Seasonal histological and macroscopic changes in the gonads of Cheimerius nufar (Ehrenberg, 1820) (Sparidae: Pisces)

Abstract

Seasonal histological and macroscopic changes in the gonads of the hermaphroditic fish, Cheimerius nufar are described. The ovo-testis of the immature fish differentiates into either a functional ovary or a functional testis, with rudimentary tissue of the atrophied latent sex possibly present. Functional males and females reach maturity at ca. 340 mm total length and have a sex ratio of 1:2. The peak spawning period, early December to late January, correlates well with maximum sea temperatures and daylength. A revised classification system for the description of oocyte development, based on oogenetic and vitellogenetic changes, is also presented.