中文摘要：

为了探讨胭脂鱼个体发育过程中集群行为的发生机理，在20℃水温下，在胭脂鱼孵化后第5天开始至第39天，记录体长，采用视频分析的方法连续观察其游泳行为，计算胭脂鱼的游泳速度（V），相对全长最近邻距离（DNNL），分离游泳指数（ISS），根据胭脂鱼的游泳速度计算基于全长雷诺系数（RL）。结果显示，随着日龄的增加，胭脂鱼仔鱼全长呈Y=1．26033—0．01558x＋0．00315x2-（4．84978E-5）X3增加，游泳速度先增加后降低并趋于稳定，在19日龄后相对全长游泳速度稳定于（2．45＋0．15）TL／s。胭脂鱼仔鱼ISS随着时间显著降低，至第19天时显著低于随机分布预期值，至32天时稳定于最低值；DNNL的变化趋势与ISS相符；表明胭脂鱼仔鱼集群行为于19日龄（1．77cm全长）开始，至32日龄（2．40cm全长）时形成紧凑的集群行为。RL随日龄的增加呈Y=-607．89161＋156．80912x-4．2129x。＋0．0379x。方程增加，在仔鱼开口期（5—6日龄）即大于200，在19日龄时值为1111。结果表明，仅从RL的角度不能解释胭脂鱼集群行为的发生，胭脂鱼的集群行为可能更多的与生物学因素如游泳行为有关，其游泳模式随着集群行为的发生由间歇高速游泳向持续巡游游泳转变。

英文摘要：

Juveniles Chinese sucker （Myxocryprinus asiaticus ）obtains schooling swimming behavior. However, it is unclear when and why they form schooling behavior. We researched the mechanism of schooling formation related to hydraulics. We analyzed swimming behavior of Chinese sucker that ranged from 5 to 39 days post hatching（dph）at 20℃ water temperature by video record. Swimming speed,nearest neighbor distance（DNN）, separation swimming index（ISS）and the Reynolds number based on total length （RL） were calculated. ISS decreased significantly with age, significantly lower than random distribution value at 19 dph（ 1.77 cm in total length,TL）and became stable at the lowest value at 32 dph（2.40 cm,TL）. DNN changed in a similar way to ISS. The variation of ISS and DNN illustrated the schooling behavior was formed at the 19 dph and became tight schooling at 32 dph. The total length increased with age at function y = 1. 260 33 -0. 015 58×x ＋0. 003 15 × x2 - （4. 849 78E - 5） × x3. Swimming speed first increased and then decreased and finally became stable at 2.45 ＋ 0. 15 TL/S after 19 dph. RL increased with age at function y = -607. 891 61 ＋ 156. 809 12 ×x -4. 212 9 ×x2 ＋0. 037 9 ×x3,RL exceeded 200 at 5 -6 dph, equaled 1 111 at 19 dph. Analyses showed that the RL did not explain the schooling behavior of Chinese sucker, and schooling behavior was more likely related to the swimming behavior, as swimming changed from intermittent sprinting to continuous cruising when schooling was formed.