Feeding strategy of fish that colonize reservoirs in the Magdalena river basin

Abstract

Construction of dams for hydropower in Andean rivers of Colombia is increasing loss of species of the region. Fish species that persist in these artificial ecosystems are those which find favorable the new conditions for their recruitment. Because feeding is one of the fish life strategies that influence their persistence in reservoirs, we analyzed the stomach contents of the species present in two cascade reservoirs in the Magdalena river basin. The objectives were to describe the diet, to determine their feeding strategies and to evaluate if the rainy season or spatial distribution affects the diet of the fish species. Our results indicate that the fish species Brycon henni and Astyanax microlepis that feed on a wide range of resources that the system offers and adopt a generalist strategy. Also, opportunistic species such as Roeboides dayi and Hoplosternum magdalenae occupied these environments. Climatic seasonality does not influence the feeding habits of the fish species inhabiting the study reservoirs. Knowledge of the feeding habits of fish species is a priority for strengthening the environmental management of aquatic resources of the Andes.