Infection by Contracaecum rudolphii (Nematoda : Anisakidae) in the Neotropic cormorant Phalacrocorax brasilianus, and fishes from the estuary of the Valdivia river, Chile

Seasonal parameters of infection by the nematode Contracaecum rudolphii in the Neotropic cormorant Phalacrocorax brasilianus (Phalacrocoracidae) and t heir relation with feeding and infection in fishes from River Valdivia, Chi le, were determined. The prevalences of infection in birds were similar dur ing seasons, whereas mean intensity and percentages of adult gravid females were higher in spring and summer, respectively. For fishes no seasonal dif ferences were found in infection. Cormorant diet varied seasonally in relat ion to fish prey consumed and this can be related to seasonal differences i n infection parameters of birds. The high infection in birds should be cons idered as a potential risk for salmoniculture.