不同饵料、密度和池底对锯缘青蟹大眼幼体蜕皮变态的影响

Effects of Diets,Densities and Substrata on Metamorphosis Rate to Postlarvae of Scylla serrata Megalopae

实验观察了不同饵料、池底、密度对锯缘青蟹大眼幼体蜕皮变态率和残杀率的影响.实验结果表明:投喂裸腹蚤时,大眼幼体蜕皮变态率最高,3种池底大眼幼体蜕皮变态率平均为 78.1%,残杀率最低平均为 11.4%;海泥池底大眼幼体蜕皮变态率最高,投喂3种饵料的大眼幼体蜕皮变态率平均为84.8%,残杀率最低平均为7.6%;裸腹蚤是青蟹大眼幼体培育适宜的饵料,而海泥则是大眼幼体变态适宜的池底.不同培育密度对青蟹大眼幼体蜕皮变态率和残杀率的实验结果表明:当大眼幼体的培育密度为3 尾/dm3 时,其蜕皮变态率最高,而残杀率与大眼幼体培育密度的关系不明确.

Effects of different dietary,densities and substrata on metamorphosis rate and cannibalistic rate from protozoea 1 (PZ1) to postlarvae 1(PL1) stages of Scylla serrata megalopae were studied in two separate experiments.In the first experiment,three dietary:Monia mongolica,minced meat of Ruditapes philippinaram which filted through mesh and haima 0 shrimp stuff and three substrata:sea mud,sand and cement were investigated.It showed that the metamorphosis rate of megalopae was higher when it was fed Monia mongolica than those were fed the other two diets and the average value of metamorphosis rate was 78.1% while the cannibalistic rate of megalopae was lower when it was fed Monia mongolica than those were fed the other two diets and the average value of cannibalistic rate was 11.4%.In the experiment of the substrata effecting on metamorphosis rate and cannibalistic rate of megalopae,the average value of metamorphosis rate was 84.8% when its substratum was sea mud,higher than the other two substrata and the average value of cannibalistic rate was 7.6% when its substratum was sea mud,lower than the other two substrata.So Monia mongolica was the optimum dietary for megalopae survival and metamorphosis,and sea mud was the optimal substratum for megalopae development.The second experiment studied six density level (2~7 ind/dm^3 ) of two groups which one dietary was Monia mongolica and the substratum was sea mud and the other dietary was minced meat and the substratum was cement.The two groups both showed that when the density of Scylla serrata protozoea 1 (PZ1) was 3 ind/dm, the metamorphosis rate was highest but the relationship between cannibalistic rate and megalopae density was still dubious.