Riauwaty, MorinaKurniasih2013-05-302013-05-302013-05-30978-602-9115-20-8wahyu sari yenihttp://repository.unri.ac.id:80/handle/123456789/3503The aim of study was to know the prevalence of Clinostomum infections in Climbing perch (Trichogaster trichopterus) in Riau, Indonesia. Trichogaster trichopterus from Sail river, Riau were collected, and examined for Clinostomum infection. Encysted metacercariae of Clinostomum were excysted with a needle and fixed in 10% formalin. Speciemens were stained with Semichon’s Acetocarmine, dehydrated in alcohol series, cleared with xylene and mounted in entellan. The Clinostomum parasites were observed under a stereomicroscope and numbers recorded. Clinostomum identification was based on Chung et al 1995. The result showed that 18 of 105 observed climbing perch were infected by Clinostomum sp. The infected fish had total length between 5,6-11cm, while the weight range was 2,01-28,64 g. Based on the sexuality, the male fish was infected by the Clinostomum sp. (76,2%) more than the female (23,8%). Prevalence of Clinostomum sp. infection to the fish was 17,1%, and the infestation was between 1 to 29 worm per location. This research was the new record of Clinostomum sp. in Climbing perch (Trichogaster trichopterus) as second intermediate hostfound in Riau, IndonesiaenPrevalenceTrichogaster trichopterusmetacercariae ClinostomumriauOther