Taxonomic Study Of Four Freshwater Fish Trypanosomes

Trypanosome is one of familiar haemoflagellates parasited in fish. It is normally transmitted by leeches. Clinical signs of the disease include anemia, general oedema and loss of appetite. It cause the death of fish and serious economic losses. Although ubiquitous, taxonomy and their evolution relationships are uncertain. In this research, we survey the infection condition of the freshwater fish from the middle and lower reaches of Yangtze river in 2013-2014, and took fish trypanosomes from black carp, grass carp, largefin longbarbel catfishas and crucian carps. The use of molecular biology in combination with current morphological data greatly promotes the correct identification of fish trypanosomes and study the taxonomy and phylogenetic relationship within fish trypanosomes. If completed according to research, the species resource of fish trypanosome will be more abundant, the convincing theory concerning correct evaluating the phylogenic and evolution mode of fish trypanosomes from China. Based on morphologica data and molecular data, four species trypanosomes have been re-described. The main results are as following.1.The trypanosome from the blood of grass carp were be found in Niushan lake Wuhan. we descript the trypanosome based on current morphological data. According to the morphological data, we suggest that the trypanosome we got should be identified as Trypanosoma ctenopharyngodoni after the comparison between them and other trypanosomes. And Trypanosoma ctenopharyngodoni was redescribed using 13 morphometric characterizations. 2.During the parasite fauna investigation, the freshwater fish trypanosome was isolated from the blood of black carp in Niushan lake Wuhan. we descript the trypanosome based on current morphological data. According to the morphological data, we suggest that the trypanosome we got should be identified as Trypanosoma mylopharyngodoni after the comparison between them and other trypanosomes. And the trypanosoma was redescribed using 13 morphometric characterizations. 3.The trypanosome from the blood of Largefin longbarbel catfish were be found in Sichuan. In the present study, we descript the trypanosome based on current morphological data. This trypanosomes had great similarity in morphology with Trypanosoma hemibagri. And the trypanosoma was redescribed using 13 morphometric characterizations. 4.During the parasite fauna investigation, the freshwater fish trypanosome was isolated from the blood of crucian carps in Niushan lake Wuhan. we descript the trypanosome based on current morphological data. According to the morphological data, we suggest that the trypanosome we got should be identified as Trypanosoma pingi after the comparison between them and other trypanosomes. And the trypanosoma was redescribed using 13 morphometric characterizations. SSU r DNA sequences were compared. The results show that the sequence alignments revealed that the present SSU rDNA sequence is most similar to that of Trypanosoma pseudobagri(94.62%), and the morphology characteristics have obvious differences. So Trypanosoma pingi and Trypanosoma pseudobagri might be the different genotypes.