P.K. Saxena

Effect of safe concentrations of some pesticides on ovarian recrudescence in the freshwater murrel, Channa punctatus (Bl.): A quantitative study

The effects of safe concentrations of carbofuran 3% G (5 ppm) and fenitrothion 30% E.C. (1.5 ppm) on ovarian recrudescence of Channa punctatus during the maturing, prespawning, and spawning phases (mid-April through mid-August) of the annual reproduction cycle were studied. The results reveal that, compared to carbofuran treatment, fenitrothion was more effective not only in lowering ovarian weights, but also in retarding the growth of previtellogenic (stage I) oocytes into vitellogenic (stage II) and yolky (stage III) oocytes. In addition, more previtellogenic and vitellogenic oocytes underwent atresia in fenitrothion-treated fish and only atretic oocytes were observed in the ovaries of these fish after 120 days of exposure. The fenitrothion treatment also caused a significant decline in the diameter of stage III oocytes, and in the number of nucleoli in stage I oocytes.

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.

Effect of some pesticides on in-vitro lipid and protein synthesis by the liver of the freshwater teleost, Channa punctatus (Bl.)

In vitro incorporation of (14)C-glucose/acetate into lipids and (14)C-leucine into proteins by the liver of Channa punctatus, exposed to safe application rate (SAR) and sublethal (SL) concentrations of malathion and carbaryl for 30 days (mid-February to mid-March) during the preparatory phase of the reproductive cycle, declined more in the fish exposed to SL concentrations than to SAR concentrations of the pesticides. The decline in incorporation was more marked in the malathion-exposed fish, than in those exposed to was more marked in the malathion-exposed fish, than in those exposed to carbaryl. Hence, malathion is considered more toxic than carbaryl in inhibiting the de-novo synthesis of lipids and proteins by the liver.

Effect of safe application rate (SAR) concentrations of some biocides on the gonads of the fresh water murrel, Channa punctatus (Bl.)--a biochemical study.

The effect of safe application rate (SAR) concentrations of fenitrothion 50% EC--an organo-phosphate and carbofuran 3% G--a carbamate on the gonads (ovaries/testes) of Channa punctatus was studied for 120 days (mid-April through mid-August) extending over the preparatory, prespawning, and spawning phases of annual reproductive cycle. The studies have revealed that the levels of total proteins, RNA, total lipids, and ascorbic acid decreased, while those of the cholesterol and the phospholipids increased following exposure to the two biocides. Furthermore, it was observed that in both treatments the decline in the levels of total total proteins, RNA, total lipids, and ascorbic acid was relatively more marked in the testes than in the ovaries. On the contrary, increase in the levels of cholesterol was relatively more in the ovaries, while increase in the levels of phospholipids was more in the testes in both treatments. The results suggest that the decrease/increase in the levels of the above-mentioned biochemical parameters was more in the fenitrothion treatment than in the carbofuran treatment and, therefore, may be considered relatively more toxic to this species.

Effect of vegetable oil factory effluent on the gonads of a freshwater teleost, Heteropneustes fossilis (Bl.) —A biochemical study

The effects of three sublethal concentrations (5,10,15% v/v) of vegetable oil factory effluent on biochemical changes in the gonads (ovaries/testes) of a freshwater teleost were studied. The results reveal a significant decline in the total lipid, cholesterol, phospholipid, and glycerine levels, but an increase in the free fatty acid levels, both in the ovaries and the testes of H. fossilis, following 150 days (mid-January through mid-June) of exposure to 10% and 15% concentrations of the effluent. This decrease/increase in the biochemical parameters was more or less dependent on the concentration of the effluent. The functional significance of any decrease/increase in the biochemical parameter(s) has been discussed.

Protein-bound iodine levels in the blood plasma of freshwater teleost, Channa punctatus (bl.) exposed to subtoxic pesticide concentrations

The effect of subtoxic concentrations (SC) of carbofuran 3% granules (G), a carbamate (5 ppm) and fenitrothion 50% emulsifiable concentrate (EC), an organophosphate (1.5 ppm) on protein-bound iodine (PBI) levels in the blood plasma of Channa punctatus were studied. Exposure to fenitrothion caused more decline in PBI levels than did carbofuran exposure.