A area como preditor da riqueza de éspecies de peixes (Telostei) en lagoas costeiras do leste da América do Sul

PETRY, A. C.; RAMOS GUIMARAES, T.F.; HARTZ, S.M; BECKER, F.G.; VIEIRA, J.P.; GOYENOLA G.; MIRANDA GARCIA, A.; DE VACONCELLOS F.M.; DI DARIO F.; FERNANDES DE MENEZES, R; PELLEGRINI CRAMASCHI, E.M; GONCALVES DE MELO, F. A.; DE MELLO, F. T.; ATTAYDE, J.L.; DÍAZ DE ASTARLOA, J.M.; SARMENTO-SOARES, L. M.; MEERHOFF, M.; MAZZEO, N.; DE SOUZA ROSA R.

Recife

Encuentro; XXI Encontro Brasileiro de Ictiologia; 2015

The relationships between fish composition, connectivity and morphometry of 103 lagoons in nine freshwater ecoregions (FEOW) between 2.83º S and 37.64º S were evaluated in order to detect possible congruence between the gradient of species richness and similarities of assemblage composition. Most lagoons included in the study were smaller than 2 km2, with a maximum of 3,975 km2 in surface area. Combined surface area of all lagoons included in the study was 5,411 km2. Number of species varied locally between one to 76. Ordination of lagoons in a PCA revealed gradients of ecosystem size and connectivity that explained a large amount of variability in species richness. Lagoon area was a good predictor of species richness except at low latitude ecoregions, where lagoons are typically small-sized and not affected by marine immigrants, and where non-native fish species accounted for a significant portion of species richness. Relationships between species and area in small-sized lagoons (< 2 km2) is highly similar to the expected number in each ecoregion, with those systems located between 18.27° S and 30.15° S attaining higher levels of species richness. Similarities in species composition within the Primary, Secondary and Peripheral or Marine Divisions revealed strong biogeographical patterns only for species less tolerant or intolerant to salinity. Further support for the FEOW scheme in the eastern border of South America is therefore provided, and now includes ecotonal systems inhabited simultaneously by freshwater and marine species of fishes.