Distribution of living radiolarians in spring in the South China Sea and its responses to environmental factors  

作　　者：HU WeiFen ZHANG LanLan CHEN MuHong ZENG LiLi ZHOU WeiHua XIANG Rong ZHANG Qiang LIU ShiHao 

机构地区：[1]Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology,Chinese Academy of Sciences [2]University of Chinese Academy of Sciences [3]State Key Laboratory of Tropical Marine Environmental Dynamics, South China Sea Institute of Oceanology,Chinese Academy of Sciences [4]Key Laboratory of Tropical Marine Bio-resources and Ecology, and Tropical Marine Biological Research Station in Hainan,South China Sea Institute of Oceanology, Chinese Academy of Sciences [5]Research Center for Island and Coastal Zone,First Institute of Oceanography, State Oceanic Administration

出　　处：《Science China Earth Sciences》2015年第2期270-285,共16页中国科学（地球科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.41276051,91228207);the National Basic Research Program of China(Grant No.2013CB956102);the Ministry of Science and Technology Foundation Project of China(Grant No.2008FY110100);the National Natural Science Foundation of China(Grant Nos.41076026,40906030)

摘　　要：Using a planktonic net(62-?m mesh) and a Rose-Bengal staining method, we studied the spatial distribution of living radiolarians in spring along two sections of the South China Sea(SCS) in spring and discussed the responses of living radiolarian distribution to tropical environmental factors. Generally, the highest abundance of living radiolarians occurred at the depth range of 25–75 m, where the chlorophyll-a maximum and the highest primary productivity were. In contrast, the maximum living abundance occurred in the top 25 m in cold eddies in the open seas and the abundance decreased with depth. We found that the inhibition effect of changing salinity(due to runoffs) on living radiolarians was much stronger than the promotion effect of mesoscale cold eddies. We observed that large variation of temperature was unfavorable for living radiolarians. The dominant species composition consisted of tropical-subtropical warm species. We identified some indicator species for tropical environments. Living Didymocyrtis tetrathalamus tetrathalamus could be an indicator for tropical surface water or mixed-layer water, and even for tropical oligotrophic water. Living Tetrapyle octacantha could be used to indicate tropical thermocline and eutrophic environment. Living Acanthodesmia vinculata could indicate tropical surface and subsurface waters. T. octacantha and A. vinculata should only be used as indicators for upwelling in the open seas, i.e., far away from river mouths. Living Siphonosphaera polysiphonia preferred to form colonies, which might be related to the effect of warm eddies. Living Cyrtopera laguncula and living Cornutella profunda occurred in the tropical upper layer, even in the surface layer, which suggests that they should not be used as indicators for intermediate and deep waters.Using a planktonic net（62-？m mesh） and a Rose-Bengal staining method, we studied the spatial distribution of living radiolarians in spring along two sections of the South China Sea（SCS） in spring and discussed the responses of living radiolarian distribution to tropical environmental factors. Generally, the highest abundance of living radiolarians occurred at the depth range of 25–75 m, where the chlorophyll-a maximum and the highest primary productivity were. In contrast, the maximum living abundance occurred in the top 25 m in cold eddies in the open seas and the abundance decreased with depth. We found that the inhibition effect of changing salinity（due to runoffs） on living radiolarians was much stronger than the promotion effect of mesoscale cold eddies. We observed that large variation of temperature was unfavorable for living radiolarians. The dominant species composition consisted of tropical-subtropical warm species. We identified some indicator species for tropical environments. Living Didymocyrtis tetrathalamus tetrathalamus could be an indicator for tropical surface water or mixed-layer water, and even for tropical oligotrophic water. Living Tetrapyle octacantha could be used to indicate tropical thermocline and eutrophic environment. Living Acanthodesmia vinculata could indicate tropical surface and subsurface waters. T. octacantha and A. vinculata should only be used as indicators for upwelling in the open seas, i.e., far away from river mouths. Living Siphonosphaera polysiphonia preferred to form colonies, which might be related to the effect of warm eddies. Living Cyrtopera laguncula and living Cornutella profunda occurred in the tropical upper layer, even in the surface layer, which suggests that they should not be used as indicators for intermediate and deep waters.

关 键 词：tropical mesoscale abundance indicator salinity chlorophyll sections stronger Figure environments 

分 类 号：Q178.53[生物学—水生生物学]