A new species of parasite on Arctic charr, Salvelinus alpinus (L.), in seawater cages in Scandinavia

Abstract

During a seawater trial with land-locked Arctic charr ( Salvelinus alpinus L.) in northern Norway, fish became infested with metacercariae of the digenean Cryptocotyle lingua Creplin 1825. Prevalence reached almost 85% after 20 days in full strength seawater. In the first intermediate host, the periwinkle ( Littorina littorea), prevalence of infestation with C. lingua in the tidal zone near the charr cage-site was 13.3%. Some important aspects of the biology of C. lingua are briefly reviewed and possible problems caused by the parasite in fish, with special regard to farming, are discussed.