Abstract:To prevent and control the invasion of non-indigenous species,meanwhile,to protect ecological security and biological resources in Zhoushan sea area,we set up 11 sampling sites to investigate the biodiversity of intertidal organisms in 2010 and 2012,respectively.The study collected a species of barnacle in Yangshan deep water port for the first time in 2010.This species has a rhombic aperture,porominent joint ridge and membranous basis.We could accurately identify the species as Chthamalus challengeri by its four teeth of mandible,legible incision of maxillule and quadrate sheet cirrus.The genetic distances and population genetic structure of C.challengeri were investigated using mitochondrial cytochrome C oxidase subunit Ⅰ(COⅠ)gene sequences.The population genetic distance of samples collected from Zhoushan sea area and COⅠ sequences downloaded from NCBI is 0.994%,which shows a great possibility for the new species from Zhoushan sea area to be the species of C.challengeri.The result of Neighbor-Joining tree showed the same verdict with population genetic distance result,which provides corroborative evidence for the identification of the new species from Zhoushan sea area.The results of ecology survey showed that C.challeneri were collected in minority area of Zhoushan from Yangshan deep water port,Shengsi,Qushan,Daishan and Zhujiajian,and the density of it ranged from(6±2)to(28±11)ind./m2.In 2012,we could collect it from all the sampling sites of Zhoushan archipelago,the densities for the 6 sampling sites which had collected C.challengeri in 2010 ranged from(55±8)to(39 533±6 243)ind./m2 in 2012.The densities of other 5 sampling sites ranged from(16±4)to(20 000±4 000)ind./m2.This study elaborates the research status of C.challangeri as a non-indigenous species in Zhoushan sea area from various angles of its biological characteristics,population historic distribution area,introduced geschichte and spread status.