Shells of the Unequal Spoonclam, Periploma margaritaceum, showing their valves of different shapes and sizes. The right valve is larger and more concave than the left. (the black background shows a 5mm-grid).

The University Beach is only about a 10 minutes walk from my office, so I conduct short weekly visits to the beach in particular to study this little clam. (Therefore, here are some photos taken at different dates).

The species is prey to the gastropods known as Moon Snails (several species), which drill a narrow borehole 1-2 mm in diameter. Since the bivalve buries a shallow depth into the sediment, usually lying on its side with the right valve on top, boreholes on the right valve can be more common, but occur on both valves.

See more about this species at the Biodiversity of the Gulf of Mexico (BioGoMx) database at:
http://gulfbase.org/biogomx/biospecies.php?species=Spp-35-0496