A new Batrachospora species (Apicomplexa: Sarcocystidae) from Duttaphrynus toad in Taiwan

Coccidia of amphibians remain poorly studied despite high host diversity, with critical gaps in integrative taxonomic documentation. This study describes Batrachospora jiunnshiowi n. sp. (Apicomplexa: Sarcocystidae), a novel coccidian parasite infecting the Asian black-spined toad (Duttaphrynus cf. melanostictus) in Taiwan. Morphological characterization revealed sporulated oocysts (mean L × W = 15.9 × 14.1 μm; L/W ratio = 1.1; n = 50) with ellipsoidal sporocysts (10.8 × 8.0 μm; L/W = 1.35; n = 66) lacking Stieda bodies and containing unique drop-shaped sporozoites—an autapomorphy distinguishing it from congeners. Phylogenetic analyses of all datasets (18S ribosomal RNA, cytochrome c oxidase subunit 1, concatenated sequences) robustly placed within the subfamily Hyaloklossinae, demonstrating paraphyly relative to B. caeruleae despite morphological conformity to Batrachospora diagnostic criteria. Prevalence was 13.3 % (2/15 hosts) in the eastern lineage of D. melanostictus, representing the first molecularly characterized coccidian in this host. The integrative taxonomic approach combining morphometrics, host specificity, and multi-locus phylogenetics validates its status as a new species. The discovery underscores significant undocumented coccidian diversity in synanthropic amphibians and advocates expanded surveillance to clarify host-parasite coevolution.