The Community Structure And Species Diversity Of Shrimp And Crab In The Set-net Fishing Area Off The Coast Of Zhoushan

Based on2007-2009the data of shrimp and crab in Zhoushan coast of precipitationweb prawns area, we analysed the species composition of crabs and shrimp inZhoushan coast, the changeable situation of the dominant species, the index ofdiversity, clustering. The results show that25kinds of shrimp were collected inZhoushan coast. They are belonging9families and18genera, among them thePortunidae number of species is penaeidae，which belonged to12genera3fromfamilies.There are10dominant species of shrimp,they are Exopalaemon annandalei，Palaemon gravieri，Parapenaeopsis hardwickii，Alpheus japonicus Miers，Leptochelagracilis Stimpson，Parapenaeopsis tenella，Alpheus distinguendus de Haan，Aceteschinensis Hansen， Solenocera crassicornis， Metapenaeus joyneri. There are8dominant species of crabs.they are Carcinoplax vestita，Charybdis japonica，Portunustrituberculatus，Charybdis hellerii，Charybdis bimaculata，Ovalipes punctatus，Hemigrapsus sanguineus，Portunus argentatus.Combined with the shrimp researchdata in previous years，we can infer that the interannual variability of shrimpdominant is obvious； Through the comparison crab dominant data betweenZhoushan coast and offshore waters of the Mid-southern East Sea，we can infer thatthere are obvious difference in the dominant species.The species rich index of crabs and shrimp in the research aera and all the years isvery high，the Shannon-Wiener diversity index (H ’) and Pielou species evennessindex (J ’) does not change significantly，the whole is almost same.Though clusterwith the data of shrimp web prawns，we can deduce that there are much difference inthe spring、winter and summer、autumn，there are much difference in the Shengsi、Putuo and Hanzhou bay of the Species distribution；Though cluster with the data ofweb prawns crab，we can deduce that there are difference in the summer、winter andspring autumn，there are much difference in the Shengsi、the north of Zhoushan andHangzhou bay、Putuo.