Food consumption by tropical and temperate fish populations: some generalizations

Published estimates of ration and/or food conversion efficiency of various size groups of fishes from 75 different stocks belonging to 56 tropical and temperate species were standardized and re‐expressed as annual fish food consumption (Q) per unit biomass of the age‐structured population (B). Although derived from extremely heterogeneous sources, these estimates of Q/B show surprisingly regular patterns. These allow confirmation of some earlier hypotheses, e.g. that Q/B increases with water temperature and decreases with asymptotic weight. More interestingly, it is shown that the aspect ratio of the caudal fin of fishes that use the carangiform and related swimming modes (i.e. subcarangiform and thunniform) correlates closely with Q/B, when other factors are accounted for. A brief discussion of some implications of these and related results is provided.