To investigate the swimming ability of two Schizothorax species in the Yalung River and provide basic parameters for the studies on fish behavior and the design of fish passage, we exa-mined the induced velocity, critical swimming speed, and burst swimming speed in Schizothorax dolichonema and Schizothorax prenanti with incremental velocity method and the durable swimming speed in S. dolichonema with fixed velocity method. The results showed that the induced velocity of both species increased first and then plateaued with the increases of body length, with the maximum values being lower than 0.2 m·s-1. The critical swimming speed and burst swimming speed of S. dolichonema were (0.81±0.20) and (1.49±0.26) m·s-1, respectively, while the relative critical swimming speed and the relative burst swimming speed were (4.90±1.73) and (9.77±1.72) BL·s-1 (BL: body length), respectively. For S. prenanti, the critical swimming speed and burst swimming speed were (0.73±0.24) and (1.17±0.39) m·s-1, respectively, while the relative critical swimming speed was (6.88±2.82) BL·s-1, and the relative burst swimming speed was (11.75±2.77) BL·s-1. The swimming duration of S. dolichonema was negatively correlated with the flow velocity of 0.7-1.5 m·s-1, and the relationship between fatigue time (T) and flow velocity (V) was fitted into lgT=-2.52V+5.59. The relationship between expected fishway length (d) and the tolerable maximum average flow velocity (Vf max) was accordingly derived to be Vf max=-0.17lnd+1.74. Taken together, the fishway targeting S. dolichonema and S. prenanti was recommended to generate the in-channel velocity larger than 0.2 m·s-1, while the velocity at the entrance and verticle slot should be 0.73-1.67 m·s-1, and the main-flow velocity in rest pools should be 0.2-0.7 m·s-1.
为探究雅砻江两种裂腹鱼的游泳能力,给过鱼设施设计和鱼类游泳行为学研究提供基础参数,本研究采用递增流速法对长丝裂腹鱼、齐口裂腹鱼的感应流速、临界游泳速度、突进游泳速度进行测试,采用固定流速法对长丝裂腹鱼的耐久游泳速度进行测试。结果表明: 长丝裂腹鱼与齐口裂腹鱼的感应流速随着体长的增加均出现了先增加后平稳的趋势,但最大感应流速均小于0.2 m·s-1;长丝裂腹鱼的临界游泳速度与突进游泳速度分别为(0.81±0.20)和(1.49±0.26) m·s-1,相对临界游泳速度为(4.90±1.73) BL·s-1,相对突进游泳速度为(9.77±1.72) BL·s-1(BL为体长);齐口裂腹鱼的临界游泳速度与突进游泳速度分别为(0.73±0.24)和(1.17±0.39) m·s-1,相对临界游泳速度为(6.88±2.82) BL·s-1,相对突进游泳速度为(11.75±2.77) BL·s-1。耐久测试发现,随着流速增加(0.7～1.5) m·s-1,长丝裂腹鱼持续游泳时间与水流速度呈负相关,疲劳时间(T)与水流速度(V)的关系可以拟合为lgT=-2.52V+5.59,预测鱼道长度(d)与鱼道内可通过的最大平均水流速度(Vfmax)的关系式为Vf max=-0.17lnd+1.74。根据试验结果,当以长丝裂腹鱼和齐口裂腹鱼为主要过鱼对象时,建议鱼道内最小水流速度应大于0.2 m·s-1,进口及竖缝处水流速度为0.73～1.67 m·s-1,休息池主流水流速度为0.2～0.7 m·s-1。.
Keywords: Schizothorax dolichonema; Schizothorax prenanti; fishway design; swimming ability.