GONADAL DIFFERENTIATION AND THE MODE OF SEXUALITY IN COBITIS-TAENIA (TELEOSTEI, COBITIDAE)

Gonadal anatomy and development and patterns of development were studied to provide information about the mode of sexuality in Cobitis taenia (Teleostei: Cobitidae). Histological examination of gonads in developing fry showed that the two gonadal anlagen remain paired in males whereas in females they fused to form a single ovary. Few specimens of different ages and size were found with testes containing small numbers of small oocytes. Females grew faster than males; consequently, females were larger than males of the same age. Histological analysis and growth rates indicate that this is a gonochoristic species with a few males containing a few oocytes in their testes.