Abstract
Nine specimens of a clariid catfish, Clarias frtscus.which is new to Japan, were collected at Ishigaki Island, the southern Ryukyus.Characteristics of these specimens are described, with special reference to differences among Clarias fuscus. C.hatrachus.and C.macrocephalus.Variations of characters are investigated in28 specimens of Clarias fuscus from Japan.Formosa, and Philippines.The diploid chromosome number of the species is 56, and the karyotype is described.
