Molecular and morphological characterization of hemoprotozoan infections in imported reptiles in Taiwan

Hemoprotozoa are blood-borne protists with complex life cycles. Despite their high prevalence, diversity of hemoprotozoa in reptiles remains poorly documented. We analyzed blood smears, histopathology, and PCR-amplified 18S rDNA and cytochrome oxidase c subunit I (<i>COI</i>) sequences from ten reptiles representing five species imported into Taiwan. In <i>Varanus macraei,</i> elongated intraerythrocytic gamonts and hepatic merogonic stages were documented. The near full-length 18S sequence formed a deeply divergent lineage consistent with a novel taxon, for which we propose <i>Hepatozoon macraei</i> sp. nov. In <i>Ctenosaura quinquecarinata</i> and <i>Ctenosaura similis</i>, hemococcidian sporozoites were identified morphologically. Based on 18S rDNA phylogenetic inference, the lineages derived from <i>C. quinquecarinata</i> were placed within <i>Lankesterella</i>. In addition, all haplotypes from <i>C. quinquecarinata</i> clustered with a previously reported <i>C. similis</i> lineage based on <i>COI</i> phylogenetic inference. In <i>C. quinquecarinata</i>, intraerythrocytic <i>Hepatozoon</i> were present, and 18S phylogenies formed a well-supported clade closest to <i>H. ophisauri</i>. In <i>Basiliscus plumifrons</i>, trophozoites and meronts of <i>Plasmodium</i> were detected. Analyses of partial 18S rRNA and <i>COI</i> sequences each placed the newly generated <i>Plasmodium</i> sequence as a separate lineage that did not cluster with available reference sequences. In <i>Stigmochelys pardalis</i>, intraerythrocytic gamonts matched <i>Hepatozoon fitzsimonsi</i> morphologically and phylogenetically, representing the first record from Taiwan. The current study provides molecular and morphological evidence of multiple hemoprotozoan genera infecting reptilian pets in Taiwan, highlighting the need for further investigation into the diversity, host-pathogen relationships, and potential impacts on native herpetofauna in the global exotic pet trade.