Abstract: Laboratory studies with Radix swinhoei and Bellamya aeruginosa show that R. swinhoei is tolerent toward low pH, its value being3.96 for LC₅₀ during 96 hours. When pHvalue is below 5.0, freshwater pulmonate snails produce less cocoons, their hatching period is longer, and the growth of Young snails is slower. At 35th and 45th day of growth, the growth rate of young B. aeruginosa is respectively 1.21 and 1.07% at low pH, and only 0.18 and 0.29％ at pH5.0, pH5.5 has no significant effect on freshwater-pulmonate snails, and pH3 induces their death.

Key words: Freshwater snail, Acidic water, Growth, Reproduction