The Effect of Abiotic Factors on Certain Biochemical Changes in Ovotestis of Snail Lymnaea acuminata: Intermediate Host of Trematode Diseases

Every month during the year 2006-2007, the fecundity, hatchability, survival and simultaneous measurement of total protein, free amino acid, nucleic acid levels were made in the ovotestis ofL. acuminata, with concomitant estimations of certain abiotic factors, viz. temperature, pH, dissolved oxygen and carbon dioxide both in control and test water. On the basis of these observations, it was noted that abiotic factors caused significant variation in the protein, amino acid and nucleic acid levels in control as well as tested water through out the year. A significant positive correlation (p<0.05) was observed between fecundity and dissolved oxygen / pH of water. On the contrary, a negative correlation was observed with dissolved C02 / temperature of water. There was a significant (P<0.01) positive correlation between total protein / free amino acid / nucleic acids and fecundity of snails. A maximum level of DNA (63.43|ug/mg) in the ovotestis of snail was noted in the month of May, when fecundity was maximum at 35°C temperature, 8.22 pH, 4.1 mg/1 dissolved oxygen, 9.0 mg/1 carbon dioxide. Maximum level of RNA (30.76 |ug/mg) was in the month of October, when fecundity (158.83 eggs/20 snail) and temperature, pH, dissolved oxygen and C02 were 158.83 egg/20 snail, 34°C, 8.45, 5.3 mg/1,7.5 mg/1, respectively. The protein (84.48 |ug/mg) and amino acid (46.11 |ug/mg) level were also maximum in the month of May and October, respectively. This study conclusively showed that abiotic factor significantly alter the reproductive capacity of snails with simultaneous biochemical changes in ovotestis of snail in different test water in each month of year.