Studies On Species Classification Of Tetraonchus And Ancyrocephalus, The Population Ecology And Phylogeneties Of The Two Species In Fish Of Ergis River

We have surveyed the Tetraonchus and Ancyrocephalus of fish with seven times fiom April 2009 to April 2013 year in Ergis River of China. The observation and drawing comparison of the parasites by the polyvinyl alcohol dyeing. The result showed that the Tetraonchus had the two species about the Tetraonchus monenteron and Tetraonchus borealisn. Tetraonchus monenteron had been only found in the gills of Esox lucius, their infection rate reached the highest of 44.8% in spring and aggregated distribution in different body length. Tetraonchus borealis had been only esle found in the gills of Thymallus arcticus. Ancyrocephalus paradoxus was found in the gills of Lucioperca lucioperca, their infection rate had reached the highest 37.50% in autumn, the grthering distribution in summer. Ancyrocephalus percae had been only found in the gills of Perca fluviatilis, their infection rate of 15~20 ? body length(L) of Lucioperca lucioperca reached the lowest 15.71%, the highest 32.86% and aggregated distribution.Morphological identification in the verification results to ensure species identification accuracy, 18S-ITS1 sequencing of Tetraonchus monenteron and Ancyrocephalus paradoxus have compared with GenBank as the 98.99% 591/597, 100% 522/522 severally, and been determined the same parasite. Tetraonchus monenteron in the branch where more independent. The genetic relationship of Ancyrocephalus paradoxus and Ancyrocephalus percae have been the nearest from the same branch in the Evolutionary Tree of System.In order to understand the genetic relationship of parasites between the genera. 28 S sequencing of Tetraonchus monenteron and Ancyrocephalus paradoxus have been compared with GenBank as the 99.69% 646/648, 98.78% 568/573. The genetic distance of Ancyrocephalidae and Dactylogyridae been the nearest distance 0.296 ~ 0.656, Ancyrocephalinae and Ancylodiscoidinae been the nearest phylogenetic relationship more closer but the Tetraonchus monenteron relatively independent and Ancyrocephalus paradoxus from the two major branches.