Parasites of fingerling herringClupea harengusL.: ecology and fine morphology

Abstract

AbstractThe parasite fauna of young-of-the-year herringClupea harengusL., off Gullmarsfjord and Brofjorden, west coast of Sweden, was studied between May and October for 4 years, from 1994 to 1997. Fifteen species of parasites were found: two Protozoa –Trichodina sp.andCeratomyxa auerbachi; one species of uncertain affinity –Ichthyophonus hoferi; two Monogenea –Gyrodactylus harengiandPseudanthocotyloides heterocotyle; five Digenea –Cryptocotyle linguametacercariae,Cercaria pythionikemetacercariae,Hemiurus luehei,Lecithaster confususandPseudobacciger harengulae; three Cestoda plerocercoids –Bothriocephalussp., an acrobothriid and a tetraphyllid; one Nematoda –Hysterothylacium aduncumlarva; and one Copepoda –Caligus elongatus. The number of species found in this study represents more than one-sixth of all parasites reported in herring worldwide and all parasites were acquired locally. The parasite fauna of herring from the west coast of Sweden is compared with that of herring from the Baltic Sea and other areas of the north-east Atlantic. The prevalence and intensity of parasites are presented and discussed. Morphological descriptions are based on both light and scanning electron microscopy and new features are described. Possible applications of this new information about the parasite fauna, in different areas of fisheries and fish biology studies, are discussed.