Lamprey

Lamprey (Lampetra fluviatilis, the river lamprey; sea lamprey Petromyzon marinus is also eaten) is a primitive jawless fish of minor commercial importance, found in European coastal waters, rivers and lakes. Since its skin mucus and blood serum contain toxic proteins, the flesh must be washed and bled thoroughly before cooking; fresh and smoked lamprey are usually eaten fried, grilled or in traditional pies (notably in Finland and Portugal). Careful preparation — thorough washing, removal of slime, complete cooking — removes the toxins and makes this traditional food safe; as a fatty fish it also needs prompt chilling to prevent spoilage.