First identification and seasonal dynamics of hepatozoon and microfilariae in diploderma swinhonis (squamata:...

Hemoparasites in reptiles remain underexplored in East Asia, particularly among endemic lizards. We present the first molecular and morphological study of blood parasites in Diploderma swinhonis, a widespread tree lizard endemic to Taiwan. We examined six populations from three locations using an integrated approach combining microscopy (morphology, morphometry) and molecular approaches (Sanger sequencing, phylogenetic analysis). Phylogenetic analyses revealed that Hepatozoon sequences from this host are genetically identical to H. ophisauri, suggesting a broader host and geographic range for this species. In contrast, microfilariae formed a distinct lineage within Oswaldofilariinae, with over 10% divergence from known taxa, indicating a likely undescribed species. Despite high lizard densities in some locations, overall infection prevalence was low (5.3%; n = 1166 ). Relative risk analysis showed significantly higher infection rates in adults than in juveniles, supporting an age-related effect. Seasonal peaks in infection varied between parasite taxa and locations, reflecting differences in transmission routes and life histories. Newly designed primers targeting cytochrome b (for Hepatozoon) and COI (for microfilariae) demonstrated higher detection sensitivity than traditional markers, especially in low-parasitemia individuals. These results highlight the importance of appropriate molecular tools for detecting blood parasites in under-studied reptiles and contribute new insights into the ecological and taxonomic diversity of hemoparasites on East Asian Islands.