First record and molecular diversity of haemosporidian parasites in Sula leucogaster (Boddaert, 1783) from the southeastern Brazilian coast.

Avian haemosporidian parasites are protozoans transmitted by vectors, belonging to the genera Plasmodium, Haemoproteus, and Leucocytozoon, capable of infecting various bird species. The prevalence of these parasites varies depending on factors such as the habitat and geographical location of the host and vector, as well as across different bird groups. Seabirds typically exhibit low infection rates due to the absence of vectors in marine environments. This study aimed to identify and characterize the molecular diversity of Haemosporida parasites in a population of Brown Boobies (Sula leucogaster) (n = 37) from the Santana Archipelago in Macaé, Rio de Janeiro state. We utilized PCR-based detection methods to confirm the presence of haemosporidian parasites and sequencing (ctyb gene) to delineate the lineages. The results uncovered a notable prevalence (48.6%) of haemosporidian parasites (Plasmodium and Haemoproteus), comprising 12 novel lineages and four previously documented lineages (establishing new host records). Our findings suggest that transmission and infection by these hemoparasites can occur both on and off the island. Overall, this study yields valuable insights into the genetic diversity of haemosporidian parasites in Brown Boobies, enriching our understanding of the ecology and epidemiology of these parasites in seabirds.