Abstract:Astronotus ocellatus is a tropical, benthic freshwater fish that originated in South America and is a great favorite for a vast number of aquariums. With the development and extension of the “Belt and Road Initiative” Economic Zone, as an inland area of Xinjiang, the development of ornamental fish is particularly fast, but the rapid development is accompanied by a series of disease problems, such as common parasitic diseases, which are a common factor restricting the development of fisheries. The aim was to investigate the XinJiang common ornamental fish parasite epidemic and classification situation. This study combines the traditional morphological identification methods of parasites with modern molecular biology methods, researching the parasitic monogenean species of A. ocellatus, at the gill site. The subjects were common A. ocellatus selected from the Urumqi Ornamental fish market. From 2016 May to 2017 June, 18 fish samples were collected. The results of the experimental analysis showed that parasites on the gills of A. ocellatus were Gussevia asota, belonging to Dactylogyridae, Ancyrocephalinae, Gussevia. The morphological parameters of the parasite were measured and compared with all the morphological data previously reported on the parasite It was found that there were certain differences between the data measured by different countries. By data retrieval, there is no sequence information of Gussevia Asota molecules in the GenBank database. Therefore, the G. asota 28S rDNA gene sequence was determined and submitted, obtaining GenBank sequence number: MG596661. Phylogenetic tree species from different genera of Ancyrocephalinae were analyzed. Phylogenetic analysis indicated that G. asota was at the top of the phylogenetic tree, with Ligophorus having the closest relationship, and together forming a sister group. And then get together with the parasites of the Cichlidogyrus, as a large branch, the kinship with Ancyrocephalus and Cleidodiscus is the furthest.
