Abstract:

Procambarus clarkii is native to southern USA and northern Mexico.As an exotic invasive species,it has been well known throughout domestic and overseas that P〖KG-*3〗.clarkii has made a severe threat to natural biodiversity of common freshwater aquatic organisms.Alien invasive species have become a serious environmental issue throughout the world.Therefore,the research collected specimens from 12 localities out of 9 counties (cities) covered by basin of the Poyang Lake,afterwards we measured various morphological features and analyzed the data,then finally probed the current possible distributing status of P〖KG-*3〗.clarkii.The preliminary survey indicated that P〖KG-*3〗.clarkii had been dominant species around basin area in the Poyang Lake,moreover,it presented broadly vigorous growth over the whole lake and the situation was likely getting worse,which had produced potential negative effects on other aquatic species and the ecosystem; and the yield of indigenous Macrobrachium presented a reducing trend year by year.Results from morphological cluster analysis showed that P〖KG-*3〗.clarkii from the Poyang Lake could be divided into two groups; the first group covered the area of Xingzi,Yongxiu,Gongqing counties and the second one prevailed in Poyang,Xinjian,Yugan counties etc.The survey indicated there was no any obvious cross distribution phenomena between these two groups,nevertheless,they were not two totally distinct groups yet based on current research result.Meanwhile,this study also proposed some feasible preventive suggestions on the invasive species,which should be considered for adjusting the ongoing policy of lakecontrolling and fish moratorium.The current period of time of fish moratorium (from April to June) also almost covers the peak season of P〖KG-*3〗.clarkii growing,developing and breeding.There might be applying a specific fishing policy aiming at P〖KG-*3〗.clarkii in the Poyang Lake which can only allow fisherman to catch P〖KG-*3〗.clarkii freely for controlling its amounts and potential population booming,not for other aquatical species at the same period time during fish moratorium.Furthermore,we still need to do more biological fundamental research work of P〖KG-*3〗.clarkii and some systematic research involving its biological invasion mechanism