Feeding and growth of the river perch (Perca fluviatilis L.) by the fish-ponds’ zone

The research results on the changes in the nature of nutrition and growth rate of the mass freshwater fish species (river perch in particular) dwelling in close proximity to trout cages is presented for the first time in the national literature. It was revealed that the linear and weight growth of the river perch living in the zone of cages located in the waters of Lake Vokhtozer increases with their age when compared to the growth index of the fish living in natural conditions. Such index performance resulted from the improvement of the fodder base for lacustrine fish and from their more intensive nutrition. Therefore, nutrition of the river perch in focus consisted not only from the natural fodder, but it also included a significant food addition coming from feeding pellets washed away from trout cages during trout feeding.