Integrated Taxonomic Analysis of Biomphalaria (Hygrophila: Planorbidae) from the Brazilian Amazon

Identification of individuals of Biomphalaria is a challenging task, since morphological aspects alone are not sufficient to distinguish between species, which share many similar characteristics. However, the accurate identification of species of Biomphalaria is crucial for monitoring of schistosomiasis, since these species are intermediate hosts of the parasite Schistosoma mansoni, which causes the disease, which is prevalent in the north region of Brazil. In this context, the objective of this study was to identify specimens of Biomphalaria that occur in Mapiri Lake, in the lower Amazon region, in Santarém, Pará, Brazil. An integrated approach was used for identification of specimens of Biomphalaria, which included embryological and morphological analyses (comparison of diagnostic characteristics between species of the genus), as well as molecular assays using the Sanger sequencing method with dideoxy chain termination, as a method to reinforce the precision of species identification. The results establish the first record of B. amazonica in the state of Pará. This species has a development cycle consistent with that observed for other species of the genus Biomphalaria but possesses morphological characteristics that make accurate identification at the species level difficult, which reinforces the need for the molecular analyses. The first record of B. amazonica in the state of Pará in this study enlarges the distribution area of this species in Brazil, which demonstrates the importance of research focused on the identification of species of Amazonian mollusks as an auxiliary tool that can be used to combat schistosomiasis.