Gonochorism and seasonal variations in the gonads of the labrid Symphodus (Crenilabrus) ocellatus (Forsskål)

A histological study of gonadal organization of 354 Symphodus ocellatus caught in the Bay of Naples from June 1985 to December 1986 demonstrated the absence of sexual inversion in this species. Four phases of gonadal development, related to the seasonal cycle, are described. During the reproductive period the ovaries showed the asynchrony in oocyte development that is typical of serial spawners. The testes of three types of males present in this species (territorial, satellite and sneaker males) were examined: the only difference found was in the gonadal growth pattern during the reproductive period.