Growth and feeding of juvenile sterlet Acipenser ruthenus L. (Acipenseridae) in a pond after various durations of being preliminarily kept in tanks

It is shown that the level of information richness of the environment in which the juvenile fish were raised at early stages of ontogenesis is one of the determining factors for the development of the most important adaptive patterns of behavior. Minimal values of fullness index, lower body weight, and shorter length, along with a feeding spectrum strongly differing from that in natural conditions, are characteristics of juvenile fish kept preliminarily in the hatchery. The food of this group of fish is dominated by organisms of epibenthos, which may have been detected by the fish using gustatory and tactile receptors. At the same time, the proportion of infaunal invertebrates, the detection of which is only possible using olfaction and electric reception, is minimal. The prolonged development of juvenile fish under conditions of sensory deprivations leads to inadequate behavioral skills, making the process of conventionally reflective “switching” upon the release of such juvenile fish in the wild more difficult.