Brachygalaxias bullocki (Regan, 1908) is a fish species endemic to Chile, and its distribution is restricted from Concepcion to ChiloeIsland. A survey conducted during January 2007, involving 26 fish from the Maullo´n River in Southern Chile, shows that infracommunities richness ranged from 0 to 5 with a mean species richness of 2.3 (SD ¼ 1.3). Nine species of parasites were recorded, and 8 constitute new records of parasites for B. bullocki: Ichthyophthirius sp., Trichodina sp., Epistylididae, Myx- obolus sp., Myxidium sp., Tylodelphys sp., Stephanoprora uruguayense, and Diplodon chilensis.