初始放养密度对鳡幼鱼驯食及生长的影响

Effects of initial stocking density on weaning and growth of juvenile yellowcheek carp (Elopichthys bambusa R.)

试验设5组，于1．0m×1．0m×1．0m网箱中进行，初始放养密度为100尾／m3（D1组）、300尾／m3（D2组）、500尾／m3（D3组）、700尾／m3（D4组）、900尾／m3（D5组），试验期共28d，研究初始放养密度对鲢幼鱼驯食效果的影响。结果显示：累积死亡率（MR）和体质量变异系数（CV）随初始放养密度的增大先降低后升高，其中D3、D4组CV显著低于其他3组；总残食率（CR）随着初始放养密度的增大而升高；驯食成功率（WSR）随着初始放养密度的增大先升高后降低，其二次回归方程为Y=-1．101X2＋13．590X＋44．093，相关系数R2=0．931，最适初始放养密度为617尾／m3；特定生长率（SGR）随初始放养密度的增大而减小。在本试验条件下，综合考虑驯食成功率、驯食效率和操作强度，鲸的适宜初始放养密度为500--700尾／m3。

The present study aimed to investigate the effect of initial stocking density on the wea- ning and growth of juvenile yellowcheek carp （Elopichthys barnbusa R. ）. Five groups were assigned in triplicate in the net cages （1.0 m× 1.0 m× 1.0 m） with different initial stocking densities of 100 ind/m3 （D1）, 300 ind/m3 （D2）, 500 ind/m3 （D3）, 700 ind/m3 （D4） and 900 ind/m3 （D5）. The experiment was carried out for 28 days. The results showed that MR,CV decreased and then increased with the increasing of initial stocking density. CV in D1, D2, D5 was significantly higher than that in D3, D4. CR increased with the increasing of initial rearing density. WSR with the increasing of initial rearing density firstly increased and then decreased. Relationship between WSR and stocking density based on quadratic regression analysis was.Y= -1. 101X2 %13. 590X＋44. 093, correlation coefficient R2 =0. 931, the optimum initial stocking density was 617 ind/m3. SGR decreased with the increasing initial stocking density. It was concluded that the optimal initial stocking density of net cage for the weaning of juvenile yel- lowcheek carp was 500-700 ind/m3 based on WSR,weaning efficiency and manipulation strength.