Effects of the eye fluke Diplostomum spathaceum on the energetics and feeding of Arctic charr Salvelinus alpinus
Abstract:In the present study, effects of the trematode eye fluke Diplostomum spathaceum infection and parasite-induced cataract on energetic costs and feeding of hatchery-bred one-summer-old Lake Saimaa Arctic charr Salvelinus alpinus were examined. The energetic effects (measured as oxygen uptake) of acute eye fluke infection on S. alpinus were negligible, but in the chronic infections mean oxygen consumption of infected fish was significantly higher than that of controls. Feeding capability of S. alpinus was studied in aquarium experiments, and uninfected healthy-eyed fish reacted to zooplankton more rapidly and caught zooplankton with better success compared to individuals with cataracts in the same school. The results suggested that to compensate energetic costs and impaired feeding capability caused by eye fluke, cataract-bearing fish spend more time foraging, which may result in increased predation risk.
Document Type: Regular Paper
Affiliations: Ecological Research Institute, Faculty of Biosciences, University of Joensuu, P. O. Box 111, 80101 Joensuu, Finland
Publication date: December 1, 2008