Molecular diversity and biogeography of benthic ciliates in the Bohai Sea and Yellow Sea

作     者：Guihao Li Lei Su Qianqian Zhang Xiaoli Zhang Jun Gong 

作者机构：Key Laboratory of Coastal Environmental Processes and Ecological RemediationYantai Institute of Coastal Zone ResearchChinese Academy of Sciences University of Chinese Academy of Sciences School of Marine SciencesSun Yat-Sen University 

出 版 物：《Acta Oceanologica Sinica》 (海洋学报（英文版）)

年 卷 期：2019年第38卷第2期

页      面：78-86页

核心收录：

学科分类：0710[理学-生物学] 0908[农学-水产] 07[理学] 0707[理学-海洋科学] 

基　　金：The National Natural Science Foundation of China under contract Nos 41522604,31572255 and 31301867 the Strategic Priority Research Program of CAS under contract No.XDA11020702 the CAS Key Research Program of Frontier Sciences under contract No.QYZDB-SSW-DQC013 

主　　题：18S rDNA benthic ciliates diversity biogeography depth decay relationship 

摘      要：This study explored the molecular diversity and biogeography of benthic ciliates in Chinese marginal seas, the Bohai Sea(BHS), North Yellow Sea(NYS) and South Yellow Sea(SYS). From a previous 18S rRNA gene pyrosequencing dataset of the benthic microeukaryotes, we retrieved the sequences affiliated with phylum Ciliophora and analyzed alpha and beta diversities of ciliate communities. We found that BHS had the highest ciliate operational taxonomic unit(OTU) richness than NYS and SYS, whereas the richness was not significantly different between summer and winter. Among all the measured environmental variables, water depth showed consistently the strongest correlations with alpha diversities. Overall, the class Spirotrichea(mostly Choreotrichia and unassigned lineages within the class) dominated the communities in terms of both relative proportion of sequences(77.0%) and OTU richness(66.5%). OTU-level ciliate community structure was significant different among the three basins, but not between the seasons. Structurally, significant differences in relative proportion among the basins were detected for the class Litostomatea, but not for other classes. Partial Mantel tests demonstrated that water depth difference was more important than geographic and environment distances in shaping the community structure of benthic ciliates in the studied area. About 60% OTUs were not assigned at a class or order level and at least 45% OTUs shared a sequence similarity no more than 97% with the described species, indicating a great potential for ciliate species discovery in the offshore sediments. Compared with previous morphology-based surveys, the spatial pattern of ciliate diversity(decreasing from NYS to SYS) is also identified in the present study. Nevertheless, structurally, the dominant class appeared to be Spirotrichea in the sequencing dataset, which differs from previous morphology-based results(dominance of classes Prostomatea and Karyorelictea in biomass). The potential cau