Fish diversity and community structure of Yaboti stream, Yaboti Biosphere Reserve, Misiones, Argentina

The present study was carried out in the Yaboti stream located in the Parana Forest, in urgent need for conservation. The research aimed at determining the structure and dynamics of the fish community in the Yaboti stream. Data collection was focused on the following parameters: diversity, similarity, dominance, reproductive and feeding aspects. Four experimental fishing campaigns in 3 sections of the stream were organized between November 2006 and November 2007. Ten fishing nets were used and the activity was developed during the different seasons of the year. Diversity (H') was 3.55 bit and no significant difference (p >.05) was observed. 1,327 individuals from 65 species were caught. The most outstanding similarity was between the high and the low basin where the dominant species were Apareiodon piracicabae (A. piracicabae) and Leporinus striatus (L. striatus). The highest abundance and specific diversity occurred in the lower basin during winter. Species such as A. piracicabae, L. striatus, Pimelodus absconditus, Steindachnerina brevipinna and Acestrorhynchus pantaneiro (A. pantaneiro) were the dominant ones most of the year. Insects and vegetal matter of allochthonous origin were the most consumed resouces. The lower basin was of greater reproductive activity, registering the largest RGS and mature A. pantaneiro, A. piracicabae and L. striatus females. Reproductive activity increased during winter and spring. All Rights Reserved (C) 2015 Universidad Nacional Autonoma de Mexico, Institut de Biologia.