中文摘要：

研究光照对细鳞裂腹鱼胚胎孵化及20日龄内仔鱼生长、摄食的影响,探讨了细鳞裂腹鱼胚胎及仔鱼所需的适宜光照条件,为该鱼的基础生物学研究积累资料,也为人工繁殖和养殖生产提供参考。仔鱼为人工育苗池中随机抽取的初孵仔鱼,仔鱼饵料为小球藻和鲜酵母混合培育的褶皱臂尾轮虫。水源为天然河水,试验期间水温16.0-18.0℃、溶解氧6.8-8.5 mg/L、pH 6.5-6.8,采用三基色节能荧光灯为暗室内光源。结果表明,在10-360 lx范围内,随着光照强度的增加,孵化率逐渐升高,300-360 lx时达到最高的孵化率88.1%,此后孵化率随着光照强度的增大又有所下降,细鳞裂腹鱼受精卵孵化适宜的光照强度为300-720 lx。光照对细鳞裂腹鱼仔鱼的生长及摄食有显著影响。12日龄后的仔鱼在40-60 lx光照强度下生长最好、摄食强度最大,400-600 lx次之;此后随着光照强度的增大,摄食强度又显著下降。在40-6 000 lx范围内随光照强度的增强,摄食强度下降,生长则变差。黑暗条件下的仔鱼摄食强度和摄食率最低,生长接近停滞,在15日龄时全部死亡。细鳞裂腹鱼仔鱼在20日龄以内的适宜光照强度为40-600 lx。

英文摘要：

Schizothorax chongi,a cold water fish species naturally inhabiting the upper Yangtze and Jinsha River,Jialing River and Yalong River,has suffered quickly declining populations in recent years. Important factors in the decline include interruption of free flowing rivers and other changes in hydrological regime produced by damming.Secondary effects,such as light intensity and water depth in spawning grounds,also affect the survival of S. chongi. In this study,the effects of light intensity on the hatching rate of fertilized S. chongi eggs and on larval growth and feeding over the first 20 days were measured. Parental S. chongi were collected from the lower Yalong River and fertilized eggs were obtained by artificial insemination. The eggs were incubated under six illumination intensities（ 1 000-1 200,600-720,300-360,100-120,10-12,0 lx）. The number and date of newly hatched S.chongi larvae were recorded for each illumination treatment. Newly hatched S. chongi larvae were randomly assigned to one of five light intensity groups（ 4 000-6 000,1 400-1 800,400-600,40-60,0 lx）,with 200 larvae per group. Every 2-3 days,S. chongi larvae in each light treatment were randomly selected for determination of total length,feeding intensity and feeding rate. Experimental conditions were as follows： water temperature,16. 0-18. 0℃; DO,6. 8-8. 5mg/L and pH of 6. 5-6. 8. Illumination intensity had a significant effect on the hatching rate of S. chongi eggs（ F = 391. 51,P〈0. 01）. From 10 to 360 lx,hatching rate increased with intensity,reaching the maximum value（ 88. 1 %） in the 300-360 lx group. The hatching rate declined slowly at illumination intensities above 360 lx and the suitable light intensity for hatching S. chongi eggs is 300-720 lx. Light intensity also had a significant effect on the growth and feeding of S. chongi larvae during the first 20 days. After 9days,S. chongi larvae in the 40-60 lx treatment group displayed the fastest growth and highest feeding intensity,followed by the 400-600 lx group. Abo