Characterization of the host-parasite relationship of Polymorphidae (Acanthocephala) in Nannopterum brasilianus (Aves, Phalacrocoracidae) in the Soure Marine Extraction Reserve, Pará.

The Neotropical Nannopterum brasilianus is a piscivorous bird feeding on aquatic organisms, can ingest various infectious forms of helminths, such as those from the phylum Acanthocephala. In their adult stage, these parasites attach to the intestinal mucosa of their definitive hosts, causing varying degrees of tissue damage. Between 2020 and 2023, 35 individuals of N. brasilianus were analyzed, and 20 of them (57.1%) presented acanthocephalan infection. Morphological and histopathological analyses identified the species as Southwellina hispida, we described the tissue alterations associated with its presence in detail. The results contribute to the taxonomic knowledge of the parasite and provide important information for diagnosing and monitoring of infections in birds housed at Wildlife Triage and Rehabilitation Centers (WTRC).