Abstract:
In order to determine the Gyrodactylus species in China, we applied morphological and molecular approaches to identify specimens of Gyrodactylus collected from 6 principal goldfish farming areas. Four Gyrodactylus species, including G. kobayashii, G. gurleyi, G. longoacuminatus and G. sp., were identified with morphological measurements. According to rDNA its sequence alignment, 2 species of Gyrodactylus were identical to G. kobayashii and G. longoacuminatus with a similarity of higher than 99.1%. One species of Gyrodactylus was identical to G. gurleyi with the similarity higher than 98.2%. The other Gyrodactylus species had low similarity to all the currently available sequences, with the relatively high similarity of only 91.0% to G. kobayashii. The results of Phylogenetic analysis indicated that these three Gyrodactylus species were clustered with G. kobayashii, G. gurleyi and G. longoacuminatus, respectively. The fourth Gyrodactylus species clustered in a separate clad. All the 4 Gyrodactylus species in goldfish belonged to G. (Limnonephrotus), and they were distant from G. elegans that belonged to G. (Gyrodactylus). G. kobayashii was found in all sampling areas and was dominant in Guangzhou, Wuhan and Zhengzhou with a proportion of more than 60%. G. gurleyi was found in 5 areas except for Zhengzhou, and dominated in Haikou, Nanjing and Shanghai with the percentage of higher than 50%. G. longoacuminatus and G. sp. formed a small proportion. The results suggested that G. kobayashii and G. gurleyi were the most common Gyrodactylus species in goldfish, and G. gurleyi and G. longoacuminatus were the newly reported in China.