Parasite loss or parasite gain? Story of Contracaecum nematodes in antipodean waters

Contracaecum spp. are parasitic nematodes belonging to the family Anisakidae. They are known to be able to have highly pathogenic impacts on both wildlife (fish, birds, marine mammals) and humans. Despite having the most numerous species of any genus of Anisakidae, and despite a wide range of publications on various aspects of their pathogenicity, biology and ecology, there are no recent comprehensive reviews of these important parasites, particularly in the Southern Hemisphere. In this article, the diversity of Contracaecum parasites in Australian waters is reviewed and possible anthropological impacts on their populations are discussed. The abundance and diversity of these parasites may have been under-reported due to the inadequacy of common methods used to find them. Populations of Contracaecum parasites may be increasing due to anthropogenic factors. To minimise the risk these parasites pose to public health, preventive education of stakeholders is essential. There are still many unknown aspects of the parasites, such as detailed information on life cycles and host switching, that will be interesting directions for future studies.