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)

关键词:  温度  泥蚶  胚胎发育  幼体生长  变态

Key words:  Temperature  mud clam (Tegillarca granosa)  embryonic development  larval growth  metamorphosis

摘要:

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%)。

Abstract:

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 Q₁₀ 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%.