Molecular Genetics in Anisakid Nematodes from the Pacific Boreal Region

Abstract

Molecular studies were carried out on anisakid nematodes from the Pacific Boreal region, causal agents of human anisakiosis. Genetic markers showed that the three taxa detected in this area at the morphological level include at least six reproductively isolated biological species: Anisakis simplex sensu stricto and A. simplex C, belonging to the A. simplex complex; Contracaecum osculatum A, belonging to the C. osculatum complex; and Pseudoterranova decipiens B, P. bulbosa, and P. azarasi, belonging to the P. decipiens complex. Molecular keys for their routine identification are provided. Genetic relationships among members of the A. simplex, C. osculatum, and P. decipiens complexes are given by unweighted pair group cluster analysis (UPGMA) and multidimensional scaling ordination (MDS). Intermediate/paratenic fish hosts and definitive marine mammal hosts recorded for the considered species are provided: these are benthic-benthopelagic for A. simplex s. s. and C. osculatum C, and specialized benthic for P. bulbosa and P. azarasi. Maps are given showing collecting locations and geographic range of the species studied.