Algunos aspectos estructurales y ecologicos de la ictiofauna del sistema de Ibera, Corrientes, Argentina.

Abstract

Recorded 81 species of fishes, in 59 genera, 19 families and 8 orders. The basic structure of the fish fauna was given by sedentary species (able to thrive and reproduce in lentic waters) exclusive in the northern area of the system, while only two typical migratory fishes: Prochilodus platensis and Salminus maxillosus, were present at the southern area. Fish productivity is very poor from the economic point of view, particularly in the northern area, where higher trophic level fishes of low value, such as Hoplias malabaricus, Hoplerythrinus unitaeniatus, Acestrorhamphus jenynsi, Acestrorhynchus falcatus and more frequently Serrasalmus nattereri and S. spilopleura are found. This situation is due to the high concentration of organic matter derived from the flourishing aquatic vegetation. -from English summary