石川県で採集されたイワナの寄生虫，ミヤマナガクビムシSalmincola markewitschi

抄録

The lernaeopodid copepod Salmincola markewitschi Shedko and Shedko, 2002 was collected in July 2019 from the buccal cavity of whitespotted char, Salvelinus leucomaenis (Pallas, 1814) (Salmonidae), reared at the Ishikawa Prefecture Fisheries Research Center (36°15′11″N, 136°25′17″E) in Kaga, Ishikawa Prefecture, central Japan. This represents the first record of Salmincola markewitschi from Ishikawa Prefecture. All of the four whitespotted char examined (263–324 mm standard length) were infected each by 2–5 adult females of Salmincola markewitschi. The adult female of copepod is described. The species is considered to have been introduced along with infected whitespotted char transported alive from a commercial trout farm in the same prefecture into the research center in January 2019. However, no infection was found after September 2019, which was caused by manual removal of copepods in July 2019 and their possible mortality due to unusually high water temperatures (up to 23℃) in August 2019. Since Salmincola markewitschi is morphologically similar to copepods previously reported as “Salmincola carpionis (Krøyer, 1837)” from salmonids (mainly chars Salvelinus spp.) from various localities of Japan, it is desirable to reidentify those copepods.