Emerging Pseudoterranova decipiens (Krabbe, 1878) problems in Baltic cod, Gadus morhua L., associated with grey seal colonization of spawning grounds.

摘要

Third-stage larvae of Pseudoterranova decipiens (Krabbe, 1878) and a number of congeneric species (P. krabbei, P. bulbosa, P. azarasi, P. cattani) (McClelland 2002) are anisakid nematodes with the vernacular name cod worm or seal worm. They have a zoonotic potential seen as their ability to infect humans ingesting undercooked infected sh products (Skirnisson 2006). The nal hosts harbouring adult worms in their stomachs and intestine comprise various species of seals. Eggs released from the female worm pass with faeces into the marine environment where they hatch and subsequently third-stage larvae (Kie et al. 1995; McClelland 2002) become ingested by freeliving crustaceans and polychaetes which serve as the rst transport host. These are then eaten by marine sh in which third-stage larvae penetrate primarily the musculature. A large range of sh species may host this parasite stage (Hafsteinsson & Rizvi 1987; McClelland 2002) and thereby serve as the second transport host. When seals ingest infected fish, the two final moults of the worm occur in their stomach wherein worms obtain maturity.