水温、流量、发育时期及孵化密度对澳洲淡水龙虾受精卵离体孵化率的影响

Effects of Several Factors on inVitro Hatchability of Fertilized Eggs of Cherax quadricarinatus

【目的】通过研究水温、流量、受精卵发育时期和孵化密度等因子的变化对澳洲淡水龙虾受精卵离体孵化率影响,以确定澳洲淡水龙虾受精卵离体孵化最适条件因子。【方法】分别设计5个水温梯度、3个流量、3个发育时期及3个孵化密度进行澳洲淡水龙虾受精卵离体孵化试验。【结果】随着水温升高,受精卵孵化时间呈下降趋势;受精卵离体孵化率随着水温的上升呈先上升后下降的趋势,在水温28℃,澳洲淡水龙虾受精卵离体孵化率达最高,显著高于其他试验组(P<0.05),复眼色素形成初期受精卵发育至初孵仔虾的平均有效积温为9375℃·h。不同流量下澳洲淡水龙虾受精卵离体孵化率依次为5 L/min>2 L/min>8 L/min(P<0.05)。澳洲淡水龙虾受精卵发育至复眼色素形成初期和孵化准备期的孵化率显著高于前无节幼体期(P<0.05)。受精卵孵化密度为500粒/L和1000粒/L时,离体孵化率显著高于1500粒/L(P<0.05),但500粒/L和1000粒/L时离体孵化率差异不显著(P>0.05)。【结论】澳洲淡水龙虾受精卵离体孵化的适宜条件为:水温28℃,流量5 L/min,受精卵发育期为复眼色素形成初期,孵化密度为1000粒/L(每个槽的尺寸为长×宽×高为15 cm×9.7 cm×12 cm,水深3 cm±0.5 cm,体积约0.4 L)。

【Objective】This study was conducted to optimize the hatching conditions of Australian freshwater crayfish.【Method】Four single factor experiments were conducted to investigate the effects of water temperature,waterflow,development period and hatching density on in vitro hatching rate of fertilized eggs of Australian freshwater crayfish.【Result】The results showed that the incubation time decreased with the increase of water temperature,the highest in vitro hatching rate was observed at 28℃(P<0.05),the hatchability of fertilized eggs was significantly higher at 26℃and 30℃than that at 24℃and 32℃(P<0.05),the accumulative temperature was 9375℃·h.The in vitro hatching rate of fertilized eggs under different waterflow was 5 L/min>2 L/min>8 L/min(P<0.05);The hatching rate of fertilized eggs in the embryo with eye pigments and prepare-hatchling stage was significantly higher than that in the egg-nauplius stage(P<0.05);The hatching rate of fertilized eggs was significantly higher at density 500 eggs/L and 1000 eggs/L than that at density 1500 eggs/L(P<0.05),however,there was no significant difference in in vitro hatchability between 500 eggs/L and 1000 eggs/L(P>0.05).【Conclusion】In summary,the fertilized eggs of Australian freshwater crayfish were stripped in the embryo with eye pigments,at the density 1000 eggs/L,at water temperature 28℃and waterflow 5 L/min could obtain a higher hatching rate.