Six species of birds of the family Sternidae are often found on the southern coast of South America. Sterna trudeaui, S. hirundinacea, Thalasseus maximus, T. acuflavidus and Sternula superciliaris are South American residents and Sterna hirundo, a Nearctic migrant. At least 500 species of nasal mites have been described around the world, and Rhinonyssidae is the most diverse family. These mites are bloodsucking endoparasites that inhabit the respiratory system of birds. This study aimed to report on occurrences of nasal mites in Sternidae on the southern coast of Brazil. Of the 106 birds analyzed, 8.5% (9 birds) were parasitized by nasal mites. This report provides the first record in the Neotropical region for two mite species, Sternostoma boydi and Larinyssus orbicularis parasitizing Thalasseus acuflavidus and Sternula superciliaris. No nasal mites were found in Sterna trudeaui or Thalasseus maximus. One host individual (T. acuflavidus) was parasitized by two species of nasal mites, S. boydi and L. orbicularis.

Acuariidae nematodes are normally found in the digestive tract of aquatic birds, including Procellariiformes. Were examined Calonectris borealis (n = 4), Diomedea exulans (n = 1), Macronectes giganteus (n = 8), Thalassarche chlororhynchos (n = 5), Thalassarche melanophrys (n = 15), Procellaria aequinoctialis (n = 4), Puffinus gravis (n = 2) and Puffinus puffinus (n = 6), collected on the southern coast of RS, Brazil. A total of 16 birds (35.5%) were parasitized by two species of Acuariidae. Stegophorus diomedeae and Seuratia shipleyi were identified, with prevalences of 26.1% and 21.7%, respectively. Few studies on nematodes in Procellariiformes have been conducted. Here, the acuariids Seuratia shipleyi in Calonectris borealis and Procellaria aequinoctialis and Stegophorus diomedeae in Diomedea exulans, Procellaria aequinoctialis and Thalassarche chlororhynchos were reported for the first time.

Pathology and morphometry of Hystrichis acanthocephalicus (Nematoda) from Phimosus infuscatus (Pelecaniformes) in southern Brazil AbstractSpecies of Hystrichis are parasite nematodes of the digestive tract of aquatic birds in South America, Europe and Asia. In Brazil, Hystrichis acanthocephalicus has been reported in Phimosus infuscatus. There are few data on the morphometry of this species and there are no reports on pathological conditions that it causes. Therefore, the purpose of this study was to report morphometric data from H. acanthocephalicus and describe the pathological effects of this parasite on the Phimosus infuscatus proventriculus. Thirty gastrointestinal tracts of P. infuscatus were examined to search for nematodes and H. acanthocephalicus occurred in 83% of hosts. Were measured the total length and body width of males and females, and of their respective cuticular spines, esophagus, spicules and eggs, and the internal and external diameter of copulatory bursa. Histopathological examination revealed parasitic structures in the proventriculus from the lumen (anterior end) to the outer layers of the organ (intermediate and posterior parts), in which we observed inflammatory reaction with infiltration of heterophils, hemorrhage and hemosiderin. The results of this study of histopathology, morphometry and parasitological indices are the first ones reported to H. acanthocephalicus and should contribute to the identification and recognition in cases of outbreaks in the Neotropical region.Keywords: Aquatic bird, helminths, pathology, morphometry. ResumoEspécie de Hystrichis são nematoides parasitos do trato digestório de aves aquáticas, na América do Sul, Europa e Ásia. No Brasil, foi registrado Hystrichis acanthocephalicus, em Phimosus infuscatus. Existem poucos dados sobre a morfometria e não há registros relativos à patologia desta espécie. Portanto, o objetivo deste estudo foi relatar dados morfométricos de H. acanthocephalicus e descrever os efeitos patológicos deste parasito no proventrículo de Phimosus infuscatus. Foram examinados trinta tratos gastrintestinais de P. infuscatus para a pesquisa de nematoides e H. acanthocephalicus ocorreu em 83% dos hospedeiros. Mediu-se o comprimento total e largura do corpo de machos e fêmeas, dos espinhos cuticulares, do esôfago, dos espículos, dos ovos, respectivamente, e a largura interna e externa da bolsa copuladora. Nos exames histopatológicos foram encontradas estruturas parasitárias no proventrículo, desde o lúmen (porção anterior) até as camadas mais externas do órgão (porções intermediária e posterior), nas quais se observou reação inflamatória com infiltrado de heterófilos, presença de hemorragia e deposição de hemossiderina. Os resultados desse estudo sobre histopatologia, morfometria e índices parasitológicos são os primeiros relatados para H. acanthocephalicus e deverão contribuir para a identificação e reconhecimento em casos de surtos na região Neotropical.

Birds act as hosts for a variety of parasites, many of these are unreported. The literature provides scant information on the helminth fauna of Phimosus infuscatus. The presence of helminths were investigate in 28 birds from Pelotas, Capão do Leão, and Rio Grande in Rio Grande do Sul. The preparation and identification of helminths followed protocols. Prevalence (P%), mean intensity of infection (MII), and mean abundance (MA) were estimated. The following helminths were found: Hystrichis acanthocephalicus , Dioctophyme renale (larva), Porrocaecum heteropterum , Baruscapillaria sp., Aproctella carinii , Paradeletrocephalus minor, and Cyathostoma sp. (Nematoda); Echinostomatidae gen. sp., Tanaisia valida, and Athesmia sp. (Trematoda: Digenea) and Megalacanthus sp. (Cestoda). The most prevalent species were H. acanthocephalicus, P. heteropterum, Megalacanthus sp., and Echinostomatidae gen. sp. and Megalacanthus sp. had the highest MII and MA. There was a significant difference in the prevalence of H. acantocephalicus between female and male bird hosts. We report Echinostomatidae gen. sp., T. valida, Athesmia sp., Cyathostoma sp., A. carinii, P. minor, D. renale (larva), Baruscapillaria sp., and Megalacanthus sp. for the first time in P. infuscatus in Brazil.

The phylum Apicomplexa is divided into four main groups, which include important genera such as Babesia, Theileria and Neospora, which are responsible for diseases that can affect domestic and wild animals. The objective of this study was to ascertain occurrences of Neospora caninum, Babesia sp., Babesia microti, Piroplasmida sp. and Theileria equi in wild mammals in the southern region of the state of Rio Grande do Sul, Brazil. Twenty-two wild mammals that were found dead as roadkill in this region were necropsied, and organ fragments were collected. The spleen was used for DNA extraction and for parasite detection via PCR. Studies carried out through molecular analysis contribute towards identifying the elements that cause new cases of disease and the emergence of potential reservoirs and vectors. Thus, through these molecular studies, the following were recorded for the first time in Brazil: Neospora caninum and Babesia microti in Cavia aperea, Babesia sp., Theileria equi and Piroplasmida sp. in Procyon cancrivorus; and T. equi in Galictis cuja.