CO-OCORRÊNCIA DE ESPÉCIES DE PEIXES NAS ÁREAS RASAS DA FOZ DO RIO SÃO FRANCISCO SE/AL

Abstract

CO-OCURRENCE OF FISH SPECIES IN THE SHALLOW AREAS OF SÃO FRANCISCO RIVER MOUTH. The "rules of community assemblage" indicate that competitive interactions would be the main influencing factor in the structuring of biological communities, which generates a non-random pattern of co-occurrence caused by competitive exclusion. Thus, the present study aimed to investigate the co-occurrence patterns in the shallow environments of the mouth of the São Francisco River. Ichthyofauna data from the area were obtained through manual trawling carried out monthly on its banks between May 2017 and April 2018. The data were tabulated in presence/absence matrices and the analyzes were performed through comparisons with null models (random) in a computational environment R, with the EcoSimR package, and through 5000 randomizations. To quantify the co-occurrence patterns, the C-score metric was used, which calculates the species segregation pattern. The results obtained from the simulations showed that the general pattern found did not differ significantly from what was expected at random, indicating that competitive interactions were not the greatest influencing force in the structuring of ichthyofauna in the studied area.