The parasitic turbellarian Urastoma cyprinae (Platyhelminthes: Urastomidae) from blue mussel Mytilus galloprovincialis in Spain: occurrence and pathology

Abstract

The turbellarian Urastoma cyprinae (Graff. 1882) Graff. 1903 was found inhabiting the mantle cavity between the lamellae of the demlbranchs of mussels Mytilus galloprovincialis Lamarck cultured in Galicia (NW Spain). Heavily infested mussels were recognized by the presence of white spots in the gills. The affected area exhibited disarrangement of the gill filaments. The space between 2 lamellae was considerably reduced and the blood sinuses were wider in the unhealthy area than in the healthy area. The turbellarian also induced a heavy lnflltration by blood cells and subsequent necrosis of the gill tissues. Routine parasitolog.ica1 stud~es showed that this parasite was first detected in the Galician region in early 1989. In 1993, U. cyprinae appeared to be present in the 3 main production rias in the Galician region, affecting both natural beds and rafted mussels. U. cyprinae could be considered a potential threat to mussel culture.