Paradiplozoon garra n. sp. (Monogenea, Diplozoidae), a new species from Garra surgifrons (Cyprinidae, Labeoninae) in Southwest China.

Abstract

In a parasitological survey conducted in 2025 at a fish farm in Kunming, southwest China, a new diplozoid species was discovered on Garra surgifrons, representing the first record of a diplozoid previously reported from fish within the genus Garra in China. Morphological and molecular evidence confirm that the new species is clearly differentiated from Paradiplozoon bingolensis, the only diplozoid previously reported from Garra fishes. Phylogenetic analyses place the new species at the basal position of Chinese Paradiplozoon species. Considering the natural distribution of its host in Yunnan province and adjacent areas of Myanmar and Laos, southwestern China and Southeast Asia may represent important centres of origin and diversification for East Asian Paradiplozoon species. This study highlights the underestimated diversity, host specificity and biogeographic structure of diplozoids in East Asia and underscores the need for expanded sampling in Yunnan and neighbouring Southeast Asian regions.