图丽鱼寄生破坏古氏虫的形态描述及系统发育

Morphological Description and Molecular Phylogeny of the Gussevia asota Parasite on Astronotus ocellatus

在调查新疆乌鲁木齐市观赏鱼感染寄生虫种类期间,从图丽鱼(Astronotus ocellatus)鳃部采集到一种单殖吸虫,经过形态学比较具有鉴定依据的背腹中央大钩、联接片、交接器等结构后,鉴定为锚首虫亚科(Ancyrocephalinae)的破坏古氏虫(Gussevia asota)。首次测定了破坏古氏虫28S rDNA基因序列(GenBank登录号:MG596661),系统发育分析表明,该虫与鲻鱼虫属(Ligophorus)、嗜丽鱼虫属(Cichlidogyrus)的亲缘关系较近,聚为稳定的独立分支。

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.