不同脂肪源饲料培育的大型溞对中华绒螯蟹仔蟹发育和变态的影响

Effects of cultured Daphnia magna by different lipid sources on development and metamorphosis of Chinese mitten crab Eriocheir sinensis from megalopa to juvenile crab

2003年5月20日至6月22日，研究了不同脂肪源饲料培育的大型潘对中华绒螯蟹发育和变态的影响。采用纯酵母（酵母组）、酵母添加10％豆油（豆油组）和酵母添加10％鱼油（鱼油组）三组饲料培养的大型潘作为大眼幼体发育到仔蟹Ⅳ期的生长和蜕壳的饵料。实验期间水温为室温，温度为20～24℃。结果表明，鱼油组培养的大型潘能显著地加速仔蟹发育阶段变态时间（缩短蜕皮周期），促进生长。其次为豆油组。酵母组最差。其加速变态的效果在仔蟹I期发育变态到Ⅱ期就显著表现出来。此外，鱼油组，豆油组与酵母组相比，相应仔蟹期的规格较大。脂肪酸组成分析显示，仔蟹脂肪酸的组成在一定程度上，反映了其摄食不同脂肪源饲料培育的大型滔的脂肪酸组成。鱼油组的仔蟹具有相对高的EPA，DHA和HUFA的百分组成，而豆油组培育的仔蟹由于大型潘中含有较高含量的C18：2，而致使仔蟹的C18：2具有最高含量。实验证实，饵料中高HUFA的含量，能显著促进仔蟹的生长和变态。PUFA，特别是C18：2对仔蟹变态和成活也有一定的促进作用。

The effects of reared Daphnia magna by different diets with various lipid sources as the live food on the metamorphosis, survival and growth of the Chinese mitten crab Eriocheir sinensis during the juvenile development stages from magalopa to juvenile crab four（Ca） were studied from May 20,2003 to June 22,2003. The mitten crabs with different development stages were divided into three experimental groups and fed on Daphnia magna reared by three different diets with various lipid sources, the first group fed on pure bread yeast （yeast group）, the second one fed on pure bread yeast with 10% soybean oil（soybean group） enrichment, the third one fed on pure bread yeast with 10% fish oil enrichment （fish oil group）, the water temperature during experiments is from 20 - 24 ℃. The results show that the juvenile crab with different development stages rearing with fish oil group food obtained the earlier metamorphosis, better survival and faster growth than those of the other two groups. The width of empty carapace of Ca （ juvenile crab three） fed on fish oil group food and soybean oil group food is bigger than those of crab fed on yeast group food. The analysis of lipid content and fatty acid composition of different stages of juvenile crab with different foods group suggested that the crab fatty acid compositions reflected the corresponding dietary composition. The crab fed on fish oil group food tended to accumulate more lipid and higher composition of DHA, EPA, HUFA than those of other two group food, and crab fed on soybean oil group food tended to accumulate highest C18：2n6. The higher composition of DHA, EPA, HUFA） or C18：2n6 in the food （D. magna） results in good survival, growth and metamorphosis of the mitten crab. So the results demonstrated the importance of dietary EPA, DHA in Chinese mitten crab juvenile development stages, which shortened the critical period of metamorphosis timing and enhanced survival and growth. Dietary content of PUFA, probably high 18：2n6 may also have a good result to enhance survival and metamorphosis timing and growth.