Effect of safe concentrations of some pesticides on testicular recrudescence in the freshwater murrel, Channa punctatus (Bl): a morphological study.

The effects of safe concentrations of fenitrothion 50% E.C., an organophosphate, and carbofuran 3% G, a carbamate, on testicular recrudescence of Channa punctatus during the maturing, prespawning, and spawning phases (15th April through 12th August, 1980) of the annual reproductive cycle have been studied. The results reveal that compared to the carbofuran treatment, the fenitrothion treatment was more effective in lowering testicular weights. Furthermore, the carbofuran treatment delayed the formation of spermatids and sperm, since their occurrence in the testes was observed at 90 days of exposure, but at 60 days of exposure in the control fish. The fenitrothion treatment not only delayed the formation of spermatids, but also arrested the formation of sperm, since most of the spermatids had undergone necrosis. The exposure for 120 days to safe concentrations of carbofuran/fenitrothion also resulted in the necrosis of spermatogonia and spermatocytes, which led to their gradual loss. As such, the lobules completely devoid of the spermatogenetic stages were observed in the testes of the treated fish. The occurrence of such empty lobules, however, was relatively greater in the fenitrothion-treated fish. The formation of the collagenous capsules around the necrotic germ cells was also observed in the treated fish testes. The interstitial (Leydig) cells were in the involuted condition in the treated fish testes, but active in the control fish.