Date Mussel

(Lithophaga lithophaga), a mollusk of the class Bivalvia. The elongated (up to 10 cm), cylindrical shell is rounded at both ends and covered with a thick, brown, horny layer—the periostracum. Along the rim of the mantle are glands that secrete an acidic secretion, by means of which the mussel bores passages in limestone rocks, where it lives. The date mussel inhabits the Mediterranean and Red seas and is found along the western coast of Africa. It is particularly numerous in coral reefs (up to 1,000 individuals per sq m). The mussel is used as food.