Sistemática e Evolução - Pôsteres - 29/11/2023 - 15:30 h às 16:30 h

This study analyzed the genetic diversity of two soft-bodied meiofauna worms that measure, respectively, about 0.3 mm and 0.2 mm long, Saccocirrus pussicus (Marcus. E,1948) and Kata leroda (Marcus. E,1950). The meiofauna is a diverse and ecological group of organisms that has a role in nutrient recycling, organic matter decomposition and benthic food chain. The aim of this study is to understand the distribution of genetic variability of these overlooked species, as they require specific methods of collection, preservation and identification. Samples were collected from four sandy beaches on the southeast coast of Brazil and preserved in 99% alcohol. The 28SrRNA and 16SrRNA regions were amplified by PCR and population and demographic analyses were performed. The results were compared to verify if there is a relationship between life history and population genetic variability. The results indicated that the species present population genetic structuring, for Kata, 28SrRNA FST was 0.55143, and in Saccocirrus, 16SrRNA FST’ is 0.51355. These results may indicate that there are barriers that prevent or reduce dispersion or gene flow between them. In addition, the species present different levels of intrapopulational genetic diversity, which may reflect different reproductive and adaptive strategies. The results contribute to the knowledge of meiofauna diversity and evolution and to the conservation of marine biodiversity.