Herbivory in the tilapia <i>Oreochromis niloticus:</i> a comparison of feeding rates on phytoplankton and periphyton

Abstract

A quantitative comparison of the grazing behaviour of young Oreochromis niloticus feeding on the planktonic cyanobacterium Microcystis aeruginosa and a periphytic community dominated by the cyanobacterium Oscillatoria sp., determined that biomass ingestion rates of fish filter‐feeding on planktonic cyanobacteria were significantly lower than those surface‐grazing on periphyton. Comparisons of published laboratory data on filter‐feeding with field data on algal ingestion rates suggest that filter‐feeding may be a relatively unimportant method of ingesting algae.