The importance of Protozoa in controlling the abundance of planktonic algae in lakes

The Freshwater Biological Association, Ambleside, England
Biological Journal of the Linnean Society (Impact Factor: 2.54). 06/2008; 179(2):203 - 219. DOI: 10.1111/j.1095-8312.1968.tb00978.x

ABSTRACT Apart from ciliates, there are other protozoans which can form an important element in the herbivorous zooplankton of lakes.The protozoans discussed in this paper feed on colonial algae. They can greatly reduce the numbers of certain Chlorophyta in Windermere, Esthwaite Water and Blelham Tarn, lakes in the English Lake District.A very short period, often 7–14 days, can suffice for the destruction of more than 99% of an algal population.Experiments with a species of Pseudospora showed that it would only ingest one out of six green algal species, although, in nature, Pseudosporae which are morphologically similar to this species have been observed in all these algae.The importance of such protozoans, and of parasitic fungi, has been underrated or neglected in studies of the quantitative relationships between primary and secondary production in the plankton.

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