Feeding and Migratory Habits of Arctic Char, Salvelinus alpinus, Indicated by the Presence of the Swimbladder Nematode Cystidicola cristivomeri White

Abstract

The presence of Cystidicola cristivomeri White 1941 in the swim bladder of char indicates the fish have fed on infected, freshwater Mysis relicta which is the essential intermediate host of this parasite. Char younger than 5 yr occur in shallow waters in Stanwell-Fletcher Lake and apparently feed rarely on Mysis as indicated by infrequent infection with C. cristivomeri. Older fish that adopt a migratory habit and go to sea for the summer appear to feed little on Mysis when they return to overwinter in the lake. Small, slow-growing char present in the lake during summer were commonly infected with C. cristivomeri indicating they feed heavily on Mysis. These small fish, which are as old as many migrants, may not participate regularly in the seaward migration. Key words: Arctic char, feeding, migration, nematodes, Cystidicola cristivomeri