Impaired spermatogenesis in arsenic treated freshwater fish, Colisa fasciatus (Bl. and Sch.).

The testicular architecture of Colisa fasciatus was studied after 15 and 30 days of exposure to 14.0 or 2.0 mg/l arsenic(III) oxide. Marked alterations occurred at 14.0 mg/l after 30 days of treatment, while 2.0 mg/l (the concentration in Lake Chilwa) produced little change. In addition to the degenerative changes in the lobules, the interstitial Leydig cells (steroid-secreting cells) underwent significant reduction (P less than 0.01) in diameter. Varying degrees of necrosis and pyknosis suggested reduced secretory levels. Such changes may be correlated with the corresponding altered spermatogenesis.