Diversity of haemosporidian parasites in cranes: description of Haemoproteus balearicae and its phylogenetic position within the H. antigonis clade.

Haemosporidian parasites from the genera Haemoproteus, Plasmodium, and Leucocytozoon are significant avian pathogens. This study aimed to identify and characterize these parasites in cranes (family Gruidae), using combined morphological and molecular methods. The results confirmed the presence of Haemoproteus balearicae, redescribed here from Balearica regulorum and associated with cytb lineage hBAREGI210. This lineage, previously assigned to Haemoproteus antigonis, is reassigned to H. balearicae, suggesting possible cryptic speciation within the H. antigonis complex. The findings broaden the known host range and geographic distribution of H. balearicae, detected in captive-born cranes in France and captive cranes housed in conservation facilities in South Africa. Phylogenetic analyses revealed three distinct Haemoproteus clades in Gruidae, corresponding to at least three species, including H. balearicae and lineages representing H. antigonis. These crane-specific parasites may require taxonomic revision as a separate subgenus or genus, pending further studies on their life cycles and vectors. Additionally, several novel cytb lineages of Plasmodium and Leucocytozoon were detected, many unassigned to morphospecies. Notably, the pCATUS05 lineage, a member of the Plasmodium lutzi group previously reported only in the Americas, was detected for the first time in South African cranes, along with Leucocytozoon aff. californicus (lCIAE02), a widespread lineage lacking morphological description. Together, these findings reveal underestimated genetic diversity of haemosporidian parasites in cranes and highlight the importance of combining morphological and molecular data to clarify parasite taxonomy and host associations. This study advances our understanding of avian parasite ecology and systematics, with implications for crane conservation and disease management.