Diversity and phylogenetic relationships of haemosporidian and hemogregarine parasites in Australian lizards

Abstract

Apicomplexa is a large monophyletic phylum of unicellular, parasitic organisms. Reptiles are hosts to both haemosporidian (Haemosporida) and hemogregarine (Eucoccidiorida) apicomplexan blood parasites. Within reptiles our understanding of their diversity remains limited, with a paucity of information from Australia, despite a high diversity of squamates (snakes and lizards). We provide a preliminary assessment of haemosporidian and hemogregarine diversity occurring in lizards across northern tropical Australia, building on existing data with results from a microscopy and genetic assessment. We screened total of 233 blood slides using microscopy and detected hemogregarines in 25 geckos, 2 skinks and 1 agamid, while haemosporidians were detected in 13 geckos. DNA sequencing of 28 samples of the hemogregarine 18S rRNA (∼900 bp) nuclear gene revealed five lineages of Australian lizard hemogregarines within heteroxenous adeleids. We sequenced 10 samples of Haemosporida mtDNA (cytb & coI: ∼1313 bp) and phylogenetic analysis with 30 previously published sequences revealed that the Australian Haemosporida grouped within the Haemoproteidae but were not supported as a monophyletic clade. Our results demonstrate that there is significant undocumented evolutionary diversity in Australian lizard haemosporidian and hemogregarine parasites, with preliminary evidence of significantly higher infection rates in geckos.