GEOGRAPHICAL VARIATIONS IN ABUNDANCE OF LARVAL ANISAKINE NEMATODES INATLANTIC COD (GADUS-MORHUA) AND AMERICAN PLAICE (HIPPOGLOSSOIDES-PLATESSOIDES) FROM THE GULF OF ST-LAWRENCE

Atlantic cod (Gadus morhua) and American plaice (Hippoglossoides plate ssoides) collected from various sites in the Gulf of St. Lawrence (NAF O divisions 4RST) were examined for larval anisakine nematodes in 1990 and 1992. Sealworm larvae (Pseudoterranova decipiens) were more abund ant in southern Gulf (4T) than in northern Gulf (4RS) cod and plaice. The heaviest sealworm infections occurred in fish from St. Georges Bay , Nova Scotia. Abundance of P. decipiens in cod from St. Georges Bay w as significantly lower in 1992 than in 1990. Anisakis simplex and Cont racaecinea (Contracaecum/Phocascaris spp.) were most abundant in cod f rom the northern Gulf. American plaice were not heavily infected with A. simplex or Contracaecinea. Geographical and temporal variations in abundance of larval anisakine nematodes in fish may reflect distributi on and abundance of the phocid and cetacean definitive hosts and varia tions in water temperatures.