投喂水平对长吻 仔稚鱼生长和存活的影响

Effects of feeding level on growth performance of Chinese longsnout catfish (Leiocassis longirostris Gnther) larvae

  • 摘要: 以长吻(鱼危)仔鱼为实验对象, 探讨不同投喂水平对7-14日龄阶段和21-29日龄阶段的长吻(鱼危)仔稚鱼存活、生长以及鱼体组成的影响。7-14日龄阶段设计6个投喂水平, 分别为: 20、30、40、50、60和70 % IBW/d(IBW: initial body weight); 21-29日龄阶段设计6个投喂水平: 10、20、30、40、50、60 % IBW/d。实验结果表明: (1)投喂水平显著影响长吻(鱼危)仔稚鱼的存活和生长(P0.05)。7-14日龄阶段, 投喂水平为30%-60% IBW/d处理组的仔鱼存活率显著高于20%与70 % IBW/d投喂组(P0.05)。特定生长率随投喂水平的增加显著上升, 以60% IBW/d投喂组最高(P0.05)。21-29日龄期间, 10% IBW/d投喂组存活率显著低于50% IBW/d投喂组(P0.05), 特定生长率(SGR)则显著低于其他各处理组(P0.05); (2)鱼体体长体重变异系数未受投喂水平的显著影响。鱼体产出与饲料投入之比、鱼体水分含量随投喂水平升高显著下降(P0.05), 粗蛋白含量则显著上升(P0.05); 粗脂肪和粗灰分含量无显著差异; (3)分别通过存活率和投喂水平做一元二次回归、特定生长率与投喂水平做折线回归得到7-14日龄阶段的仔鱼最适投喂水平为43 % IBW/d; 通过仔鱼存活率和特定生长率与饲料投喂水平做折线回归得到21-29日龄阶段的仔鱼最适投喂水平分别为30.62% IBW/d和28.41% IBW/d。

     

    Abstract: Chinese longsnout catfish, Leiocassis longirostris Gnther is a high value aquaculture species in China. This study was carried out to investigate the optimal feeding level on the growth, survival, body composition, coefficient of variation of body wet weight and body length for Chinese longsnout catfish larvae of 7-14 dph and 21-29 dph, and for a need to determine the optimal feeding level in the commercial larviculture operations. Six feeding levels of 20, 30, 40, 50, 60 and 70% initial body weight (IBW)/d for 7-14 dph larvae, and 10, 20, 30, 40, 50 and 60% IBW/d for 21-29 dph larvae were adopted, respectively. The results showed that growth performance and survival rate was significantly higher in 7-14 dph larvae fed at the feeding levels of 30%-60% IBW/d than 20% and 70% IBW/d (P0.05). Specific growth rate (SGR) increased with the increasing feeding levels and reached the highest level at the 60% IBW/d group (P0.05). For 21-29 dph larvae, the survival rate and SGR were significantly lower in the 10% IBW/d group than in the 50% IBW/d group (P0.05). In both trials, differentiations of body wet weight and body length in larvae were not affected by the feeding level (P0.05). Body crude fat and ash content were also not affected by the different feeding level. Ratio of weight gain to feed consumption and body moisture contents in larvae significantly decreased while body protein contents increased with the increasing feeding levels (P0.05). Based on quadratic linear regression analysis of survival rate and broken line analysis of SGR in relation to the feeding level, the optimal feeding level for 7-14 dph larvae was 43% IBW/d. Based on the broken line analysis between the survival rate or specific growth rate and the feeding level, the optimal feeding levels for 21-29 dph larvae were 30.62% IBW/d and 28.41% IBW/d, respectively.

     

/

返回文章
返回