The Population Structure and Growth Characteristics of Hucho taimen(Pallas)in the upper Reaches of Wusuli River

Jiang Zuofa, Tang Fujang, Yin Jiasheng, Dong Chongzhi(Heilongjiang River Fishery Research Institute of Chinese Academy of Fishery Sciences, Harbin 150070, P. R. China)

Upper reaches of Wusuli River; Hucho taimen(Pallas); Population structure; Growth characteristics

The growth characteristics and population structure of Hucho taimen (Pallas) in the upper reaches of Wusuli River were investigated in 2002～2003. The structures of body length, body weight, age and the growth characteristics of the population were analyzed based on analyzing 339 samples. The results show that the population structure is reasonable, and young and breeding individuals take main part in the population, which is important to restore resources. By means of biostatistics analysis, the relationship between body length, L(cm) and body weight, W(g), may be stated by W=0.011 5 L 3.022 3(r=0.995 8). The Von Bertalanffy equations can be calculated as L t=186.00[1-e -0.069 9(t-0.785 0 )], W t=1 2651.26[1-e -0.069 9(t-0.785 0)] 3.022 3, with an inflexion being at t=16.5,correspondingly W=3 714.71 g. Female fishes matures at the age of about 6+ and the male ones 5+, and sex ratio(♀:♂)is about 1.13:1. The growth parameters reflects that Hucho grows fast before the age of 8+ and then slow down, that means Hucho taimen (Pallas) in the upper reaches of Wusuli River grows more actively before 8+ years old, however, elder ones still grows fast relatively.