Anisakis simplex (Rud., 1809) (Nematoda: Anisakidae): growth and morphometry of larvae from spring spawning herring (Clupea harengus membras L.) in the Vistula lagoon and adjacent areas of the Baltic Sea
Third-stage A. simplex larvae are described infesting baltic herring in the Vistula Lagoon and adjacent areas of the Baltic Sea (ICES-subdivisions 26). Morphometric measurements and peculiarities of allometric growth of A. simplex larvae are similar to those found as larvae of fishes in other regions, range size was wider. Growth of A. simplex larvae during spawning migration of their hosts was noted. High infestation (up to 375 specimens per fish) and the wide size range of larvae (8.0-30.0 mm) confirms that the third-stage A. simplex larvae stay alive in their hosts and increase over time.