河川沙塘鳢对猎物种类和大小选择性研究

PREY SPECIES AND SIZE SELECTION OF ODONTOBUTIS POTAMOPHILA

  • 摘要: 为了明确河川沙塘鳢(Odontobutis potamophila Günther)养殖宜投喂饵料生物的种类和规格, 通过室内外试验研究了沙塘鳢对生活习性不同8种饵料生物的种类选择, 对不同规格赤眼鳟(Squaliobarbus curriculus Richardson)的选择, 以及其不同生长阶段对饵料鱼大小的选择。研究结果表明, 沙塘鳢对麦鲮(Cirrhinus mrigala Hamilton)的选择指数显著大于其对剩余7种饵料生物的选择指数; 在无仿真水草条件下, 沙塘鳢对小规格饵料生物的选择指数显著大于对大、中规格饵料生物的选择指数; 在仿真水草条件下, 沙塘鳢对小规格饵料生物的选择指数显著大于其对大规格饵料生物的选择指数。在不同生长阶段中, 沙塘鳢全长与其捕食的饵料鱼全长呈现正相关关系; 沙塘鳢捕食的饵料鱼PPR值为0.23—0.73, 均值为0.49±0.1(均值±标准差); 随沙塘鳢规格的增加其捕食饵料鱼的PPR值降低, 捕食饵料鱼规格分布小于环境中饵料鱼规格分布。综上, 沙塘鳢养殖宜投喂饵料鱼麦鲮, 饵料鱼PPR值宜为0.38—0.6。

     

    Abstract: Odontobutis potamophila Günther is a carnivorous and high-priced fish species. Shrimp is the prey of O. potamophila which has high cost, so, prey fish with lower price may be more suitable for O. potamophila culture. In this study, we verified the prey selection of O. potamophila during different growth stages using eight prey species, and identifid prey species of a suitable size for O. potamophila culture in three different sizes. The results showed that O. potamophila had a strong selectivity for Cirrhinus mrigala Hamilton, with the preference index which was significantly higher than that of the seven other prey species. O. potamophila also exhibited strong selectivity for small-sized individuals, such as Squaliobarbus curriculus Richardson. Significantly positive linear relationship was observed between the total length of O. potamophila and C. mrigala. Prey-to-predator size ratio (PPR) for C. mrigala consumed by O. potamophila ranged from 0.23 to 0.73 (0.49±0.1: mean±SD). With the increase in O. potamophila sizes, PPR for C. mrigala consumed by O. potamophila decreased. Moreover, O. potamophila fed relatively smaller C. mrigala during different growth stages. Overall, the results indicated that C. mrigala with PPR of 0.38—0.6 could be used as a prey for O. potamophila culture.

     

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