Ligulosis associated with mortality in largescale suckers

Investigations of a fish kill at an irrigation reservoir in the Deschutes River basin, Oregon, documented at least 153 dead largescale suckers Catostomus macrocheilus, all heavily infected with large Ligula intestinalis (Cestoda). Moribund fish nearshore were similarly infected, with no evidence of secondary disease or infection. Morbidity and mortality in all cases was probably due to severe mechanical damage to internal host organs resulting from infection with multiple, large L. intestinalis. The pathology of L. intestinalis documented in largescale sucker in this study contrasts sharply with previous accounts and may represent a new and emerging disease for largescale suckers. Copyright 2002 The Fisheries Society of the British Isles. Published by Elsevier Science Ltd. All rights reserved.