The Range, Prevalence, and Abundance of Codworm (Pseudoterranova decipiens) in Atlantic Cod (Gadus morhua) in the Gulf of Maine

Pseudoterranova decipiens (sensu stricto) (Krabbe, 1878), also known as codworm or sealworm, is a nematode marine parasite of many different species of invertebrates, fish, and seals. In the North Atlantic, the gray seal (Halichoerus grypus) and harbor seal (Phoca vitulina) are the most significant definitive seal hosts of P. decipiens. Many commercial fish species such as Atlantic cod (Gadus morhua) are reported as intermediate hosts. Despite the issues that infection of commercial fish with these larvae presents to the fishing industry and the public health sector, no studies of the ecology of P. decipiens have specifically targeted the Gulf of Maine (GOM). It is likely that the southern limit of P. decipiens has not been characterized. The present study aims to determine the range of P. decipiens in the GOM by assessing its prevalence and abundance in Atlantic cod and to determine the relationship between prevalence and abundance of P. decipiens in Atlantic cod and proximity to major seal haulout sites. This will be accomplished through morphological and molecular identification of nematode worms collected from whole fish samples of Atlantic cod throughout the GOM. This study will serve as a baseline for future management of P. decipiens in this region.