几种环境因子对梨形环棱螺的影响

本文报导了腹足类软体动物梨形环棱螺对水温环境因子十分敏感，螺的生长速度和产仔数量随着水温的变化呈正比例的加快和增加，或减缓以至暂时停止生长和产仔；试验结果表明pH值在4．0～9．4都能正常生存，喜偏酸性环境，最适范围为6．0～7．8；螺有较强的耐旱性，当失水率超过30％，开始死亡；96小时半致死浓度Lc502．28pH和10．80pH；当污染区全氮含量达到5．53％时没有梨形环棱螺存在，水域全氮含量不高于3．6％时，均能正常生活，该螺耐污性很强，能栖息于多污性和中污性水域。

THE INFLUENCE OF ENVIRONMENTAL FACTORS ON BELLAMYA PURIFICATE

This paper reported that Bellamya purificate was highly sensitive to environmental factors. The growth speed and spawning number would increase when the water temperature raised. The experiment showed that Bellamya purthcate could live normally when pH value was 4.0~9. 4, but the optimum value was 6. 0~7. 8. Bellamya purificate has strong ability to anti-dry. Only the losing ratio of water is over 30% would cause to die.When the total nitrogen content is over 5.53%, it will find nothing of Bellamya purificate,but they can live normally when the total nitrogen content is not higher than 3. 6%. Bellamya purificate can live in high polluted and middle polluted water regions.