Stickleback as a potential paratenic host in the Anisakis simplex life cycle in the Baltic Sea: results of experimental infection.

Anisakis simplex stage 3 larvae found in herring were used to experimentally infect 155 sticklebacks and 6 nine-spined sticklebacks, caught in the Gdynia marina (Gulf of Gdańsk). The larvae were observed in the fish body cavity as early as 24 h after infection, only the sticklebacks being affected. Altogether, 50 live and 2 dead larvae were found in the stickleback body cavity. The infection prevalence and mean intensity were 13.6% and 2.4 larvae, respectively, from 1 to 8 larvae per fish being recorded. It is concluded that the stickleback may serve as a paratenic host for Anisakis simplex.