PARASITE LOADS OF RAFTED BLUE MUSSELS (MYTILUS-GALLOPROVINCIALIS) IN SPAIN WITH SPECIAL REFERENCE TO THE COPEPOD, MYTILICOLA-INTESTINALIS

A histopathological survey between late 1987 and 1989 at two locations and two depths of experimentally cultured blue mussels (Mytilus gallo provincialis Lmk.) in the Ria de Vigo (NW Spain) is presented. During this time, no mortalities were detected. The most frequent parasites a re Chlamydia-like organisms (CLO) and a Ciliophora-like organism (CILO ) in the diverticuli of the digestive gland, Mytilicola intestinalis i n the intestine, and Steinhausia mytilovum in oocytes and ciliates in the gills. The prevalence of the copepod M. intestinalis was influence d by the location and not by the depth of culture or origin of the mus sels. The trematode Proctoeces maculatus has a very low prevalence but causes severe lesions.