Abstract |
The purpose of this study was to evaluate the intensity of competition for food among 9 species of stream fishes that primarily eat aquatic invertebrates. The taxonomic and size composition, and numerical abundance of aquatic invertebrates were monitored for one year using drift and benthic samples. Diet data were obtained from stomachs of fishes captured at the same time and place that invertebrate sampling was done. Diet characteristics examined included taxonomic and size composition, number of prey per fish, and diet breadth. The summer-early fall scarcity of invertebrates was especially notable among those greater than 3.6mm long, which comprised the bulk of prey found in fish stomachs. Taxonomic compositions of available invertebrates and fish diets varied markedly among sampling dates, but the use of prey taxa by fishes was not correlated with the availability of those taxa. (Copyright (c) Dr W. Junk Publishers, The Hague 1982.) |