The first record of 4 species of monogenean flatworm on catfish (Clarias fuscus, Hemibagrus spilopterus and Pangasius macronema) in the Dak Lak, Vietnam

Catfish (Order Siluriformes) is one of the largest orders teleosts containing about 4,100 species with highly diverse and distributed worldwide, representing 12% all ∼6.3% vertebrates. are economic ecological importance; many large fish raised or caught for food, small cultured as ornamental. Like other species, monogenean a common ectoparasites on catfish more than 379 recorded. The current study collected 77 individuals three including Hong Kong Clarias fuscus (n = 21), black spotted Hemibagrus spilopterus 17) long barbels pangasiid Pangasius macronema 39)) in Dak Lak 2016 - 2017. Based morphological genetic (18S rRNA gene) characters, this recorded four new dactogyrid hosts Vietnam, which, Thaparocleidus armillatus Mizelleus siamensis P. macronema; Bychowskyella tchangi C. fuscus, Cornudiscoides longicirrus H. spilopterus. Phylogenetic tree constructed 18S sequences from six Genbank showed spp. formed monophyletic clusters sisterly related to remaining species. was clustered separate clade, while M. exhibited paraphyly when grouped genus Thaparocleidus. There need further analysis taxonomic characteristics molecular markers diversity (e.g. Cytochrome oxidase subunit (COI mtDNA), 16S rRNA) determine position