUS AND SPECIES OF GEMPYLIDAE (PISCES : PERCIFORMES) FROM TONGA RIDGE

Abstract

During the research cruise of R.V. kaiyo Maru, which; the junior author (EF) joined around the Tonga Ridge area in the South Pacific, in 1977, a number of gempylid fish were caught in one haul of an otter trawl out of five hauls. This gempylid first seemed to be a second species of the monotypic genus Thyrsitops, because it has a similar appearance and counts to those of Thyrsitops lepidopoides. ?There are. some morphometric differences between the species:. our gempylid has a semifusiform and robust body, and T. lepidopoides has a much. more compressed and slender body; . Careful study revealed that the gempylid species obtained from .the Tonga Ridge is referable to a new genus and new species and that it has both gempylid and scombrid characteristics as discussed later.This species could be a key species in considering interrelationships between Gempylidae and 1Scombridae. Therefore, osteologicaL features are described in detail.