Seasonal diets of mooneye, Hiodon tergisus, in the Assiniboine River

Abstract

Stomach analyses of 665 mooneye (Hiodon tergisus) netted from the Assiniboine River during a 12-month period indicate that mooneye fed mainly on insects. Corixids occurred in about 80% of the stomachs that contained food and formed the bulk of the ingesta. Other insects eaten were coleopterans, ephemeropterans, dipterans, odonatans, plecopterans, and hymenopterans. Amphipods, crayfish, and plant materials were other items taken.Mooneye fed during each month of the year but vernal (April–June) and autumnal (September–November) peaks occurred. There were significant seasonal variations in percentages of stomachs with food and in the mean weight of stomach contents. Monthly mean food weights were significantly greater for adult male mooneye during the autumnal peak.