长江和珠江水系1龄草鱼生长性能分析

Comparison of growth performance in stocks of 1 year old grass carp from Yangtze River and Pearl River

为评估长江水系和珠江水系草鱼Ctenopharyngodon idella群体的生长性能,在广东佛山对来自长江水系的监利、石首、宁乡草鱼群体和来自珠江水系的清远、佛山、肇庆草鱼群体的繁殖后代进行生长对比试验,从每个群体随机选择300尾样品,注射电子芯片标记后同塘养殖,并分别在4、8、12月龄时测量样品的体质量和体长性状。结果表明：4月龄时,6个群体间体质量和体长差异均不显著（P〉0.05）,8月龄时,群体间体质量和体长差异逐渐增加;12月龄时,佛山群体平均体质量最大（671.59 g）,比其他群体平均体质量大1.25%~16.79%,清远群体平均体质量最小（82.92 g）,监利群体平均体长最长（31.11cm）,比其他群体长4%~16%,清远群体平均体长最短（26.92 cm）,显著短于其他群体（P〈0.05）;12月龄时,珠江水系3个群体草鱼肥满度为2.55~3.30,长江水系草鱼肥满度为2.07~2.52,珠江水系草鱼群体的肥满度明显高于长江水系。本研究结果可为快速生长草鱼新品种基础种群的确定提供±据。

Three hundred individuals of grass carp Ctenopharyngodon idella were randomly sampled from six popu-lations including Yangtze River （Jianli population, Shishou population, and Ningxiang population） and Pearl River （Qingyuan population, Foshan population, and Zhaoqing population） and cultured in the same pond to assess growth performance in stocks of grass carp. Body weight and body length of grass carp were measured at 4 months old, 8 months old and 12 months old. The results showed that there was no significant difference in initial body weight and body length of the six population （P〉0.05）. However, the difference in body weight and body length was found to be gradually increased, with average body weight of 671. 59 g in Foshan population, 1.25%16.79% higher than that in other stocks, the minimum average body weight of 82.92 g in Qingyuan population in 12 months. The Jianli population had average body length of 31. 11 cm, 4 % 16% higher than that in other stocks. The minimal body length of 26. 92 cm was observed in Qingyuan population, significantly lower than that in other populations （P〈0. 05）. In 12 months, the Pearl River populations had condition factor of 2. 55-3. 30, and Yangtze River populations condition factor of 2. 07-2. 52, higher in Yangtze River populations than in the Pearl River ones. The findings will lay foundation for searching for good growth grass carp populations.