caa a22 4500 397552475 CHVBK 20180308164754.0 cr unu---uuuuu 161202e199608 xx s 000 0 eng 10.1111/j.1574-6941.1996.tb00321.x doi (NATIONALLICENCE)oxford-10.1111/j.1574-6941.1996.tb00321.x Spectacular abundance of ciliates in anoxic pond water: contribution of symbiont photosynthesis to host respiratory oxygen requirements [Elektronische Daten] [B.J. Finlay, S.C. Maberly, G.F. Esteban] Very large numbers (3466 ml−1) of ciliated protozoa were found living beneath the oxic-anoxic boundary in a stratified freshwater pond. Most ciliates (96%) contained symbiotic algae (Chlorella spp.). Peak abundance was in anoxic water with almost 1 mol free CO2 m−3 and a midday irradiance of 6 μmol photon m−2 s−1. Photosynthetic rate measurements of metalimnetic water indicated a light compensation point of 1.7 μmol photon m−2 s−1 which represents 0.6% of sub-surface light. We calculate that photosynthetic evolution of O2 by symbionts is sufficient to meet the demand of the host ciliates for 13 to 14 hours each day. Each ‘photosynthetic ciliate' may therefore become an aerobic island surrounded by anoxic water. © 1996 Federation of European Microbiological Societies. Published by Elsevier Science B.V. Ciliate protozoa nationallicence Anoxia nationallicence Photosynthetic symbionts nationallicence Chlorella nationallicence Euplotes daidaleos nationallicence Halteria viridis nationallicence Finlay B.J. Institute of Freshwater Ecology, The Ferry House, Far Sawrey, Ambleside, Cumbria LA22 0LP, UK aut Maberly S.C. Institute of Freshwater Ecology, The Ferry House, Far Sawrey, Ambleside, Cumbria LA22 0LP, UK aut Esteban G.F. Institute of Freshwater Ecology, The Ferry House, Far Sawrey, Ambleside, Cumbria LA22 0LP, UK aut FEMS Microbiology Ecology Blackwell Publishing Ltd 20/4(1996-08), 229-235 20:4<229 1996 20 femsec https://doi.org/10.1111/j.1574-6941.1996.tb00321.x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1111/j.1574-6941.1996.tb00321.x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Finlay B.J. Institute of Freshwater Ecology, The Ferry House, Far Sawrey, Ambleside, Cumbria LA22 0LP, UK aut NATIONALLICENCE 700 1- Maberly S.C. Institute of Freshwater Ecology, The Ferry House, Far Sawrey, Ambleside, Cumbria LA22 0LP, UK aut NATIONALLICENCE 700 1- Esteban G.F. Institute of Freshwater Ecology, The Ferry House, Far Sawrey, Ambleside, Cumbria LA22 0LP, UK aut NATIONALLICENCE 773 0- FEMS Microbiology Ecology Blackwell Publishing Ltd 20/4(1996-08), 229-235 20:4<229 1996 20 femsec Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford