The Relation Between Growth and Food Consumption in the Brown Trout ( Salmo Trutta )

The relation between the amount of food consumed and the growth made is one of considerable ecological importance, though the study of it has hitherto been confined almost entirely to domesticated animals living on artificial foods. In the case of fishes there is a good deal of information available in American and German literature on the food requirements of fish in fish farms and hatcheries but practically none on the relation between the amount of natural food eaten and the growth rate. Dawes (1930–1) studied this relation for the plaice, using chopped mussel (Mytilas edulis) as food, and recently Surber (1935) has described an experiment, similar to those on which this paper is based, on feeding brook trout (Salvelinus fontinalis) and rainbow trout (Salmo gairdneri) with Gammarus fasciatus.