The genus Contracaecum belongs to the Anisakidae family which includes parasites of considerable economic and medical importance. Larvae of Contracaecum are associated with a wide variety of freshwater and marine fish. Although there are a significant number of reports that indicate the presence of anisakid in fish from different parts of the world, there are few studies in the central region of Argentina, despite the prevalence observed in recent years. In the present study we provide new records and analyze ecological aspects of anisakid from fish of different aquatic systems with different hydrological characteristics from central Argentina.Atotal of 1402 individuals belonging to nine species, six families and four orders of fish were examinated for nematode parasites. The helminths were found in Astyanax eigenmanniorum (Characidae), Oligosarcus jenynsii (Characidae), Odontesthes bona...