Abstract: Yili River system hosts a diverse fauna of fishes and parasites. Gymnodiptychus dybowskii is a rare and endangered aboriginal cold-water fish inhabit in the Yili river system, Our research identified a new species Gyrodactylus gymnodiptychi n. sp. isolated from G. dybowskii in the Kunes River (Yili River, China). Morphological comparisorrevealed identifiable differences between the new species and other parasites, including Gyrodactylus aksuensis.and Gyrodactylus tokobaevi, which are two known parasites living in G. dybowskii inhabit in the Aksu River westof Frunze (Kyrgyzstan), as well as Gyrodactylus montanus living in Shizothorax intermedius inhabited in theTadzhikistan or Uzbekistan. Especially, the dorsal bar of G. gymnodiptychi n. sp. was raised at both ends with ahollow, and its hamulus roots were curved inward. The BLASTN search of GenBank did not detect any other ITS1.5.8S-ITS2 rDNA sequences same as G. gymnodiptychi's. Using the Bayesian Information and Maximum Likelihood methods to analyze the ITS1-5.8S-ITS2 rDNA gene sequences, we constructed phylogenetic trees for G. gymnodiptychi n. sp. Accordingly, our morphological and molecular research indicated that G. gymnodiptychi n. sp. was not only a new species of parasites but also the first Gyrodactylus member identified in the Yili River in China.
Keywords: Gyrodactylus gymnodiptychi n. sp., Gymnodiptychus dybowskii, Monogenea, Phylogenetic analysis, China
