台湾小孔蛸寄生丛集球虫新种的形态特征及系统发育分析OA北大核心CSTPCD

To explore common parasites in the digestive tract of Cistopus taiwanicus(Mullusca:Octopodidae),particularly those of the Aggregata genus,a new species of parasitic Aggregata verrucosa sp.nov.was found and described in the caecum and intestinal of C.taiwanicus collected in the waters of Zhejiang,Fujian,Guangdong and Hainan.Using light and electron microscopes,it was found that the mature oocyst of A.verrucosa was spherical and sometimes irregular,with a long diameter ranging from 936.96 to 1 563.31 μm and a short diameter ranging from 860.13 to 1 227.85 μm.Mature sporocyst was spherical or slightly subovoid,with a long diameter ranging from 12.87 to 14.24 μm and a short diameter ranging from 12.39 to 13.70 μm.The wall of sporocyst was doublelayered,with a smooth outer layer and a warty inner layer.Each sporocyst contained 4～10 sporozoites.Sporozoites were usually spiral,with a long diameter varying between 12.81 and 16.01 μm and a short diameter varying between 2.02 and 2.62 μm.Molecular phylogenetic tree constructed based on 18S rRNA gene further confirmed that the isolated belonged to the genus Aggregata.The tree highly supported also the phylogenic relationship of the species within the genus,A.sinensis merged first with A.verrucose and then with A.octopiana,A.eberthi and A.octaculeata.