Aquaculture and Fisheries Group, Wageningen University, P.O. Box 338, 6700 AH Wageningen, The Netherlands.
J Fish Biol. 2010 Jun;76(10):2486-501. doi: 10.1111/j.1095-8649.2010.02635.x.
The objective of this study was to assess whether and how coping strategies affect the welfare of African catfish Clarias gariepinus housed at low and high densities. Group composition influenced feed intake; re-active groups (comprised of 100% re-active fish) had a lower specific growth rate (G) and feed intake and a higher feed conversion ratio (R(FC)) than pro-active groups. Furthermore, re-active groups had a lower energy retention than pro-active groups. The latter was fully due to differences in feed intake, since energy partitioning (on % total gross energy intake basis) was similar among the group composition treatments. Fish held at high stocking density showed a higher R(FC) and feeding speed and a lower energy retention and agonistic behaviour. None of the measured variables was influenced by the interaction effect. In mixed groups, G and number of skin lesions seemed to be affected by different behavioural phenotypes at low stocking density, but not at high density. These results indicate that both stocking density and group composition affect physical and behavioural responses of C. gariepinus. Furthermore, physical and behavioural data of individual fish housed in mixed groups suggest that coping strategy affects the fitness of different behavioural phenotypes at low, but not at high, stocking density.
本研究旨在评估应对策略是否以及如何影响低密度和高密度养殖的非洲鲶（Clarias gariepinus）的福利。群体组成影响饲料摄入量；反应型组（由 100%反应型鱼组成）的特定生长率（G）、饲料摄入量和饲料转化率（R(FC)）均低于积极型组。此外，反应型组的能量保留率低于积极型组。后者完全是由于饲料摄入量的差异所致，因为在不同的群体组成处理中，能量分配（基于总摄入总能量的百分比）相似。高密度养殖的鱼类表现出更高的 R(FC)和摄食速度，以及更低的能量保留率和攻击行为。没有一个测量变量受到相互作用的影响。在混合群体中，在低密度下，G 和皮肤损伤数量似乎受到不同行为表型的影响，但在高密度下则不受影响。这些结果表明，养殖密度和群体组成都会影响非洲鲶的生理和行为反应。此外，在混合群体中饲养的个体的生理和行为数据表明，在低密度下，应对策略会影响不同行为表型的适应性，但在高密度下则不会。
