Comparative study of morpho-histology of gonads of three teleost fishes.

1. In the present paper comparative study of morphohistology of gonads of 3 teleost fishes has been made. 2. The gonads are unpaired in Notopterus notopterus and paired in Nandus nandus and Colisa fasciatus. 3. The testis in Notopterus notopterus is flat structure and is situated ventrolaterally. In Nandus nandus the testes are paired elongated and slightly flattened structures while they are paired threadlike structures in Colisa fasciatus. 4. Histologically the testis consists of lobules filled with various stages of germ cells, such as primary and secondary spermatocytes, spermatids and sperms. 5. The testis can be differentiated into anterior and middle functional regions and the posterior non=functional region in the case of Notopterus notopterus while in Nandus nandus and Colisa fasciatus no such differentiation could be found. 6. The ovary is somewhat oval unpaired structure in Notopterus notopterus. In Nandus nandus ovaries are paired, elongated organ taper anteriorly while the ovaries are paired and triangular in Colisa fasciatus. 7. The histological structure of the ovary in all the 3 fishes represents the generalised teleostean structure. 8. The cystovarian condition of gonads are present in all the 3 fishes, Notoperus notopterus, Colisa fasciatus and Nandus nandus.