Spermatogenesis and the stages of maturation in the male cichlid fish Tilapia mossambica

Cyclical changes in the histology of the testis of Tilapia mossambica are described. The immature virgin testis contains primary germ cells and primary spermatogonia lying within a body of connective tissue. Just before spawning the testis is packed with sperm but cells at all stages of spermatogenesis are also present. After spawning the unexpelled spermatozoa undergo phagocytosis. No quiescent period during spermatogenesis has been observed though there are two periods of increased spermatogenetic activities. The stages of maturation of the testis are also reported. Five stages are distinguished.