Ecosystem approach of pejerrey (Odontesthes bonariensis) cage culture in Pampean shallow lakes (Argentina)

GARCIA DE SOUZA JAVIER RICARDO; SOLIMANO PATRICIO; MAIZTEGUI TOMÁS; BAIGÚN CLAUDIO RAFAEL MARIANO; CLAPS MARÍA CRISTINA; COLAUTTI DARÍO CÉSAR

Granada

Congreso; ASLO Aquatic Sciences Meeting; 2015

Universidad de Granada

Considering the relationship between pejerrey (Odontesthes bonariensis), the most important native fish from Argentinean inland waters, and the zooplankton community, it has been carried out experiments of extensive cage culture in Pampean shallow lakes. It was attempted to identify and evaluate the factors that influence over the pejerrey production, and the manners in which they affect growth and survival. Key variables were identified as extrinsic (limnological features and seasonality) and intrinsic (age, size and stocking density). It was found a positive relationship between lake´s zooplankton biomass and growth of pejerrey reared in floating cages: the higher growth rates were obtained with larger zooplankton biomass and a better representativeness of species of a considerable size (copepods and cladocerans larger than 0.7 mm). The experiments allowed to set the necessary quality of natural food, which is dynamic and depends on the key variables mentioned. It also demonstrated the plasticity of pejerrey, which can change its trophic niche according to food availability, and indicate the possibility to improve the efficiency of this aquaculture method, optimizing the use of resources, managing the intrinsic key variables.