Effects of environmental conditions in the period of early ontogenesis on the formation of defensive behavior in juvenile roach Rutilus rutilus (Cyprinidae)

Abstract

The feeding and defensive behavior of juvenile roach Rutilus rutilus (offspring of one pair of spawners) that were held at early stages of ontogenesis under conditions of differently enriched environments was studied. After the beginning of active swimming (the 12th day upon hatching), roach were reared for 95 days under different environmental conditions (feeding on active or immobilized organisms, the presence or absence of constant water flow, and the presence or absence of a predator), after which comparison of the efficiency of feeding behavior in the presence of a predator in juveniles of different groups was performed. It was established that the degree of environmental richness at early stages of ontogenesis exerts a determining effect on the formation of habits of defensive and feeding behavior. The most efficient behavior was observed in individuals that were held together with the predator during rearing.