Food habits of char (Salvelinus alpinus) and of brown trout (Salmo trutta) in lakes containing only one of these species are very similar. Both feed on Gammarus, Limnaea, Ephemeroptera nymphs, Trichoptera larvae, terrestrial insects, and small crustacea. When both species are in the same lake, trout feed primarily upon Trichoptera larvae and terrestrial insects, with char feeding on small crustacea. Gammarus and other bottom organisms are still eaten by both, but impounded waters have limited bottom fauna, and in these waters the segregation of char and trout is more pronounced. Trout are territorial and aggressive in comparison to the more pelagic char. In aquaria trout establish hierarchies with the dominant fish showing greater growth and survival. A diagrammatic model is presented to represent the food and habitat segregation observed.