Seven species of the genus Trichodina Ehrenberg, 1838 were identified during a sampling programme of twenty freshwater fish species from approximately sixty sites in Scotland, England and Wales. Species found include: Trichodina acuta Lom, 1961 from Cyprinus carpio L., Carassius auratus L., Oncorhynchus mykiss (Walbaum), Salmo trutta L. and Phoxinus phoxinus L.; Trichodina domerguei Wallengren,...