Genetic identification of Anisakis larvae in European hake from Atlantic and Mediterranean waters for stock recognition

The occurrence of seven species of the larval parasitic nematode Anisakis, which can be used as a biological tag for hake Merluccius merluccius stocks throughout their geographical range, is reported. Hake were collected from 14 localities in the Mediterranean Sea and the Atlantic Ocean. Anisakis larvae (n = 1950), which were recovered, were identified to species by means of genetic markers (allozymes). Within Anisakis type I, the larvae of A. pegreffii, A. simplex s.s., A. typica and A. ziphidarum were detected, while within Anisakis type II, A. physeteris, A. brevispiculata and Anisakis sp. were identified. There were significant differences in the relative proportions of the various Anisakis species identified in hake samples from the Mediterranean Sea and Atlantic Ocean, suggesting the existence of different stocks of M. merluccius in European waters.