An isopod as intermediate host of cod-worm

Abstract

Ten cod (Gadus morhua), caught at 30-50 m depth in the Froan area (64°N) on the Norwegian coast in October 1977, held an average of 53 cod-worm (Phocanema decipiens) larvae in their muscles. Stomach contents included fish, amphipods and isopods. Of 87 isopods, 84 were identified as Idothea neglecta and from these one P. decipiens larva was recovered. The findings suggest that I. neglecta is a significant food resource for coastal cod, and that this isopod also is a first intermidiate host of cod-worm.