Histological Investigation of Gonad Development of Chalcalburnus Tarichi (P., 1811)

Abstract

In this study, gonad development of Chalcalburnus tarichi, an anadromus, endemic fish species of the Lake Van and its inlets was histologically investigated. During oogenesis, six different development phases were histologically identified: chromatin-nucleolus, perinuclear, cortical alveolar, vitellogenic, ripening and ovulation phases. The diameters of oocytes were determined between 31 to 957 μm until the ovulation phase. According to the investigated sepcimens, vitellogenic phase started onward October and first ovulation was taken place in May-June 36 months and older females. It was found that some unspawned ova remained and formed atretic follicles in ovary after ovulation. Three different development phases were observed during spermatogenesis in testes: as unripened, ripening and ripened. Sperms started to form onward December and were released in May-June by 36 months and older males.