Parasites of resident arctic charr, Salvelinus alpinus, and brown trout, Salmo trutta, in two lakes in Iceland

Arctic charr and brown trout in two dissimilar lakes in Iceland were examined for parasites, altogether 40 fish, 10 of each species in each lake. At least 22 parasite species were found; Protozoa: Spironucleus salmonis, Apiosoma sp., Capriniana piscium, Trichodina sp., Dermocystidium branchiale; Myxozoa: Chloromyxum truttae, Myxidium truttae, Myxobolus arcticus, M. cerebralis, M. neurobius, Sphaerospora truttae; Helminths: Apatemon gracilis, Diplostomum sp., Crepidostomum farionis, Phyllodistomum conostomum, Diphyllobothrium sp., Eubothrium crassum, E. salvelini, Philonema oncorhynchi, Capillaria salvelini; Crustacea: Salmincola edwardsii and Salmincola (salmonea) sp. Six of the observed species are new records in Icelandic freshwater fish. In general, the total parasite fauna of the two lakes showed a high degree of similarity, both with regards to micro- and macro-parasites. The majority of species were found in both lakes and many in/on both fish species. However, a considerable variability in prevalence and intensity between lakes and/or fish species was evident for certain parasite species. The results of the present study are compared with other similar studies in Iceland as well with the occurrence of the parasite species in neighbouring countries