also known as: gill fluke
Dactylogyrus species are monogenetic trematodes (i.e. have direct, 1-host life cycles). They are parasites that can be found on the gills, occasionally skin and fins, of freshwater fish. Their have a mouth and eyespots on their anterior (head) end and anchoring hooks on their posterior. They have direct fish-to-fish life cycles. Adults lay 4-10 eggs per day, which then take 4-5 days to develop and hatch. They are not usually found on salmonids, but are common on many of the introduced warmwater fish in Oregon, including crappie and bass, and can be problemmatic in home aquaria.