New Record of Raillietiella furcocerca (Pentastomida: Raillietiellidae) in Bothrops atrox from the Brazilian Amazon: Morphological Characterization and Infection Sites

Objective This study aims to document the occurrence of Raillietiella furcocerca infecting Bothrops atrox in the Lower Amazon region, State of Pará, Brazil, providing morphometric characterization, infection descriptors, and new insights into extrapulmonary infection sites. Methods A total of 48 B. atrox specimens were examined between 2009 and 2011 (Tapajós National Forest) and 2023–2024 (Santarém and Belterra). Pentastomes were recovered during necropsy, counted, measured, and morphologically identified. Parasitological descriptors (prevalence, mean abundance, and mean intensity) were calculated alongside a literature review of pentastome-snake interactions in the Neotropics. Results Nine host specimens were infected ( $$\:9/48$$ ), yielding an overall prevalence of 18.8%, a mean abundance of 0.48, and a mean intensity of 2.56. Pentastomes were recovered from both the lungs and the coelomic cavity, actively attached to visceral serosa and associated with focal tissue lesions. Conclusion This study provides the first quantitative parasitological baseline for R. furcocerca in B. atrox from the Amazonian biome and confirms the coelomic cavity as a viable antemortem extrapulmonary infection site and provide update literature review and distribution mapping on pentastomids infection in Neotropical snakes.