Correlative changes in the Leydig's cells and male secondary sexual characters (SSC) in a freshwater fish Mystus (M) vittatus.

The study of testicular steroidogenic tissue in the freshwater fish Mystus (M) vittatus has been made by employing histochemical techniques to localize lipids. The Leydig's cells are steroidogenic. Their functional significance has been correlated with secondary sexual characters (SSC). The SSC have been found to follow a clear cut testicular cycle. The development of SSC is reflected by the abundance, numerical variations, size difference, hypertrophy and hyperplasia of the interstitial Leydig's cells. Functional identity of Sertoli cells in the development of SSC seems doubtful.