Effect of seasonal variations on the histological structures of gonads in oreochromis niloticus (tilapia nilotica) =

Document Type : Original Articles

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Abstract

The morphological CHARacteristics of the tastes and the ovary of the nile tilapia (oreochromis niloticus) are presented. Testicular structure and spermatogenesis are described using histological techniques. The testes consist of capsule, seminiferous lobules (contain spermatogenic cell, sertoli cell), interstitial tissue (leydig cell) and duct system. The coexistence in the testicular lobules of spermatozoa and spermatogenic cells indicates that this species is able to perform continuous reproduction. Seasonal trend was noticed in the number of the spermatogenic cell produced over ayear period. The ovarian structure is also described using histological techniques. The ovary consist of capsule and ovarian follicles (chromatin-nucleolus, perinucleolus, cortical alveolar, vitellogenic and mature). Each follicle consists of oocyte and surrounding structure. Seasonal trend was noticed in the type of predominant follicles present over ayear period

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