Philometra sanguinea is a nematode which as an adult, infects the fin rays of Goldfish (Carassius auratus and Crucian Carp Carassius carassius) .This parasite is native to Eurasia. It was observed in Goldfish imported from Japan. This parasite is likely to occur in captive and wild populations of goldfish in North America, but the only record of which we are aware is at the Tracy fish screening facility, in the Sacramento-San Joaquin Delta in 1973, from the fins of Goldfish.