Internal helminth fauna of Baltic herring, Clupea harengus membras L. (Clupeiformes) from southern Baltic

In the years 1994-1996, a total of 592 specimens of her ring Clupea harengus membras L., caught in southern Baltic, were examined. The investigations revealed four species of trematodes: Hemiurus luhei, H raabei, H levinseni, Brachy phallus crenatus, two species of nematodes: Hysterothyla cium auctum (syn. H aduncum), and Anisakis simplex and three acanthocephalans: Echinorhynchus gadi, Metechino rhynchus salmonis and Pomphorhynchus sp. The finding of H levinseni constitutes the first record of this species in Pol ish waters. The infection parameters of hen-ing (prevalence, intensity and abundance) were compared in relation to differ ent capture areas and seasons of the year. Possible affects of the feeding ground, fish body length and the spawning group of herring on the infection levels were also examined. No reiation was observed between the place and the sea son of catch and the infection level of herring. The fish repre senting different feeding grounds (Baltic, Danish Straits) and sequential length classes showed variable parameters of in fection.