Tri-hooked monogenean parasite (Heteronchocleidus buschkieli; Ancyrocephalidae: Heteronchocleidinae) isolated from ornamental fish (Colisa lalia) imported into Iran [İran'a yurt di{dotless}şi{dotless}ndan getirilen süs bali{dotless}klari{dotless}ndan (Colisa lalia) İzole edilen üç-kancali{dotless} monogenean parazit (Heteronchocleidus buschkieli; Ancyrocephalidae: Heteronchocleidinae)]

Parasites imported with dwarf gourami fish may present risks,both to native fish populations and to the aquaculture industry. heteronchocleidus buschkieli bychowsky,1957 is an important anabantidae fishes parasite. a large number of imported anabantid fish originate from southeast asian countries. the objective of this study was to investigate the occurrence of infection with monogenean parasite in dwarf gourami fish imported from southeast asia into iran. in this study,a total of 400 dwarf gouramies were randomly selected from aquaria containing this fish imported from southeast asia into iran. after euthanizing,the gills were removed and arches and skin were examined microscopically for monogenean parasites. heteronchocleidus buschkieli (monogenea: ancyrocephalidae) was the only monogenean parasite identified morphologically in 120 of 400 (30%) imported fish. the infected fish were lethargic and had hyperemic gills with small skin lesions. prevalence,abundance and mean intensity of infection for four years were 0.3,30 and 30±1.96,respectively. to the author's knowledge,this is the first report of dwarf gourami infection with h. buschkieli in iran. in order to prevent the introduction of this parasitic pathogen from imported fishes,we recommend imported fishes should be examined and treated before domestic distribution and quarantine practices should be implemented.