Parasite fauna of landlocked Dolly Varden (Salvelinus, Salmonidae) from the river–lake system of Uzon caldera (Kamchatka)

Parasitological research of two landlocked populations of Dolly Varden (Salvelinus malma) dwelling the river–lake system in the Uzon caldera (Kamchatka) was done for the first time. Twelve species of fresh-water parasites were found. Charrs from the Lake Tsentral’noe–Shumnaya River were infected by Eubothrium salvelini, Diphyllobothrium ditremum, D. dendriticum, Crepidostomum farionis, Cr. metoecus, Ichthyocotylurus erraticus, Sterliadochona ephemeridarum, Philonema oncorhynchi, and Cucullanus truttae. Charrs from the Lake Dal’nee were infected by Henneguya zschokkei, Chloromyxum coregoni, Proteocephalus longicollis, and Cucullanus truttae. Based on stomachs content and parasites abundance, it was found that charrs from the Lake Dal’nee feed on plankton, and at length more than 12 cm, switch to cannibalism. In the contrast, charrs from the Lake Tsentral’noe and Shumnaya River primarily feed on benthos and rarely on plankton, and no cannibalistic specimens were found.