GROWTH PERFORMANCE AND GENETIC ANALYSIS OF DIFFERENT POPULATIONS OF BIGHEAD

From 1982 to 1986, the growth rates of two- and three-year-old bighead(Aristichthys nobilis)from different populations were compared in intensive grow-up ponds in Shanghai and Guangdong, using a random block design. The bighead populations studied were: the wild population from the Changjiang River, the hatchery population from the Changjiang River basin, the wild population from the Zhujiang River, and the hatchery population from the Zhujiang River basin. The results indicated that, cultured in the same environment, fish from the wild populations grew faster than those from the hatchery populations; fish from the wild population from the Changjiang River grew faster than those from the wild population from the Zhujiang River; fish from the hatchery population from the Changjiang River basin grew faster than those from the hatchery population from the Zhujiang River basin; the differences in growth rate were about 5%. Analyses of variance and genetic correlation further revealed that the genetic factor played an important role in causing the differences in growth rate among the different populations.