Silken Scallop Shell, Pecten sericeus: The Silken Scallop Shell is a somewhat unusual bi-valve since the right valve is moderately arched and the left valve is flat or nearly so.
They have 22 or 23 low and broad ribs that are triangular in section. The valves are brightly colored in shades of brown to pinkish with the left valve being more highly colored than the right.
They range in size to 7.5 cm (3.0 inches). They are found in sand offshore at depths up to 500 feet in the lower two-thirds of the Sea of Cortez and south to Peru.
These shells are “uncommon” and currently sought after for use to make decorative jewelry. They are also sold for shell collections via a brisk internet trade.
The Silken Scallop Shell is a large sized member of the Pectinidae Family which are more commonly known as the Scallop Shells. The shells are highly colored, nearly circular with wing like extensions on the hinge line with radial exteriors and porceleaneous interiors. There are numerous members of the family which are found in both warm waters and cold waters. Most are free swimming. They have long been a favorite of shell collectors due to their simple beauty of form. Five members of the family are found in Mexican waters. However none are commercially important.