不同盐度对龙虎斑生长和摄食的影响

Effect of Different Salinity on Growth and Feeding of Hybrid Grouper(Epinephelus lanceolatus ♂×E.fuscoguttatus♀)

在盐度5、10、15、20、25、30条件下,以全人工配合饵料饲喂龙虎斑[鞍带石斑鱼（Epinephelus lanceolatus♂）×棕点石斑鱼（E.fuscoguttatus♀）]60 d,研究不同盐度对龙虎斑生长和摄食的影响。结果表明,不同盐度对龙虎斑生长的影响有统计学意义（P〈0.05）,盐度5-20组增长率、特定生长率均高于盐度25、30组,差异有统计学意义（P〈0.05）,盐度10组的增长率最高,为55.08%,盐度15组的特定生长率最大,为2.30%/d,盐度和龙虎斑生长速率的回归方程为K=0.000 09 S 4-0.006 S 3＋0.131 S 2-1.055 S＋4.832（R 2=0.984）;不同盐度对龙虎斑的摄食率和饵料系数影响有统计学意义（P〈0.05）,盐度15组的摄食率最高,为1.64%/d,其次为盐度10组,为1.60%/d,饵料系数在盐度15组最低,为0.820,其次为盐度10组,为0.827。因此,龙虎斑在低盐度条件下生长比高盐度快,摄食率高,饵料利用率高,最佳生长盐度为10-15。

Effect of different salinity （5, 10, 15, 20, 25 and 30, respectively） on growth and feeding of dragon-tiger grouper （Epinephelus lanceolatus ♂x E. fuscoguttatus ♀） fed with artificial bait was studied. The results indicated that there was significant difference in the growth of dragon-tiger grouper at different salinity （P 〈 0.05）. The length gain rate and specific growth rate were higher at the salinity of 5 - 20, with the statistical difference from those at salinity 25 - 30 at the level ofP 〈 0.05, and the length gain rate reached the maximum 55.08% at salinity 10, and the specific growth rate was the highest （2.30%/d） at salinity 15. The regression equation of salinity and the growth speed of dragon-tiger grouper was K = 0.000 09 S4 - 0.006 S3 ＋ 0.131 S2 - 1.055 S ＋ 4.832 （R2 = 0.984）. There was also statistical difference in the feeding rate and feed coefficient of dragon-tiger grouper at different salinity （P 〈 0.05）. The feeding rate, which was 1.64%/d, was the highest at the salinity of 15. At the salinity of 10, the feeding rate was 1.60%/d. The feed coefficient, which was 0.820, was the lowest at the salinity of 15. At the salinity of 10, it was 0.827. Therefore, the dragon-tiger grouper grow faster in lower salinity than in higher salinity. Also, the feeding rate and feed efficiency are higher in lower salinity, and the most suitable salinity for the growth of the dragon-tiger grouper is 10 - 15.