Molecular Survey of Haemosporidian Parasites in Procellariiformes Sampled in Southern Brazil, 2013-22.

The order Procellariiformes includes several species of seabirds that perform long-distance migrations crossing all the oceans. These movements may contribute to the dispersal and exchange of hemoparasites, such as haemosporidians. There is a lack of studies regarding the order Haemosporida in Procellariiformes, and, to date, only the genus Plasmodium has been reported. This survey investigated the occurrence of the three genera of haemosporidians, Plasmodium, Haemoproteus, and Leucocytozoon, in samples collected between 2013 and 2022 from 95 individuals of 14 species of Procellariiformes from southern Brazil, including live animals in rehabilitation centers, individuals caught as incidental bycatch, and carcasses found along the coast. A total of 171 samples of blood and fragments of liver and spleen were analyzed, with extracted DNA being subjected to a nested PCR followed by phylogeny analysis. All animals were negative for Plasmodium spp. and Leucocytozoon spp., but one Black-browed Albatross (Thalassarche melanophris) and one Manx Shearwater (Puffinus puffinus) specimen were positive for Haemoproteus spp. The sequences obtained from positive seabirds did not show 100% similarity with other known lineages available in the MalAvi database and thus were probably novel lineages. However, one sequence clustered together with Haemoproteus noctuae, a parasite from Strigiformes, while the other was grouped with Haemoproteus columbae, which is classically related to Columbiformes. These results suggest that both positive animals may have become infected when beached or in rehabilitation centers by a spillover of vectors from local birds. This highlights the importance of surveillance of the health of Procellariiformes regarding the possibility of dissemination of new pathogens in different bird populations.

Helminths of South American fur seals (Arctocephalus australis) from the Subtropical Convergence Zone of the Southwestern Atlantic.

Parasites are important components of ecosystems and may contribute to the ecological aspects of their hosts and indicate the integrity of their environment. To identify the gastrointestinal helminths of the South American fur seal, Arctocephalus australis, 52 animals found dead on the Rio Grande do Sul coast, Southern Brazil, were necropsied. All studied animals were parasitized, and 104,670 specimens of helminths from three phyla and 14 taxa were collected. Adult specimens represented five of the identified species: Contracaecum ogmorhini, Adenocephalus pacificus, Stephanoprora uruguayense, Ascocotyle (Phagicola) longa, and Corynosoma australe; and one of the identified genera: Strongyloides sp. Immature forms represented the other eight taxa: Anisakidae gen. sp., Anisakis sp., Pseudoterranova sp., Contracaecum sp., Tetrabothriidae gen. sp., Cestoda gen. sp., Corynosoma cetaceum, and Bolbosoma turbinella. The acanthocephalan C. australe was the most prevalent and abundant parasite, whereas Strongyloides sp. had the highest intensity. This is the first record of the nematode Anisakis sp., digenean S. uruguayense, and acanthocephalan B. turbinella in this host. Trophic generalist species such as A. australis can be good indicators of the composition of the helminth fauna of their ecosystems, indicating the presence of zoonotic parasites transmitted by the consumption of fish.