Fauna parasitária de Aylacostoma spp. (Gastropoda: Hemisinidae) em uma bacia Neotropical: distribuição geográfica e novos registros com base em dados moleculares.

Abstract

Mollusks constitute one of the most diverse phyla among invertebrates, with gastropods standing out due to their high adaptive success. In continental aquatic ecosystems, these animals play fundamental ecological roles. They act in food webs and as first intermediate hosts in the biological cycles of digenean trematodes. These parasites are characterized by the presence of suckers and complex life cycles, with some species having zoonotic potential. However, it is important to consider the difficulties in identifying digenean trematodes at certain stages of their life cycle, highlighting gaps in knowledge about the larval stages and biological cycles of many species. Therefore, techniques based on molecular markers become important tools in the identification and characterization of digenean trematode species at all developmental stages. Among the most widely used markers for this group are those based on mitochondrial genes, such as the cytochrome c oxidase subunit I (COI) gene, and those related to nuclear genes, such as 28S rRNA. For this study, mitochondrial and nuclear sequences were obtained with the aim of characterizing and molecularly identifying digenean trematode species associated with Aylacostoma in the Upper Paraná River basin. Nine taxa were characterized, yielding novel molecular data for the species. The results expand the knowledge about the geographic distribution of digenean trematodes and about the diversity of parasite species in intermediate hosts.