ecological significance of grazing on planktonic populations of cyanobacteria by the ciliate Nassula

• Published in: The New phytologist Vol. 114; no. 2; pp. 247 - 263
• Main Authors: Canter, H.M, Heaney, S.I, Lund, J.W.G
• Format: Journal Article
• Language: English
• Published: Oxford, UK Cambridge University Press 01.02.1990; Blackwell Publishing Ltd; Blackwell
• Subjects: Algae; Algal blooms; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Autoecology; Biological and medical sciences; Cantors; Ciliophora; Cyanobacteria; Eurychasma; food chain; Fundamental and applied biological sciences. Psychology; Grazing; host-parasite relationships; Lakes; marine fungi; marine science; mucilage; mucilages; Nassula aurea; Parasitism; phytoplankton; Plankton; planktonic cyanobacteria; Podophrya; Population density; population dynamics; Population growth; predation; predator-prey relationships; Protozoa. Invertebrata; relationships; Protozoa; Host parasite relation; Europe; England; Great britain; United Kingdom; Freshwater environment; Phytophagous; Animal plant relation; Cyanobacteria; Lakes; Bacteria; Ciliata; Density dependence; Population dynamics; Mucilage; Population density
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.1990.tb00397.x

Observations on the grazing of planktonic cyanobacteria (blue-green algae) by the ciliate Nassula aurea Ehr. are described from three lakes in the English Lake District, Cumbria. Substantial declines in blooms of Aphanizomenon flos-aquae f. gracile Ralphs ex Born, et Flah. due to feeding by N. aurea are documented from Esthwaite Water and Blelham Tarn. The differential grazing by Nassula only on certain cyanobacteria present in the lakes is discussed in relation to the production of cyanobacterial mucilage. Density-dependent predator/prey relationships are considered together with the significance of grazing episodes on interannual variability of cyanobacterial populations and their periodicity. A suctorian (Podophrya sp.) which parasitizes Nassula and a biflagellate fungus (Eurychasma sp.) which parasitizes the Podophrya are illustrated and briefly described.