Lithophaga lithophaga

The date shell, or date mussel (*Lithophaga lithophaga*), is a bivalve mollusk in the family Mytilidae. Its name comes from Greek words meaning “stone” and “eating,” a reference to its habit of boring into marine rock. The burrows it creates are called Gastrochaenolites.

Fossils of this species appear in marine strata from the Miocene through the Quaternary, spanning roughly 16 million years ago to the present. Today, it is found in the northeast Atlantic Ocean, the Mediterranean Sea, and the Red Sea. Along the Adriatic coasts of Croatia and Montenegro, it is known locally as *prstaci*.

These bivalves live mainly in wave-battered zones but can also be found at depths of 125 to 200 meters. They grow very slowly: reaching 5 centimeters in length takes 15 to 35 years. Adults feed by filtering plankton, algae, and debris from the water. Sexual maturity is reached after about two years, and a single female can release between 120,000 and 4.5 million eggs per season. Fertilization occurs in open water.

The shell itself reaches about 8.5 centimeters in length. It is yellowish or brownish, nearly cylindrical, and rounded at both ends. The interior is whitish, iridescent purple, with a pink tinge. The shell is relatively thin, and its surface is nearly smooth but covered with growth lines that can sometimes be quite rough.

In Mediterranean cuisine, date shells are considered a delicacy, often cooked and served in a broth of white wine, garlic, and parsley. However, extracting them requires dismantling the rocks they inhabit, which can lead to coastal desertification. As a result, several countries—including Croatia, Italy, Slovenia, France, Greece, Montenegro, and others party to the Bern Convention—have restricted or banned their collection. The species is listed in Appendix II of CITES, meaning international trade is regulated by permit. As of 2004, the population along the Turkish coastline was not considered threatened.