Resumo

SCIPIONI, N. et al. Análisis de la diversidad de peces en ambientes asociados al río Paraná en el área de la represa de Yacyretá. Rev. vet. [online]. 2016, vol.27, n.2, pp.86-92. ISSN 1669-6840.

The diversity of the fish fauna in the alluvial valley of the Paraná River, between the cities of Ituzaingó and Puerto Abra, area of influence of the Yacyretá dam, was evaluated. Data used range from 2004 to 2015. Campaigns are conducted every three months (four per year), covering all seasons. Fish were collected using electrofishing equipment. Four representative zones of the longitudinal gradient of the river were chosen. alpha diversity was measured by the Shannon-Wiener index, the true diversity index by Jost, the Simpson diversity index, and Simpson dominance index, while the beta diversity was assessed with the Whittaker index and Jaccard coefficient. A correlation analysis between the values of diversity and distance from the dam, was also performed. A total of 173 fish species, distributed in 11 orders and 32 families, were identified. Species diversity of different areas, their abundance range curves and curves of accumulation of species, tend to decrease downstream of the dam. Alfa diversity indices used show the highest values in the area of Itá Ibaté, halfway position to the dam. Beta diversity was moderate and similar between environments. The results suggest differences in the structure of the fish community in floodplain environments that respond to environmental changes related to the longitudinal gradient from Ituzaingó as closer to the dam point to Puerto Abra as the most distant point.

Palavras-chave : fish; species diversity; Paraná River; Yacyretá dam; Argentina.

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