POPULATION GROWTH CHARACTERISTICS AND STOCK ASSESSMENT OF PARACANTHOBRAMA GUICHENOTI (BLEEKER, 1864) IN KUILEI LAKE, JIANGSU PROVINCE, CHINA

From April 2013 to December 2014, the Paracanthobrama guichenoti were sampled and the population characteristics and stock assessment of Paracanthobrama guichenoti were carried out in Kuilei Lake in Jiangsu Province. The results indicated that the population of Paracanthobrama guichenoti was consisted of 6 age classes, of which the dominant age class was 1—2 years old, accounting for 72.18% of the total individuals. The second age class was 3—4 years old (22.59%), and the 5—6 years old age class accounted for only 4.62%. The relationship between the total length (L) and the body weight (W) can be expressed by the power function equation W=0.0037L^3.3137. The von-Bertalanffy of Paracanthobrama guichenoti can be predicated by the following equations: L_t=41.161–e^{–0.308(t+0.4953)}; W_t=828.111–e^{–0.308(t+0.4953)3.3137}. The growth parameter of L_∞ and W_∞ were 41.16 cm and 828.11 g, respectively. The growth inflexion point was t_i=3.39, and the corresponding total length and the body weight were 28.7 cm and 251.34 g, respectively. Our study suggests that the harvesting age should be over 3.39 years old in order to realize rational and sustainable utilization of the population resource in Kuilei Lake. The total mortality, the natural mortality, the fishing mortality, and the exploitation rate were 1.21/a, 0.63/a, 0.58/a and 0.48, respectively, and the total original resources of Paracanthobrama guichenoti were 9560 kg. Our study indicates that the exploitation of the population was in a reasonable state.