@article{article, keywords = {molluscs, intermediate hosts, Biological control, Parasitic Infections, Trematodes}, author = {Oliveira N and Gomes D and Oliveira B and Severino A and Helmold P and Caldeira R and Thiengo S and Massara C and Geiger S and Coelho P}, title = {Survey of malacofauna in a historically schistosomiasis-endemic area in Brazil: fifty years after environmental interventions targeting Biomphalaria species}, abstract = {

Freshwater molluscs play important functions in aquatic ecosystems, contributing to trophic nets and reflecting the environmental conditions of a given area. Despite their relevance, knowledge about the distribution and structure of these communities remains limited, particularly in areas under anthropogenic pressure. In this context, ongoing control programs against human schistosomiasis have motivated controlling actions, targeting the intermediate hosts: different mollusc species, whose impacts on freshwater ecosystems remain still poorly understood. Baldim, a municipality in the Metropolitan Region of Belo Horizonte, has historically been endemic for schistosomiasis in Minas Gerais, Brazil..Between 1969 and 1973, control actions were implemented using the molluscicide niclosamide (Bayluscide, Bayer 73) and biological control through the introduction of specimens of the genus Pomacea. The present study aimed to evaluate the current diversity of the malacofauna in the area, with an emphasis on species of the genus Biomphalaria, to investigate ecological aspects, and to identify its associated trematode parasites. Freshwater mollusc surveys were conducted between June 2022 and August 2023. A total of 2,085 molluscs were collected, representing 16 species, including the first record of Biomphalaria tenagophila (an intermediate host of Schistosoma mansoni). Also, we found one native species Idiopyrgus souleyetianus and three exotic and invasive species Melanoides tuberculata, Physella acuta, and Corbicula largillierti. Populations of Pomacea maculata remained restricted to the former areas of introduction, with no significant impact on populations of Biomphalaria spp.. Different trematode larvae were detected, including cercariae of the types Echinostoma, Monostoma, Xiphidiocercaria, Stringiocercaria, Parapleurolophocerca, and Gymnocephala, demonstrating the diversity of parasites in the region. This study contributes to the knowledge on the freshwater malacofauna in the area. It also highlights the need for continued research on molluscs and the trematodes associated in these aquatic environments, both, before and after control interventions in their natural habitats.

}, year = {2026}, journal = {Brazilian Journal of Biology}, volume = {86}, pages = {1 - 13}, month = {10/2026}, publisher = {FapUNIFESP (SciELO)}, issn = {1678-4375, 1519-6984}, url = {https://www.scielo.br/j/bjb/a/CwJM7Br9QHR3sjCJm7zXLLM/?format=pdf\&lang=en\&ilang=en}, doi = {10.1590/1519-6984.305465}, language = {ENG}, }