Ecological Studies Of Nanoflagellate And Ciliate In The East China Sea

Nanoflagellates and ciliates are key components of protists and play a crucial role in material cycle and energy flow of microbial food web.Horizontal and vertical distribution variation in the abundance and biomass of protists,size and oral diamiter of ciliates,ciliate community structure and the reponse of nanoflagellates and ciliates communities to environmental factors were investigated during three seasons between December 2015 and August 2016.The main results are as follows:1)In winter of 2015,a total of 49 species(37 Oligotrichida,8 Tintinnida and 5 others species)were observed.Five dominant species were found.The ciliates of size in 20-40 ?m and oral diameter in 10-20 ?m were dominant categories.The nanoflagellates of size in 2-5 ?m dominated nanoflagellates communities.The reponse of biological factors to environmental factors were not significant.2)In spring of 2016,a total of 75 species(52 Oligotrichida,14 Tintinnida and 9 others species)were observed.Five dominant species were found..The ciliaters of size in 20-40 ?m and oral diameter in 5-10 ?m were dominant categories.The nanoflagellates of size in 2-5 ?m dominated nanoflagellates communities.The reponse of abundance and biomass of nanoflagellate and ciliates to depth and salinity were significant,but not to temperature.3)In summer of 2016,a total of 71 species(51 Oligotrichida,15 Tintinnida and 5 others species)were observed.Seven dominant species were found..The ciliaters of size in 10-20 ?m and the ciliates of oral diameter in 5-10 ?m were dominant categories.The nanoflagellates of size in 2-5 ?m dominated nanoflagellates communities.The reponse of abundance and biomass of nanoflagellate and ciliates to depth,salinity,temperature,dissolved oxygen and nutrients were significant.4)The abundance and biomass of nanoflagellate and ciliates and community structure of ciliates were characterized by a clear seasonality dynamic.The dominant species that existed in all of three seasons was Strombidium bilobum.The abundance of HNF was "top-down" controlled by abundance of ciliates was clearly revealed in the model of Log HNF-Log Bac abundance,in all of three seasons.The constitutent of water mass of three seasons were different.The difference of community structure of nanoflagellate and ciliate in different water mass were significant.The majority factor which influenced the distribution of community structure of nanoflagellate and ciliate was water mass.