盐度对斑节对虾蜕壳、存活、生长和饲料转化率的影响

对平均体重1.20±0.05g的斑节对虾（Penaeus monodon）稚虾进行为期30d的养殖试验,分别测定其在不同养殖盐度条件下的蜕壳间期、成活率、特定增长率和饲料转化率。斑节对虾的成活率在盐度5时最低,低于60%,与其它盐度试验组差异显著,而其它试验组之间差异不显著。在5～25盐度范围内,蜕壳间期随着盐度升高而延长,盐度达30以上后又缩短,25时为最大值;盐度5、10和15之间差异显著,15、20、30和35之间差异不显著。特定增长率和饲料转换率随盐度升高呈现双峰的波浪式变化趋势;特定增长率在盐度20（3.18±0.14）%·d^-1和25（2.98±0.26）%·d^-1时达到最高。蜕壳间期与生长率存在极显著的正相关关系（P〈0.001）。在盐度20、25、30时饲料转化率高,分别为（52.76±3.06）%、（54.90±5.14）%和（51.56±7.58）%,与其它盐度试验组之间差异显著。因此,斑节对虾养殖的适宜盐度应为20～30,在此条件下可实现较高的成活率、特定增长率和饲料转换率。

Effect of salinity on molting, survival, growth and feed conversion rate of juvenile Penaeus monodon

Juveniles Penaeus mondon with average weight（1.20±0.05 g） were cultured at salinities of 5,10,15,20,25,30 and 35.The intermolt period,survival rate,specific growth rate（SGR） and feed conversion rate（FCR） were analyzed.The results showed that survival rate of P.monodon at salinity 5 was the lowest（〈60%） and significantly different（P〈0.05） from that of the other salinity groups,and there were no significant（P〉0.05） differences in survival rate among the other salinity groups.With the salinity increasing from 5 to 25,the intermolt period increased,and when the salinity was over 30,the intermolt period decreased,the peak was appeared at salinity 25;there were significant differences among salinity 5,10,15 groups,but no significant differences among salinity 20,25,30,35 groups.As the salinity increasing,the SGR and FCR showed a wavy line with double peaks.SGR was higher at salinity 20（3.18±0.14）%·d^-1 and 25（2.98±0.26）%·d^-1.There was a significant positive relationship between the intermolt period and SGR（P〈0.001）.FCR was higher at salinity 20～30 and significantly different from that of the other treatments.The results suggusted that the optimal salinity for P.monodon culture was 20～30 at which higher survival rate,SGR and FCR can be attained.