Abstract
The fish fauna of a subtropical mountain stream in Argentina was surveyed for the first time. The abundance and occurrence of species were explored considering variation in hydrology, seasonality and the abiotic environment. We collected 221 individuals of 23 species from 10 families and four orders. Small sized species and small individuals dominated the fish fauna. The small characid Astyanax saguazu was the most conspicuous species. Hydrology, seasonal changes in water temperature and variation in water conductivity affected the abundance and distribution of fish. Hypobrycon maromba is recorded in Argentina for the first time.
Acknowledgments
This research has been possible due to the support provided by “Bosques Nativos Argentinos para la Biodiversidad” Foundation and its Research Center in Misiones, CIAR (Centro de Investigaciones Antonia Ramos). We particularly wish to mention the honorable labor of the president of the Foundation, Mr. Horacio Juan Schenone. The authors wish to thank the Ministerio de Ecología y Recursos Naturales Renovables de la Provincia de Misiones for logistical support. We are also greatly indebted to Javier Unizony, Gastón Ramos and Eusebio Soto for their invaluable collaboration in the field. JJR acknowledges the financial support from the International Development Research Centre (IDRC) of Canada. EM, EA, NS, JJR and JMDA acknowledge the support provided by the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) of Argentina.