Fish diversity along spatial gradients in the Itaipu Reservoir, Paraná, Brazil

• Main Author: Oliveira,E. F.
• Publication Date: 2004
• Other Authors: Goulart,E., Minte-Vera,C. V.
• Format: Article
• Language: eng
• Source: Brazilian Journal of Biology
• Download full: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1519-69842004000300008
• topic: fish assemblages; diversity; spatial gradients; neotropical reservoirs

Local and turnover patterns of fish diversity in the Itaipu Reservoir were evaluated and related to a longitudinal or river-dam gradient (composed of riverine, transitional, and lacustrine zones) and to transversal or upstream-downstream gradients of the tributaries (composed of lotic and lentic stretches of tributaries and reservoir shores). Thirteen stations were sampled quarterly during 2 years. A total of 85 fish species were caught. Local (alpha) and turnover (beta) patterns of fish diversity showed significant differences in reservoir spatial gradients. Along the longitudinal gradient, total and alpha-diversity were the highest in the riverine and transitional zones of the reservoir and lowest in the lacustrine zone. Along the transversal gradient, total and alpha-diversity increased from the lotic stretches of the tributaries to the reservoir shores. The lotic and lentic stretches of the tributaries presented the highest beta-diversity values, indicating heterogeneity in species compositions among the sub-basins. We conclude with recommendations for reservoir management based on the results of this study.