环境因子对双清溪浙江华溪蟹(Sinopotamon chekiangense Tai et Song)种群变动的影响

The effects of environmental factors on the fluctuations of Sinopotamon chekiangense Tai et Song's population

2003～2004年对天目山双清溪主要水体设立16个测站进行水质测定和浙江华溪蟹的种群变动调查,结果表明种群数量出现显著下降趋势.溪蟹种群的个体数量特征是以小型个体为主,随着生长大型个体数量急剧减少;在种群生物量变化中起主导作用的是大型个体的数量和规格;种群性别比例维持在3.51～3.91.重金属Zn2+、Gr6+、Gu2+在双清溪中出现并有一定的含量(分别为0.06ppm、23ppb、0.02ppm),这是造成种群生物量和个体规格下降的主要因素之一,其含量变化与溪蟹种群的生物量、个体大小存在显著的负相关关系.研究表明浙江华西蟹种群对环境理化因素的变化比较敏感,可以用溪蟹种群的动态变化反映水体受污染的程度.

To investigate factors that begot population dynamics of Sinopotamon chekiangense Tai et Song, 16 observations stations were established to measure the item of water quality on the Shuanqing Stream of Tianmu Mountain in Zhejiang Province,and the result showed that the quantities of the population appear notable downtrend. The main individual quantity characteristic of the stream crab population was the small individual, which reduced rapidly when they grew up to the large individual quantity. The quantity and specification of the large individual were playing dominant roles in the biotic mass variety of the population. The population sexes ratio maintains at 3.51~3.91. The heavy metals including Zn~\{2+\}, Gr~\{6+\}, and Gu~\{2+\} appeared in the Shuanqing Stream with certain content(corresponding 0.06 ppm,23 ppb,0.02 ppm), which was one of the main factors that results in the decrease in the quantity and the individual specification of population. The content of the heavy metals showed the distinct negative relation with the amount and individual size of the population. The results of studies expressed that the population of Sinopotamon chekiangense Tai et Song was very sensitive to physical and chemical factor variety of the environment. Therefore, the dynamic state the population variety can be used to reflect the polluted degree of the stream water body.