Parasite–copepod interactions in Svalbard: diversity, host specificity, and seasonal patterns

Abstract Copepods of the genera Calanus and Pseudocalanus are important components Arctic marine ecosystems. Despite key roles these zooplankters, little is known about organisms they interact with most intimately, their parasites symbionts. We applied metabarcode sequencing to uncover eukaryotic present within two copepod from three areas around high archipelago Svalbard. Ten distinct parasite groups were observed: four different Apostome ciliates, dinoflagellates ( Chytriodinium sp., Ellobiopsis Thalassomyces Hematodinium sp.), a Paradinium trematode. ciliates closely related Pseudocollinia spp. commonly observed parasite, overall infection rates 21.5% in 12.5% . Infection by varied seasonally, no infections early winter, but exceeding 75% spring. Host specificity between parasites, significant differences rate host for (two , trematode). The diverse assemblage copepods, frequency infection, over one five individuals infected, suggest may be playing greater role plankton communities than generally acknowledged.