Behavioural responses to various chemical incentives in hybrid beluga x Russian sturgeon (Huso huso x Acipenser gueldenstaedtii) fry

Behavioural contact feeding responses to various chemical incentives were s tudied in hybrid beluga x Russian sturgeon (Huso huso x Acipenser gueldenst aedtii) fry. Solutions of 29 amino-acids (10-2 M); aqueous extracts of vari ous vegetable, animal and microbiological components of commercial fish die ts (30 min infusion of 100 mg in 100 mi), and various artificial and natura l substances were tested. The most attractive amino-acids were lysine, meth ionine and alanine. Most of the dietary extracts tested did not stimulate f eeding behaviour, indicating that widespread commercial sturgeon diets (suc h as ST-07 or ST-04Az) consist of components with little attractiveness for sturgeon fry. In most cases extruded diet components stimulated more bites than granulated ones. Among the diet components, only fish protein concent rate (FPC), dry milk and krill meal stimulated feeding behaviour. Flavour e nhancers such as concentrated low molecular weight nitrogenous substancs (C LMNS), sodium glutamate, and "Finnstim" all stimulated feeding behaviour of fry. Some of these substances are recommended as flavour enhancers in stur geon diets.