温度对泥蚶胚胎发育、幼体生长发育及变态的影响

Effect of Temperature upon Embryonic and Larval Development and Metamorphosis of Mud Clam (Tegillarca granosa)

用广西防城港海区２～３龄平均体重１０ 克／只～１２ 克／只的泥蚶作为亲贝，对泥蚶胚胎发育、幼体生长发育及变态与温度的关系进行试验研究； 试验温度为１９℃、２１℃、２３℃、２５℃、２７℃、２９℃、３１℃、３３℃。试验用水为沙滤海水， 比重１．０１４～１．０２０， ｐＨ值８．０～８．２。结果表明， 胚胎发育最适温度为２５℃～３１℃， 由此温度带求得的胚胎发育温度系数Ｑ１０ 为２．０５。在高低极端温度下， 胚胎发育畸形而死亡。幼体生长发育与温度的关系呈Ｌｏｇｉｔｉｃ曲线关系， 即２５℃～３１℃时， 幼体生长速率随温度升高而加快； 在极端温度下， 生长速率下降。在２３℃～３１℃， 即使没有附着基质， 幼体也能正常变态， 而１８℃以下时， 幼体不能变态而逐渐死亡。温度高于３１℃时， 幼体虽然能变态， 但死亡率高 （８０％ ～９０％ ）。

Experiments on the effect of temperature upon the embryonic and larval developments and larval metamorphosis of mud clam (Tegillarca granosa) were conducted with a test set of temperature being 19℃,21℃,23℃,25℃,27℃,29℃,31℃ and 33℃,in which the fertilized eggs were obtained through inducing the parent clams collected from the sea area along Fangcheng Harbour in the coast of Guangxi,aged 2~3 years with average individual weight of 10 g~ 12g,and the sea water used in the nursing was percolated through fine sand,the specific gravity being 1 014～1 020,pH 8 0～8 2.The results showed that the optimum temperature for embryonic development ranged from 25℃ to 31℃ by which the temperature coefficient Q 10 was caculated to be 2 05, and in extreme high and low temperature upon the larval growth followed Logistic distribution,i.e.,in the range of 25℃ to 31℃ the larval growth increased with increasing temperature,and in extreme temperature the larval growth was curved down in an obvious extent.Besides,the settling larvae could normally metamorphose within 23℃ to 31℃ even if no substrate was provided with,but did not metamorphose bellow 18℃ and died with time on.Although the settling larvae could metamorphose above 31℃,their mortality was high from 80% to 90%.