养殖密度对克氏原螯虾生长及消化酶、免疫酶活性的影响

水温(25±1) ℃时,将体质量(3.11±0.10) g的克氏原螯虾幼虾饲养在120 cm×60 cm×20 cm的水族箱中,密度分别为14尾/m^( 2) (低密度组)、28尾/m^( 2) (中密度组)和42尾/m^( 2) (高密度组),研究室内养殖不同密度对生长、摄食、消化酶活性及非特异性免疫的影响。8周的养殖结果显示,克氏原螯虾的存活率随养殖密度的增大而降低。在28尾/m^( 2) 组中,其特定生长率(1.82±0.12)%/d]和质量增加率(196.73±0.76)%]显著高于其他两组( P< 0.05)。摄食率与养殖密度成正相关,即42尾/m^( 2) 组的摄食率高于14尾/m^( 2) 组和28尾/m^( 2) 组。28尾/m^( 2) 组消化酶活性显著高于14尾/m^( 2) 组的消化酶活性( P< 0.05),但与42尾/m^( 2) 组差异不显著( P >0.05)。不同养殖密度对非特异性免疫有显著影响,28尾/m^( 2) 组显著优于其他两组( P< 0.05)。综合所有指标,在本试验条件下,28尾/m^( 2) 的养殖密度最适合克氏原螯虾幼虾的养殖。

Effects of Stocking Density on Growth,Digestive Enzyme and ImmuneEnzyme Activities of Red Swamp Crayfish Procambarus clarkii

Juvenile red swamp crayfish Procambarus clarkii with body weight of (3.11±0.10) g was reared in a 120 cm×60 cm×20 cm aquarium at stocking density of 14 individuals/m 2 (group L), 28 individuals/m 2 (group M), and 42 individuals/m 2 (group H) at water temperature of (25±1) ℃ for 8 weeks in order to investigate the effects of different stocking densities on the growth, feeding, digestive enzyme activity and non-specific immunity of juvenile red swamp crayfish. The survival rate of the crayfish was found to be decreased with the increase in stocking density. There were significantly higher specific growth rate (1.82±0.12)%/d and body weight gain rate (196.73±0.76)% in group M than those in the other two groups ( P <0.05). The positive correlation between feeding rate and stocking density was observed in each group, higher feeding intake rate in group H than that in group L and group M. There were significantly higher activities of digestive enzymes in group M than those in group L ( P <0.05), without significantly different from those in group H ( P >0.05). The non-specific immunity of the crayfish was significantly affected by stoking density ( P <0.05), significantly better in group M than that in the other two groups. The findings indicate that the optimal stocking density is 28 individuals/m 2 in juvenile red swamp crayfish culture under the experimental conditions.