Pomacea figulina (Spix in Wagner, 1827) (Mollusca, Gastropoda) como uma espécie-modelo para ensaios ecotoxicológicos e monitoramento ambiental de microplásticos em águas doces

Abstract

This dissertation analyzed the occurrence and effects of microplastics in the gastropod mollusk Pomacea figulina (Spix in Wagner, 1827), to evaluate its potential as a bioindicator in aquatic environments. The work was organized into a general introduction, three articles, and conclusions. In the first article, a protocol for rearing the species in the laboratory was developed, testing different diets to identify the ideal conditions for growth and survival. This is an essential step, given the difficulties encountered in waters with low hardness, which compromise the integrity of the shells. The results demonstrated that the combination of feed with kale was the most efficient regime, while the diet composed exclusively of kale resulted in high mortality. The second article characterized microplastics present in specimens collected from a tributary (Rio Pirajibu-Mirim - 23°29'24.2" S; 47°23'06.3" W) of the Sorocaba River, analyzing the color, shape, size, chemical characterization, and abundance of the eliminated particulates. Fibers and fragments were identified as the predominant components, and it was found that clearance is not linear, suggesting temporary retention in the digestive tract. The third article consisted of controlled exposure experiments (72 h) to polyethylene microplastics at different concentrations (10% and 20%), allowing the evaluation of elimination patterns and the possibility of bioaccumulation. Taken together, the results demonstrate that P. figulina presented characteristics favorable to biomonitoring, such as regional abundance, capacity to ingest plastic particles, and sensibility to impacted environments. The dissertation provided data on the maintenance of the species under laboratory conditions and on the effects of microplastics on freshwater mollusks, presenting it as a promising model for studies of plastic pollution in continental ecosystems.