Anisakis larvae (Nematoda: Anisakidae): retrospective morphological, morphometric, biogeography, and taxonomic status analysis

Abstract The family Anisakidae includes parasite genera that are important for public health due to their zoonotic potential. Among these, the genus Anisakis contains some of the most prevalent parasites found in fish that are consumed and commercially exploited in Brazil. Thus, this study aimed to investigate records of the presence of third-stage larvae of Anisakis spp. fish parasites found in Brazilian territory, focusing on their morphological, morphometric, biogeographic, and prevalence aspects over a period of 40 years. This analysis identified the presence of Anisakis larvae in 18 orders, 2 groups, 40 families, 60 genera and 69 species of infected marine, brackish and freshwater fish, demonstrating the lack of specificity to a particular group, which was also evident in the different morphometric data, as well as in the site of infection and habitat of the hosts, with predominantly marine fish being the most infected.. The presence of different Anisakis morphotypes highlights parasitic biodiversity and reinforces the need for taxonomic studies of these zoonotic agents found in fish consumed as food. Special attention should be given to the Amazonian ichthyofauna, located in one of the aquatic ecoregions considered a research priority in Brazil, with the identification of these zoonotic parasites being a matter of food security and public health.