Studies on the chemical nature of feeding stimulants for rainbow trout, Salmo gairdneri Richardson

Rainbow trout trained to operate a demand feeder showed a marked preference for a diet flavoured with a synthetic mixture of chemicals over the unfavoured diet. The gustatory feeding stimulant activity resided in the amino acid fraction and was stereospeciflc for the L‐forms. Certain mixtures of L‐amino acids were stimulatory, while the individual components of the mixtures were inactive or repellent.