中文摘要：

以南方鲇（Silurus meridionalis）、瓦氏黄颡鱼（Pseudobagrus vachelli）、青鱼（Mylopharyngodon piceus）、锦鲫（Caras-sius aumtus）等4种幼鱼为研究对象,在25℃条件下分别测定它们的临界游泳速度（Ucrit）和1.5倍Ucrit条件下的耐受时间。通过比较两种方式的游泳能力发现,4种幼鱼的Ucrit存在显著差异（p〈0.05）,其中南方鲇的Ucrit最低,而锦鲫的Ucrit最高,青鱼和瓦氏黄颡鱼的Ucrit则介于两者之间;南方鲇和瓦氏黄颡鱼之间的的耐受时间差异不显著,二者却显著高于青鱼和锦鲫,而锦鲫的耐受时间在4种幼鱼中最短（p〈0.05）。上述结果表明,南方鲇和瓦氏黄颡鱼在较高速度下的运动耐受能力更强,而临界游泳能力相对较低;锦鲫和青鱼则与此相反;它们的两种运动能力之间均存在着权衡,这种权衡可能与鱼类的生态习性之间存在着某种关联。

英文摘要：

The critical swimming speed （ Ucrit ; n = 8 ） and endurance time （ n = 8 ） at 1.5 Ucrit were measured respectively in juvenile southern catfish （ Silurus meridionalis）, black carp （ Mylopharyngodon pieeus）, darkbarbel catfish （ Pseudobagrus vachelli） and crnelan carp （ Carassius aumtus） at 25 ℃. Comparing with two kinds of swimming performance it was discovered that critical swimming speed of four species of juvenile fish showed significant differences（p 〈 0.05 ）, in which southern catfish had the slowest critical swimming speed and crucian carp had the highest, critical swimming speed of darkbarbel catfish and black carp were intervenient. Endurance time of southern catfish and darkbarbcl catfish showed no significant differences, but were higher than black carp and crucian carp significantly, whereas endurance time of crucian carp was shortest and lower than other three species significantly （p 〈 0.05 ）. These results above-mentioned suggest that endurance swimming performance of southern catfish and darkbarbel catfish at high speed are stronger, but critical swimming performance are relative lower; Crucian carp and black carp are just reversed; although four species of juvenile fishes are good at different kinds of swimming ability respectively, a trade-off between two kinds of swimming performance exists in all fishes used in this study ; The trade-off maybe related to characteristic ecological habits of fishes.