隐蔽所对不同生长阶段克氏原螯虾生长的影响

将体质量0.527 g(幼虾)和6.100 g(亚成体虾)的克氏原螯虾饲养在底面积为113 cm^2 、高为12 cm的圆形塑料盒中,一组放入内径为1.9 cm的PVC管作为隐蔽所为隐蔽组,以不放PVC管为对照组,其他条件同隐蔽组,定期测量各组克氏原螯虾的体长、体质量增长量、存活率和蜕壳率等指标,研究隐蔽所对不同规格克氏原螯虾生长的影响。2个月的饲养结果显示,试验第1个月隐蔽组幼虾组体长增长、体长相对增长率、体质量增长及蜕壳量均显著大于对照组( P <0.05),第2个月两组各数据无显著差异( P >0.05);隐蔽组亚成体螯虾摄食量、体质量及蜕壳量均小于对照组。研究结果表明,隐蔽所在螯虾的早期生长阶段对其生长有促进作用,但随着螯虾体格的增大,隐蔽所的促进作用随之减弱,甚至最终抑制螯虾的生长。本研究围绕克氏原螯虾穴居的习性以及趋触性等行为的特点,为生产提供了合理建议。

Effect of Shelters on Red Swamp Crayfish Procambarus clarkii at Different Growth Stages

Red swamp crayfish ( Procambarus clarkii ) with body weight of 0.527 g (juvenile) and 6.100 g (subadult) were reared in a circular plastic box with a bottom area of 113 cm 2 and 12 cm high at a stocking rate of 1 individual per box,where PVC tubes with a diameter of 1.9 cm were placed as a shelter in group A,and without PVC tubes as control group under the same conditions and management to investigate the effect of shelter on the growth of the crayfish with different sizes by measuring the growth in body length,body weight,survival rate and sheltering rate. The results showed that body length growth,relative growth rate in body length,weight growth and molting rate were significantly higher in group A than in the control group in the early stage (the first month) of juvenile crayfish ( P <0.05),while there was no significant difference between the two groups in the later stage (the second month)( P > 0.05 ). In the experiment of subadult crayfish,food intake,weight growth and molting rate were significantly lower in group A than in control group. Our findings indicated that shelters can promote growth of crayfish in their early stage. As crayfish grew and became big in size,however,the shelters showed less growth promotion,even inhibited the growth of crayfish. The instinctive behaviors of the crayfish including burrowing and thigmotaxis were discussed on the results of this experiment and previous studies,and a reasonable suggestion is provided for the production of crayfish combining the productive demand.