Spatiotemporal distribution of protozooplankton and copepod nauplii in relation to the occurrence of giant jellyfish in the Yellow Sea  

作　　者：王璐 徐奎栋 

机构地区：[1]Institute of Oceanology,Chinese Academy of Sciences [2]University of Chinese Academy of Sciences

出　　处：《Chinese Journal of Oceanology and Limnology》2013年第6期1226-1240,共15页中国海洋湖沼学报（英文版）

基　　金：Supported by the National Basic Research Program of China(973 Program)(No.2011CB403604)

摘　　要：The occurrence of the giant jellyfish, Nemopilema nomurai, has been a frequent phenomenon in the Yellow Sea. However, the relationship between the giant jellyfish and protozoa, in particular ciliates, remains largely unknown. We investigated the distribution of nanoflagellates, ciliates, Noctiluca scintillans, and copepod nauplii along the transect 33~N in the Yellow Sea in June and August, 2012, during an occurrence of the giant jellyfish, and in October of that year when the jellyfish was absent. The organisms studied were mainly concentrated in the surface waters in summer, while in autumn they were evenly distributed in the water column. Nanoflagellate, ciliate, and copepod nauplii biomasses increased from early June to August along with jellyfish growth, the first two decreased in October, while N. scintillans biomass peaked in early June to 3 571 pg C/L and decreased in August and October. In summer, ciliate biomass greatly exceeded that of copepod nauplii （4.61-15.04 ~tg C/L vs. 0.34-0.89 pg C/L）. Ciliate production was even more important than biomass, ranging from 6.59 to 34.19 ~tg C/（L.d） in summer. Our data suggest a tight and positive association among the nano-, micro-, and meso-zooplankton in the study area. Statistical analysis revealed that the abundance and total production of ciliate as well as loricate ciliate biomass were positively correlated with giant jellyfish biomass, indicating a possible predator-prey relationship between ciliates and giant jellyfish. This is in contrast to a previous study, which reported a significant reduction in ciliate standing crops due to the mass occurrence ofN. nomurai in summer. Our study indicates that, with its high biomass and, in particular, high production ciliates might support the mass occurrence of giant jellyfish.The occurrence of the giant jellyfish,Nemopilema nomurai,has been a frequent phenomenon in the Yellow Sea.However,the relationship between the giant jellyfish and protozoa,in particular ciliates,remains largely unknown.We investigated the distribution of nanoflagellates,ciliates,Noctiluca scintillans,and copepod nauplii along the transect 33°N in the Yellow Sea in June and August,2012,during an occurrence of the giant jellyfish,and in October of that year when the jellyfish was absent.The organisms studied were mainly concentrated in the surface waters in summer,while in autumn they were evenly distributed in the water column.Nanoflagellate,ciliate,and copepod nauplii biomasses increased from early June to August along with jellyfish growth,the first two decreased in October,while N.scintillans biomass peaked in early June to 3 571 μg C/L and decreased in August and October.In summer,ciliate biomass greatly exceeded that of copepod nauplii(4.61–15.04 μg C/L vs.0.34–0.89 μg C/L).Ciliate production was even more important than biomass,ranging from 6.59 to 34.19 μg C/(L d) in summer.Our data suggest a tight and positive association among the nano-,micro-,and meso-zooplankton in the study area.Statistical analysis revealed that the abundance and total production of ciliate as well as loricate ciliate biomass were positively correlated with giant jellyfish biomass,indicating a possible predator-prey relationship between ciliates and giant jellyfish.This is in contrast to a previous study,which reported a significant reduction in ciliate standing crops due to the mass occurrence of N.nomurai in summer.Our study indicates that,with its high biomass and,in particular,high production ciliates might support the mass occurrence of giant jellyfish.

关 键 词：Nemopilema nomurai nanoflagellates CILIATES Noctiluca scintillans 

分 类 号：Q958.8[生物学—动物学]