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Various authors have reported on injury to small fishes by achenes of beggar-ticks (Bidem sp.) Reimers and Bond (1966) reported on injury by beggar-ticks to redside shiners, Richardsonius balteatus and young chinook salmon Oncorhynchus tshawytscha. They suggested that presence of beggar-tick plants along banks of hatchery ponds and raceways might be injurious to young of the most aggressive feeders among fish. Allison (1967) described mortality of fingerling coho salmon, Oncorhynchus kisutch, caused by beggar-tick, B. cernuus, achenes. He noted losses of coho salmon 51 to 90 mm in total length held in hatchery raceways. Dead and dying fish had beggar-tich achenes imbedded in gill arches and oral cavities which had resulted in fungus infections.