Grazing rate and feeding selectivity of small and large bodied cladocerans in waters from lakes with different salinity and phytoplankton structure  

作　　者：Egor ZADEREEV Tatiana LOPATINA Svyatoslav OVCHINNIKOV Alexander TOLOMEEV 

机构地区：[1]Institute of Biophysics,Krasnoyarsk Research Center,Siberian Branch of Russian Academy of Sciences,Akademgorodok,Krasnoyarsk 660036,Russia [2]Siberian Federal University,Krasnoyarsk 660041,Russia

出　　处：《Journal of Oceanology and Limnology》2023年第4期1341-1351,共11页海洋湖沼学报（英文）

基　　金：supported by the State Assignment of the Ministry of Science and Higher Education of the RF(No.0287-2021-0019).

摘　　要：Cladocera are filter feeders abundant in freshwaters,which consume phytoplankton particles in wide size and taxonomic ranges.The ability of cladocerans to control phytoplankton abundance by grazing is determined by various factors including the characteristics of phytoplankton.Freshwater salinization may reduce the strength of top-down grazing control of phytoplankton because of the detrimental effects of salinity on the grazing intensity of zooplankters.We performed grazing experiments with two species of Cladocera of different body lengths to test their ability to graze on phytoplankton in natural waters differing in salinity and size and taxonomic composition of food particles.Grazing experiments demonstrated that the grazing rate was mostly controlled by the abundance of phytoplankton in the medium.The grazing rate was reduced at salinity ca.above 3 g/L of NaCl in the medium.The lower grazing rate was observed in the medium with larger phytoplankton particles.Both species predominantly consumed phytoplankton particles with a diameter of 6-12μm,which may shift the size distribution of phytoplankton towards a larger average diameter of particles.The taxon-specific feeding was also observed,as both species predominantly consumed diatom algae.Thus,we found that because of grazing,the size and taxonomic characteristics of phytoplankton are shifted towards a less edible community.The detrimental effect of elevated salinity on grazing rate supports growing concern about freshwater salinization negatively affecting water quality,particularly reducing top-down grazing control of phytoplankton.

关 键 词：selective feeding DAPHNIA MOINA top-down control PHYTOPLANKTON SALINITY 

分 类 号：Q948.8[生物学—植物学]