Mottled, unattractive shell Gray splotches on inside surface
Even without pearls, our Oyster is worth many thousands of dollars a year to shellfish dealers because of its delicious flesh. Its tropical relatives are the pearl producers.
Mussels (Mytilidae)
Blue-colored shells Shells covered with black, horny skin
Living mussels are always found attached to rocks or pieces of wood by tiny threads of their own making. Two common mussels are:
Edible Mussel (Mytilus edulis): Smooth, velvety-blue shell identifies it. The animal within is edible and quite delicious. It is commonly utilized as food in Europe but less so here, where we have, and seem to prefer, the Oyster.
Ribbed Mussel (Modiolus demissus plicatulus): Similar to the above but with many distinct ribs radiating on the surface. The Ribbed Mussel is not considered edible. While not poisonous, it is most unpalatable.
Hardshell Clam (Venus mercenaria)
Thick, round shell Purple blotches on inside surface