ABSTRACT
This chapter presents the most important biological information on nematodes in commercially important fish species and the problems they cause for the fishing industry. A solution to the nematode problem, which would be the total cleanness of fish products in regard to nematodes, could theoretically be obtained by physical or biological means, or both hand in hand. Nematodes have a very similar chemical content as flesh of cod, but are a little richer in carbon and copper. In North Sea waters, herringworm infection in pelagic fish species, notably herring, is causing great concern at the moment. The infection level of sealworm in cod seems to be rather similar in Canada and Iceland, but is on the average much lower in British and Norwegian waters. Eggs of sealworms sink, and emerging ensheathed larvae attach themselves by their caudal extremities to the substrata.
