pH对龟足胚胎和幼虫发育的影响

Effects of pH on embryonic and larval development of Capitulum mitella Linnaeus

为探讨水体pH对龟足（Capitulum mitella）胚胎孵化和幼虫生长发育的影响,采用单因子实验的方法,在水温25-28℃条件下,研究了不同pH（5.0、5.5、6.0、6.5、7.0、7.5、8.0、8.5、9.0、9.5）对龟足胚胎的孵化时间、孵化率和幼虫存活率、变态率的影响。结果表明：pH为5.0时,胚胎不孵化;pH在5.5-9.5之间,龟足胚胎都能够有不同程度地孵化。pH在6.0-8.5之间,孵化时间最短,仅需6 d,其中pH在7.0时,孵化率最高。pH对累积孵化率的影响极显著（P〈0.01）。结合胚胎发育时间和孵化率两个指标,龟足胚胎最适的孵化pH为7.0-8.0。根据存活率和变态率,龟足幼虫生长发育的pH上限和下限分别是5.0和9.0;在pH5.5-8.5之间,龟足幼虫都可以不同程度地生长和变态,幼虫发育的最适pH范围是7.5-8.5。

Effects of pH（5.0,5.5,6.0,6.5,7.0,7.5,8.0,8.5,9.0 and 9.5） on the embryonic development and larval development of Capitulum mitella were investigated under controlled laboratory conditions.The pH affected significantly not only the development time and hatching rate of embryos but also the survival rate and metamorphosis rate of larvae.At pH 5.0,embryos of Capitulum mitella couldn＇t hatch,but at pH 5.5-9.5,it could hatch in different degrees.At pH 6.0-8.5,Capitulum mitella had the shortest development time（6 d）,and at pH 7.0,Capitulum mitella had the highest hatching rate.On the basis of development speed and hatching rate of embryos,the optimum pH for embryonic development was 7.0-8.0.Larvae could develop and metamorphose at pH 5.5-8.5,but when the pH was lower than 5.0 or higher than 9.0,it couldn＇t develop normally.According to larval survival rate and metamorphosis rate of Capitulum mitella,the optimum pH for larval development was 7.5-8.5.