Molecular characterization of Moniezia expansa (Rudolphi, 1810) (Cestoda: Anoplocephalidae) from a captive common eland (Tragelaphus oryx) in Taiwan.

The genus Moniezia comprises globally distributed parasitic cestodes that cause significant economic losses in domestic ruminants, yet its molecular characterization in wildlife remains limited. This study provides the first molecular confirmation of M. expansa in zoo animals in Taiwan. Specimens were obtained from a captive-born common eland (Tragelaphus oryx) and a domestic goat (Capra hircus); those from the eland underwent morphological examination of gravid proglottids, while all samples were analyzed genetically. Using the 18S ribosomal RNA, 28S ribosomal RNA, cytochrome c oxidase subunit 1, and NADH dehydrogenase subunit 1 (nad1) gene regions, we found identical strains of M. expansa in both the common eland and domestic goat in Taiwan, suggesting a local infection event. Notably, the eland-derived sequences clustered within lineages predominantly reported from Caprinae hosts, providing preliminary evidence of a potential spillover event, which aligns with the known broad host specificity of M. expansa. Haplotype network analysis further identified a novel nad1 haplotype within our sampled dataset and revealed high genetic diversity, which may support the hypothesis of complex expansion history of M. expansa. These findings underscore the value of molecular tools in clarifying parasite ecology in mixed wildlife-livestock settings and highlight the need for ongoing surveillance in zoological institutions.