Among the fish and insects which constitute the principal foods of the larger predaceous fish of Cultus lake, B.C., young sockeye salmon (Oncorhynchus nerka) are of outstanding importance. In general, the consumption of sockeye is proportional to their abundance, though it may be in some cases modified in the direction of less than proportional predation upon the smaller populations. Consumption of alternative foods increases greatly in years when sockeye are scarce.