Supplementary data – Thelohanellus species in common carp – Suhaimi et al. 2026

In contrast, only T. nikolskii, T. hovorkai and actinospore of T. kitauei have been documented in Hungary to date. During a comprehensive parasitological survey on common carp, five Thelohanellus species and three actinospore types were identified from fish farms and Lake Balaton.

Out of them, three new Thelohanellus species (T. serosae n. sp., T. borkhanuddini n. sp., and T. paranikolskii n. sp.) were described by morphological, morphometric, and molecular analyses. The life cycles of T. borkhanuddini n. sp. and T. serosae n. sp. were inferred, with T. borkhanuddini n. sp. confirmed through both molecular data and experimental infection. Notably, the acti-nospore stage of T. borkhanuddini n. sp. was identified in this study, confirming that T. borkhanuddini n. sp. is associated with four distinct neoactinomyxum morphotypes.