BACKGROUND The aim of most farmers has always been to 1 maximize their gains and break even within the shortest possible period. However, no healthy animal can develop optimally without being adequately well fed. Fish are normally fed collectively without special monitoring of individual fish feeding behaviour or agility. Thus, it must be ensured that an adequate quantity of feed is served periodically without (much) wastage. Feed may be served based on an estimated fish biomass (total body w...