Distribution characteristics of Nemopilema nomurai(Scyphozoa:Rhizostomeae) and zooplankton in East China Sea

Based on the data obtained from the investigations in the summer and autumn of 2003-2005 in East China Sea,the biomass distribution of giant jellyfish,Nemopilema nomurai and zooplankton,and the ecotypes and interspecies changes of dominant zooplankton species were analyzed.The results showed that N.nomurai mainly distributed in the area of 29°00'-34°00'N in summer,and in the area of 31°00'-34°00'N in autumn.From 2003 to 2005,the biomass and distribution area of N.nomurai decreased,although it still transferred from north East Sea to Yellow Sea from summer to autumn.The high biomass of zooplankton was mostly found at the edges of the concentrated region of N.nomurai.There was a negative correlation between N.nomurai and zooplankton in distribution pattern.The main dominant species of zooplankton were Calanus sinicus and macrura larva in summer,and C.sinicus,Sagitta enflata and Doliolum denticulatum in autumn.The biomass changes between N.nomurai and zooplankton showed a good correlation,and the level of biomass,together with the main dominant composition of zooplankton,could be considered as the important indicators of N.nomurai blooms.