不同饵料和饥饿对魁蚶幼虫生长和存活的影响

Effects of diet and starvation on growth and survival of Scapharca broughtonii larvae

在水温23.2—24.0℃,盐度29.5—30.0条件下,研究了5种单胞藻饵料和饥饿对魁蚶浮游幼虫生长与存活的影响。投喂不同饵料试验中,球等鞭金藻与4种单胞藻混合投喂试验组幼虫的特定生长率、眼点幼虫比例和壳长均显著高于单一投喂试验组,其中球等鞭金藻与小球藻混合投喂的效果最好;投喂单一饵料试验中,球等鞭金藻组幼虫的生长、眼点幼虫比例与存活率显著高于其它试验组。在饥饿试验中,不同饥饿天数条件下幼虫的存活率差异不显著;生长方面,饥饿1—2d较短时间与一直投喂对照组的幼虫相比较,特定生长率、眼点幼虫比例、壳长的差异不显著,但随着饥饿时间延长,幼虫的生长变慢且眼点幼虫比例下降,一直饥饿情况下幼虫的生长基本停滞。研究结果可以为魁蚶人工苗种繁育技术的改进提供参考依据。

Effects of diet and starvation on growth and survival of Scapharca broughtonii larvae were studied in two experiments by feeding the larvae with different algae diets and by starving the larvae for different periods of time.Ten days old larvae of S.broughtonii were fed with five different marine microalgae species,singly and in various mixtures.Both faster growth and higher eyespot larvae ratio were found in diets of Isochrysis galbana mixed with other four single species than in those of single species.Growth of the mixtures tested was in the order of 50% I.galbana/50% Chlorella sp.50% I.galbana/50% Platymonas subcordiformis50% I.galbana /50% Chaetoceros muelleri50% I.galbana/50% Nitzschia closterium.Of the single species diets,best growth and survival was observed in larvae fed with I.galbana,and which was similar to those of larvae fede with the mixture of 50% I.galbana / 50% Nitzschia closterium.At 23.2—24.0 ℃,larvae of S.broughtonii were deprived of food for various days to study the growth compensation from the outset of experiment.The results showed that starvation had significant effects on growth,though S.broughtonii larvae could survive long feeding delays.These results suggested that S.broughtonii larvae had the abiliity to survive ＇starvation＇ using alternative sources of energy.It also showed that growth,survival and metamorphosis of S.broughtonii were affected by many factors besides food quality and quantity.