螺蛳投放量对中华绒螯蟹规格、产量和成活率的影响

研究了螺蛳投放量对池塘生态养殖的中华绒螯蟹平均育成规格、产量和成活率的影响.结果表明,中华绒螯蟹产量(Z)与螺蛳投放量(x)的关系为:Z=528.138+0.228x-0.000029x~2(R~2=0.959)(P＜0.05);中华绒螯蟹规格(Y)与螺蛳投放量(x)的关系为:Y=155.368+0.014x-0.0000017x~2(R~2=0.934)(P＜0.05);中华绒螯蟹成活率与螺蛳投放量的关系为:L=52.208+0.018x-0.0000023x~2(R~2=0.957)(P＜0.05).中华绒螯蟹池塘生态养殖中螺蛳最佳投放量为4500 kg/hm~2.

Effects of Snails Feeding Rates on Size, Yield and Survival of Chinese Mitten Crab Eriocheir sinensis

Juvenile (140 individuals/kg) Chinese mitten crab Eriocheir sinensis were randomly stocked into seven ponds of each 0.67 hm~2 with depth of 1.5 m at Cangxi 2814 fish farm in Gaochun county at a rate of 6000 ind/hm~2, and fed snails with feeding rate of 750, 1070, 2250, 4500, 5440, 5630 and 6750 kg/hm~2 to evaluate the effects of feeding rates on size, yield and survival of the crab. The test ponds were also polycultured with freshwater shrimp (Macrobrachium japonicum), mandarinfish (Siniperca chuatsi) and a few silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis) juveniles. The results showed that the relationship between the crab yield (Z) and snail amounts (x) was expressed as Z=528.138+0.228x-0.000029x~2 (R~2=0.959) (P<0.05);the relationship between the crab size (Y) and snail amount (x) was expressed as Y=155.368+0.014x-0.0000017x~2(R~2=0.934)(P<0.05);the relationship between the crab survival (L) and snail feeding rate (x) was equated as L=52.208+0.018x-0.0000023x~2(R~2=0.957)(P<0.05). The optimal snail feeding rate was suggested to be 4500 kg/hm~2.