温度对匙吻鲟胚胎与仔鱼发育的影响

研究不同温度下匙吻鲟(Polyodon spathula)的胚胎与仔鱼发育。结果表明,26℃时,匙吻鲟胚胎发育到大卵黄栓期全部死亡;在15～24℃范围内,胚胎均可孵化出膜,孵化时间与温度呈极显著的负相关关系(P<0.01)。胚胎发育的最适温度范围为18～22℃,最佳温度为20℃,生物学零度为12.30℃。卵黄囊期仔鱼历时随温度的升高而缩短。在16～22℃范围内,温度对卵黄囊期仔鱼生长的影响极显著(P<0.01),22～24℃影响不显著(P<0.05)。在22～26℃范围内,仔鱼生长的差异不显著(P<0.05),成活率低,且畸形率极显著地高于16～20℃(P<0.01)。匙吻鲟仔鱼早期发育的最适温度范围为18～20℃,温度过高是造成仔鱼畸形率增加的主要原因之一。

Effects of Temperature on Embryonic and Larvae Development of Polyodon spathula

The embryonic and larvae development of Polyodon spathula at different temperatures were investigated.The results showed that all the embryos died at the stage of big yolk plug at 26 ℃,and the embryos could be hatched at temperature between 15 and 24 ℃.There was significant obvious negative correlation between hatching time and temperature (P < 0.01).The most proper temperature for embryonic development was 18-22 ℃,and the most optimal temperature was 20 ℃,the biological zero was found to be 12.30 ℃.The period of yolk-sac larva stage was shortened with the temperature rising.At temperature of 16-22 ℃,temperature had great significant effects on the growth of larvae at yolk-sac larva stage (P < 0.01),but there was no effect of temperature on the growth of larvae when larvae began to be fed (P < 0.05).There was no difference of larvae growth from 22 to 26 ℃ (P < 0.05),and the survival rates were lower and the abnormality rates were significantly higher than 16-20 ℃ (P < 0.01).Overhigh temperature was one of the main reasons which cause the increase of abnormality rate of larvae,and the most proper temperature for early rearing of larvae was 18-20 ℃