An ordination technique for fish diet comparisons

Abstract

The frequency of nine food types in the guts of 58 fish species from the Parana River and itsfloodplain was compared using similarity definition. A synthetic table ordered on the basis of this definition, with fish species on axis y, and food types on axis x, enabled easy reading numerous kinds of information on feeding ecology offish in the catchment. For example: 1) which fish species were generalists, specialists or opportunists, 2) those classified as herbivorous species consumed small amounts of animal food, 3) that fish consumed any food type that contained transformed solar energy and matter, 4) what are food preferences dependent on fish taxonomic affinity. Tlie possibility of employing synthetic tables for investigating spatial and temporal variation in fish diet has also been indicated. © 2000, Parana Institute of Technology Publication.