Abstract
Gaussia princeps (Scott, 1894) (Copepoda : Calanoida : Metridinidae) is redescribed from the Indo-Pacific region on the basis of two adult females, one adult male, and the fifth copepodid stage of both sexes and compared with the holotype from the Gulf of Guinea. The specimens of G. princeps from the Indo-Pacific region showed no remarkable differences from the holotype. The morphological differences from its two congeners are also discussed. The genital compound somite of the female of G. princeps carries paired gonopores and copulatory pores located antero- and postero-ventrally, respectively, without distinct seminal receptacles ; this arrangement differs from those of other genera of the family Metridinidae. Present and previous data indicate that G. princeps is widely distributed in the mesopelagic zone of the oceans throughout the tropical to temperate regions, but there are some morphological evidences that the southeastern pacific population represents a distinct species.
