珠江中下游草鱼渔业生物学特征研究

Biological characteristics of Ctenopharyngodon idellus in middle and lower reaches of Pearl River

  • 摘要: 根据2019—2020年珠江中下游草鱼 (Ctenopharyngodon idellus) 种群调查数据,对其群体结构和生长现状进行了分析。结果显示,草鱼种群个体体长介于103~665 mm,平均体长为 (347.89±96.73) mm;体质量介于21.4~6 650.0 g,平均体质量为 (986.87±842.96) g。草鱼种群年龄结构为0+~5+龄,优势年龄组为1+、2+和3+龄,占样本总数的92.8%。草鱼体长 (L) 和体质量 (W) 呈显著幂函数关系,为匀速生长类型。Von Bertalanffy生长方程参数:L=1187 mm,k=0.128,t0=−0.282,W=31 344.51 g,生长特征指数φ=5.26,生长拐点年龄为8.29。总死亡系数Z=0.58,自然死亡系数M=0.29,捕捞死亡系数F=0.29,开发率E=0.5。草鱼雌雄个体数的比例为1.07∶1,性腺成熟度以Ⅱ期为主,相对繁殖力为46.28 粒·g−1。与历史资料相比发现,草鱼生长性能下降,种群呈现小型化,繁殖力下降,为促进珠江中下游草鱼资源的恢复,建议降低捕捞强度,开捕体长应大于791 mm,体质量应大于9 279.11 g。

     

    Abstract: In order to find out the current status of the population structure and growth characteristics of grass carp (Ctenopharyngodon idellus) in the middle and lower reaches of the Pearl River, we have investigated the grass carp population from 2019 to 2020. The results show that the body length of grass carp was 103−665 mm average: (347.89±96.73) mm. The body mass was 21.4−6 650.0 g average: (986.87±842.96) g. The population age was of 0+−5+, and the dominant age was 1+−3+, accounting for 92.8% of the total number of samples. The body length had a significant power function relation with body mass for uniform motion pattern. The growth could be described by Von Bertalanffy equation with the growth parameters: L=1187 mm, k=0.128, t0=−0.282, W=31 344.51 g. The index of length growth performance (φ) of grass carp was 5.26, and the growth inflection age was 8.29. The total mortality rate, natural mortality rate, fishing mortality rate and exploitation rate were 0.58, 0.29, 0.29 and 0.5, respectively. The sex ratio (Females/Males) was 1.07: 1. The sexual maturation was mainly at Stage II. Compared with the previous data, the growth performance and fecundity of grass carp all showed a decline tendency; the population structure tended to be miniaturized. In order to promote the recovery of grass carp resources in the middle and lower reaches of the Pearl River, it is recommended to reduce the fishing intensity. Besides, the catch body length should be greater than 791 mm and the mass should be greater than 9 279.11 g.

     

/

返回文章
返回