The abundance, biomass and composition of pelagic ciliates in East African lakes of different salinity and trophy
Planktonic ciliates were studied in 17 tropical East African lakes of different salinity and trophic status. Oligotrichs (e.g., Strombidium, Strobilidium and Halteria) and scuticociliates (e.g., Cyclidium, Pleuronema, Cristigera), dominated the ciliate communities. Conductivity and trophic status were the most important environmental variables influencing the distribution of ciliate species in East African lakes. Herbivorous oligotrichs were important in oligotrophic and mesotrophic lakes, as they are in temperate and subtropical lakes, but their importance decreased with increasing chlorophyll a concentration and conductivity. On the other hand, the importance of scuticociliates (primarily bacterivores) increased with increasing chlorophyll a and conductivity. Mean ciliate abundance ranged from 2 to 1,220 ciliates.mL-1 while the biomass range was from 1.9 to 1, 900 ~kg C.L-1 respectively from oligotrophic to eutrophic lakes. Abundance and biomass had positive relationships with phytoplankton biomass. The ciliate abundance and biomass were higher than those reported in temperate (Quebec) and subtropical (Florida) lakes of similar trophic status. However, regression models predicting abundance and biomass of ciliates from chlorophyll suggest that temperate (Quebec), subtropical (Florida) and tropical (East Africa) lakes have similar ciliate abundance and biomass per unit chlorophyll except some saline tropical lakes which have very high abundance and biomass of ciliates relative to chlorophyll.
| Main Authors: | , |
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| Format: | Proceedings Paper biblioteca |
| Language: | English |
| Published: |
2006
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| Subjects: | Species diversity, Plankton, Freshwater, Freshwater lakes, Abundance, Biomass, Pelagic environment, Salinity, Community composition, Oligotrophic lakes, Aquatic communities, Regression analysis, Tropical lakes, |
| Online Access: | http://hdl.handle.net/1834/5311 |
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