钱塘江桐庐段水域花渔业种群结构特征的初步研究

利用2012年2月至2013年1月在钱塘江桐庐段水域的渔获物中采集的样本,对该水域花（Hemibarbus maculatus Bleeker）种群的叉长和体质量组成,性别组成和性比、年龄组成等渔业种群结构特征进行了初步研究。结果表明,渔获群体的叉长范围为11.2~33.1 cm,平均叉长为（20.2±3.45）cm;体质量范围为26.0~540.8 g,平均体质量为（171.6±81.9）g。雌性个体大于雄性个体,雌性渔获群体的平均叉长为（23.5±3.58）cm,平均体质量为（183.2±79.87）g;雄性渔获群体的平均叉长为（22.7±3.77）cm,平均体质量为（168.8±78.99）g。雌性群体数量多于雄性群体数量,雌、雄性比约为1.47∶1。渔获群体由4个年龄组组成,以2龄为主。

Primarily study on fish community structure of Hemibarbus maculatus in Tonglu area of the Qiantang River

Hemibarbus maculatus,as a kind of important economic freshwater fish,is widely distributed all over the river systems except for Xinjiang,Tibet. Characteristics of fish stock structure of Hemibarbus maculatus such as fork length composition,body weight composition,sex ratio of population,age construction,and so on,were primarily studied according to the data collected from commercial catch in Tonglu water of Qiantang River from February 2012 to January 2013. The result showed that the fork length construction of H. maculatus was from 11. 2 cm to 33. 1 cm with the average of（ 20. 2 ± 3. 45） cm. The body weight construction of H. maculatus was from 26. 0 g to 540. 8 g with the average of（ 183. 2 ± 79. 87） g. The female of H. maculatus was bigger than the male in size. The fork length average and the body weight average of the female of H. maculatus was（ 23. 5 ± 3. 58） cm and（ 183. 2 ± 79. 87） g,respectively,while（ 22. 7 ± 3. 77） cm and（ 168. 8 ± 78. 99） g,respectively,of the male. There is an imbalance in the population amount between the female and male. The sex ratio of population is 1. 47 ∶ 1. The population of H. maculatus is composed of four age groups and most of them are belonged to two age old.