During a survey of myxozoan diversity in fishes from Hunan Province, two new Myxidium species were discovered infecting the gallbladder of Sarcocheilichthys kiangsiensis Nichols, 1930 and Sarcocheilichthys parvus Nichols, 1930, in Dongting Lake, China. In both cases, myxospores were observed freely floating in the biles, with no typical plasmodia detected. Morphologically, both of them can be differentiated from previously described congeners by a combination of features, including myxospore dimensions, polar capsule shape, number of polar tubule coils and shell valve striations. BLASTn research indicated that neither species matched any available species in GenBank. The highest sequence similarity for Myxidium kiangsiensis n. sp. was 98.54% with M. asiaticum Chen et al., 2020 (PQ776264), and that for Myxidium parvusis n. sp. was 93.06% with Zschokkella guelaguetza Alama-Bermejo et al., 2023 (OQ888223). This study represents the first record of Myxidiidae infection in Sarcocheilichthys hosts. Phylogenetic analysis based on the obtained SSU rDNA sequences placed the two species in separate subclades interspersed with other Myxidium and Zschokkella species. This topology further corroborates the polyphyletic nature of these two genera.
Dai et al. (Sat,) studied this question.