LIU Si-lei1，WANG Yin-ping2，LI Pei-jie2，CAO Guo1，WANG Lei1，DAI Pei2，LIU Kai1,2*
1.National Demonstration Center for Experimental Fisheries science Education, Shanghai Ocean University, Shanghai 201306, China；2.Scientific Observing and Experimental Station of Fishery Resources in the Lower Reaches of Changjiang River, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
Abstract: Growth and mortality parameters were estimated by ELEFAN I technique, and the population dynamics trend was evaluated by the Beverton-Holt dynamic model in 1271 samples of freshwater bream Parabramispekinensis collected in the lower reaches of the Yangtze River from May 2017 to April 2018 monthly by a 2 cm mesh trap with 25 m in width and 6 m height to explore the population structure, growth and mortality characteristics and resource utilization status in Zhenjiang section of the Yangtze River. The maximal freshwater bream in number was sampled in the lower reaches of the Yangtze River in June (180 individuals) and July (174 individuals) and in volume in February (14.66 kg) and May (14.31 kg). The quantity of freshwater bream were accounted for 18.53% of the total catches sampled by nets, just less than Hemiculterbleekeri and Pseudobramasimoni, and the sampling weight were 12.86% of the total catches sampled by nets, lower than those of silver carp Hypophthalmichthysmolitrix, bighead carp Aristichthysnobilis and grass carp Ctenopharyngodonidellus. The freshwater bream had body length ranging from 51.98 mm to 330.00 mm, with the mean value of (161.03±40.50)mm and body weight of 2.15-584.00 g, with the mean value of (85.02±70.25)g, with power function relationship between body length and body weight was W=1.0×10-5L3.0309 (R 2= 0.953, n=1271). Growth of freshwater bream was described using a Von Bertalanffy model, with L∞=391.35 mm， W∞=720.79 g, k =0.51, and t0 =-0.32 a. The turning point for body weight growth curve of the stock was situated at t =1.85 year old, annual natural mortality coefficient M was then estimated using Pauly’s empirical equation as 0.88, and length-converted catch curves were used to estimate the annual total mortality coefficient Z,which was found to be 2.52. Accordingly the fishing mortality coefficient (F) was equal to 1.64, and the annual current exploitation rate was 0.65, showing the stock was over-exploited. The Beverton-Holt dynamic model revealed that the minimum capture size for freshwater bream was 234.81 mm (1.49 years old), the fishing season was further extended to the end of August to strengthen the effective protection of the recruitment groups in the Zhenjiang section as well as other economically important fishes, and promote resource conservation and sustainable utilization.
刘思磊, 王银平, 李佩杰, 曹过, 汪雷, 代培, 刘凯. 长江镇江段鳊生长特征及种群参数估算[J]. 大连海洋大学学报, 2019, 34(5): 725-732.
LIU Si-lei, WANG Yin-ping, LI Pei-jie, CAO Guo, WANG Lei, DAI Pei, LIU Kai.
2019, Vol. 34 
