Shell of the Week: The Dwarf Surf Clam
Mulinia lateralis (Say, 1822) is a small white clam that may reach 18 mm (0.7 inch) in length. Surf clams belong to the family Mactridae, and one of the main features that distinguish them from other local bivalves is the presence of an internal ligament. The ligament is the brownish structure near the shell beak that, acting as a spring, helps keep the shell valves slightly ajar when the clam is relaxed. Dwarf Surf Clams have their beaks in a central position, and a ridge on the posterior region of the shell. Shells of this species have been found in large numbers by local collectors on Sanibel and Captiva during the 2018–19 Winter Season.
The Dwarf Surf Clam, Mulinia lateralis, from Sanibel. Photos by José H. Leal.