AbstractPeriphyton community comprises bacteria, fungi, protozoa, phytoplankton, zooplankton, benthic organisms, organic detritus and a range of other invertebrates and their larvae. This introductory paper discusses the contribution of periphyton to aquatic productivity and the status of world aquaculture in terms of culture systems, production and trends. Three basic ecological processes in aquaculture can be distinguished: production, consumption and decomposition. The role of periphyton in aquaculture ponds and the three basic food webs (phytoplankton-based, periphyton-based and detritus-based) are reviewed, giving more emphasis on the periphyton-based food web. Fishes and crustaceans can also exploit the detritus-based food webs.