The Food of the Brown Trout (Salmo trutta L.)

1. The food of brown trout (Salmo trutta L.) living in rivers has been investigated by the examination of the stomach contents of 133 fish, 104 from the Tees and 29 from the Itchen. 2. The trout is carnivorous and eats almost any animal of a suitable size that presents itself, either in the water or on its surface. 3. The commonest foods, whether surface or sub-surface, are those which are commonest in or on the stream at the time the trout is feeding. 4. The differences in stomach contents of fish from the rivers can probably be completely explained by the differences in the fauna. 5. There is no evidence of specially attractive foods, but it is suggested that Plecoptera of family Chloroperlidae are not eaten by trout.