VARIAÇÃO ECOMORFOLÓGICA EM POPULAÇÕES DE Astyanax aff. paranae EIGENMANN, 1914, DE DIFERENTES SUB-BACIAS NO ALTO RIO PARANÁ

Abstract

Astyanax aff. paranae, Eigenmann, 1914, popularly known as redtail lambari, is widely distributed in the Upper Parana River Basin. This wide distribution makes this species of great interest to researchers of several areas (ecology, genetics, taxonomy, among others). One of the areas that tries to understand the ecological dynamics of this species is the ecomorphology, which has as central idea the influence of environmental on morphological adaptations of organisms. Based on this concept, we tested hypothesis that in rivers with different hydrodinamic characteristics influence the ecomorphological aspects of A. aff. paranae populations. We aim to analyze the ecomorphological variation in different lotic environments in the Upper Parana River Basin. For the analysis of the ecomorphological differences, 15 specimens of each lotic environment were used, so that in each individual were taken 26 morphometric measurements and six body areas were calculated. In sequence, 22 ecomorphological indexes were calculated based on areas values and body measurements. Difference were found in ecomorphological indices related to swimming aspects and obtaining resources strategies, evidencing the influence of environmental characteristics on selection of the peculiar morphological characters in each environment. These variations were, mainly, observed in relation among Uberaba River and the streams, Indaia, Biguacu, Jurema, Japira and Caviuna, demonstrating that beyond of the environmental characteristic, the biogeographic factors also provided the populations morphological structure. Keywords: Intra-specific Divergence; Population Ecology; Ecomorphology; Anthropic Impacts; Lambari.