Capacidad de búsqueda de alimento en canales seminaturales de juveniles de trucha común autóctona de origen mediterráneo y de stocks alóctonos cliados en cautividad

Abstract

Stocked brown trouts have reduced ability to obtain food resulting in reduced survival rates. Adaptation to natural environments of farm-reared fishes becomes crucial early after restocking. The aim of this work was to evaluate the self-feeding ability of different strains of juvenile brown trout placed at different densities and in presence or absence of predators. Three different strains of juvenile brown trout were placed for 3 weeks into seminatural ponds at two stocking densities, and in presence/absence of predators. Predators were adult mature trouts stocked prior introducing juveniles. An Atlantic strain from domestic origin was used as control. F2 juveniles from two different native Mediterranean brown trout populations were also used. The presence of food in stomach contents was assessed after necropsy. Feeding ability was decreased in presence of predators and high juvenile densities with important differences among trout strains.