The shape of the shell edge distinguishes the Mediterranean scallop (left) from the king scallop (right).

Pilgrim symbol and a garland of eyes

Externally, the Mediterranean scallop is only distinguishable from its close relative, the king scallop, by experts. The scallops in the Mediterranean are not quite as large as the king scallops of the Atlantic, which can grow to 15 centimeters. In addition, they are recognizable by the soft, curved lines of the edge of their shells, while the ribs of the Mediterranean scallop appear nearly rectangular and sharp in profile. Both scallop species can also be seen in the mollusk display at the MEERESMUSEUM and the king scallop can be seen in two aquariums at the OZEANEUM.

Both scallops received their German names (“pilgrim scallop” and “St. James scallop”) because of their particular roles during the Middle Ages, when they were used by pilgrims to identify themselves on their pilgrimage to Santiago de Compostella to visit the tomb of James, son of Zebedee. They later became symbols of all those on journeys of pilgrimage, who would attach shells to their clothing to identify themselves as pilgrims. In addition, the curved shells were used by pilgrims as simple drinking vessels. The typical impressions and representations of scallops are today found in many pilgrimage churches and baptismal fonts shaped like shells.

In addition to their historical religious significance, both mollusk species are also remarkable for their specific behaviors. The mollusks, which live in the bottom sediment, use a garland of clearly visible eyes to detect approaching predators, such as starfish. With pumping movements made by their shell halves and water stream this emits, they are then able to make their way to safety by taking meter-long leaps.