微藻饵料对紫海胆浮游幼体生长及存活影响的研究

文章采用湛江叉鞭金藻(Dicrateria zhanjiangensis)、纤细角毛藻(Chaetoceros gracilis)、绿色巴夫藻(Pavlova viridis)、扁藻(Platymonas subcordiformis)、小球藻(Chlorella vulgaris)及混合藻(金藻和角毛藻1∶1混合)投喂紫海胆(Anthocidaris crassispina),研究了微藻饵料对紫海胆浮游幼体生长发育的影响。结果表明,不同饵料对紫海胆浮游幼体生长发育的效果有差异,金藻是最佳饵料品种,角毛藻次之,其后分别为巴夫藻、小球藻和混合藻,扁藻不适于作为紫海胆浮游幼体的开口饵料。就饵料种类而言,金藻作为紫海胆浮游幼体饵料的成活率可达(23.12±1.8)%,显著高于其他单胞藻类(P<0.05)。就发育速度而言,以角毛藻和金藻混合喂食的海胆浮游幼体整体发育速度最快,幼体平均体长为(885.25±30.49)μm,显著高于其他5种处理(P<0.05);投喂巴夫藻的浮游幼体前期生长较慢,体长为(337.98±24.56)μm,后期较其他单胞藻类生长快,体长可达(580±32.95)μm,适宜作为紫海胆浮游幼体后期饵料。

Effects of dietary microalgae on growth and survival of larval development of sea urchin(Anthocidaris crassispina)

To investigate the growth and survival of sea urchin(Anthocidaris crassispina)larvae,we fed six microalgal dietsDicrateria zhanjiangensis,Chaetoceros gracilis,Pavlova viridis,Platymonas subcordiformis,Chlorella vulgaris,and mixture of C.gracilis and D.zhanjiangensis(1∶1)].The results show that different diets had different effects on the growth and development of the planktonic larvae of sea urchin.D.zhanjiangensis was the optimal microalgal diet.C.gracilis was the second,and then were P.viridis,C.vulgari,and mixture of C.gracilis and D.zhanjiangensis.However,P.subcordiformis was not suitable to be used as the opening bait for sea urchin larvae rearing.In terms of baits,D.zhanjiangensis was the best,since the survival rate of the larvae could reach(23.12±1.8)%,significantly higher than those of other unicellular algae(P<0.05).In terms of growth rate,mixture of C.gracilis and D.zhanjiangensis was the best,since the average length of the larvae could reach(885.25±30.49)μm,significantly higher than those of the other five treatments(P<0.05).The growth of the larvae fed with P.viridis was slow at early stage with body length of(337.98±24.56)μm,but it grew faster than the other unicellular algae at later stage with body length of(580±32.95)μm,so P.viridis is the suitable bait for planktonic larvae of A.crassispina at later stage.