几种环境因子对不同发育阶段的泥螺Bullacta exarata的影响

SOME ENVIRONMENTAL FACTORS ON THE DIFFERENT DEVELOPMENT STAGES OF THE MUD SNAIL BULLACTA EXARATA

本文研究报告了几种环境因子对不同发育阶段泥螺的生存、生长的影响。泥螺为广温、广盐性种类，适温范围为－１．５－３３℃。适比重范围，低限为１．０１０，高限随其发育程度而不同。在海水酸碱度ｐＨ＝７－８条件下，存活率最高，生长最好。泥螺耐干露能力，随着个体生长，忍耐能力逐渐加强，其干露后死亡的体重消耗率，成螺约为６９％左右。

This paper reported out the growth and the survival rate of the mud snail Bullacta exatata(Philippi)in different development stages in some environmental factors.The mud snail belongs to eurytherm and euryhaline.The temperaturesuitable for its existence is-1.5°-33℃,the lowest of sea specific gravity for existence is 1. 010, the highest is differ in the different development stages .The best growth and the highest survival rate is in the pH value from 7 to 8 of the sea water.Along with the development,the tolerable ability of exposure to driness is increase.On an average, the rate of the body weight loss at death is about 69 percen