Several mild riblets at anterior, causing a crenulate anterior margin. Ventral margin slightly concave. No hinge teeth. The byssus is well developed, forming an attachment to the substratum. It may build important colonies and produces dense mats by stabilising soft substrata.
Sexes are separate.
Spawning time varies within a limited spawning season. Lives in protected areas such as lagoons or estuaries subtidally to 20m. Well established in lagoons of the western Mediterranean, uncommon in the far eastern Mediterranean. In the Pacific coast of America the dramatic increase of the mussel's population is presumably due to tranfer in the ballast waters of ships. The Egyptian and Israeli records, if not accidentally transported, are lessepsian migrants of the Red Sea species locally called Arcuatula arcuatula .