Southern quahog

Mercenaria campechiensis

Family Veneridae - quahogs

Bivalve (2 shells); shell ovate, very inflated, beak angles towards the anterior; color grayish white, sometimes with a brown skin (periostracum), interior white; many thick, concentric ribs that go all the way around the shell (in juveniles the ribs are wide spread with smooth shell between the ribs); edges of the inner margin are crenulate; the depression in front of the beaks (the lunule) is as wide as long in large shells; has a small z-shaped pallial sinus; impression behind the beaks (the escutcheon) is well developed with a ridge between the 2 shells.
Similar Species
Similar to the Texas quahog, but the Texas quahog concentric ridges are weaker, and become smoother towards the center of the shell and its lunule is longer than wide.
Nearshore Gulf, bays, higher salinities
Maximum Size
17 cm (6 3/4)
Other Common Names
Previous Scientific Names