Molecular characterization of swallow haemoproteids, with description of one new Haemoproteus species.

Haemoproteus species (Haemosporida, Haemoproteidae) are cosmopolitan bird blood parasites, which often cause relatively benign infections in adapted avian hosts, but severe and even lethal haemoproteosis might develop due to internal organ damage if these pathogens inhabit non-adapted (wrong) hosts. Haemoproteids of swallows (Hirundinidae) remain fragmentarily investigated, with only two haemoproteid species reported in this bird family, which members are cosmopolitan, diverse and inhabit various terrestrial ecosystems, particularly in tropical countries. This study describes and provides molecular characterization of Haemoproteus parahirundinis n. sp. (cytochrome b lineage hHIRUS05), parasite of the most broadly distributed swallow, the Barn swallow Hirundo rustica. Gametocytes, gametes and ookinetes of the new species were examined and compared with other haemoproteids described in swallows. The phylogenetic analysis indicated the existence of a largely undescribed Haemoproteus species diversity in birds of the Hirundinidae and also suggests that all lineages of haemoproteids reported in swallows are transmitted by Culicoides biting midges, but not louse flies of the Hippoboscidae, which often inhabit their nests. The biting midges should be the first targets in vectors research of swallow haemoproteids. This study indicates existence of Haemoproteus species, which are readily distinct based on morphological characters of their blood and sporogonic stages, but differ only negligently in partial cytochrome b sequences, the main markers broadly used in molecular characterization of haemoproteids. That calls for further taxonomic research on haemoproteid in swallows, many species of which are endangered or even threatened with extinction because of habitat degradation.