Investigation of the development of egg cells in Mırmır (Lithognathus mormyrus, Linneaus 1758) fish

In this study, weights of striped sea bream used in study were changed between 49.95 and 450 gr. The minimum weight of fish was captured in December while the maximum fish were caught in March. In addition to weight data, total lengths were varied between 16 and 31 cm. According to obtained data from the analyses, the heterochronal spawning was determined in striped sea bream related with the asynchronous development of oocyte. It is determined that non-maturated gonad included previtellogenic oocytes. It is estimated that transition of gonads to this stage was recorded from the September to April for 7 months. During this stage, it is observed that gonads were not thin and have granular structure in terms of macroscopic and also their colors were changed between light yellow and beige. Besides, it is detected that oocytes in the early vitellogenic stage were observed in the April. From the July, maturation, spawning and post-spawning stages were observed synchronously in the gonads. Vitellogenesis stage which is the marker of the maturation and migration of the germinal vesicle which is the marker of the spawning and also atretic eggs which are usually observed after spawning were observed from the May. These changes which are closely related with the asynchronous oocyte development have been observed during the 4 months from May to August. During this stage, granular structures of gonads were clearly observed by the macroscopic approach. According to overall evaluations of data, it is clearly determined that striped sea bream is a protandric hermaphrodite and also heterocheronal species. Keywords: Striped sea bream, Lithognathus mormyrus, gonad, histology