Clams with a tightly closed shell are alive and can be safely eaten. According to the U.S. Food and Drug Administration, tapping the shell of an open clam that is alive causes the shell to immediately close. Clams that remain open after the shell is tapped are dead or dying and should not be eaten. Cracked or broken shells also indicate the clam is dead.Know More
Clams belong to the animal group called bivalves. This group also includes mussels, oysters and scallops. The soft body parts of these shellfish are enclosed between two shells. Bivalves are closely related to abalone, snails, slugs, squid and octopuses. These animals, including bivalves, are collectively called mollusks.
There are freshwater and marine clams ranging in size from microscopic to giant species that weigh as much as 440 pounds. Clam life cycles range from one year to hundreds of years. All clams are filter feeders that strain food particles from the water. Other animals that use this method of feeding are krill, sponges and baleen whales. Clams are a common food item, although not all species are considered palatable.
Commonly harvested hardshell clams include Manilla and Native Littlenecks, Butter Clams and Macomas. These clams are found on beaches of mixed sand or gravel and mud. They are commonly harvested using shovels or rakes. Except for the large Butter Clams, rakes are most effective and less damaging to the clams and the beach.Learn more about Marine Life
The angelwing clam, Cyrtopleura costata, is a large clam that can be found from Massachusetts to the Carolinas, down through the Caribbean and to the coast of Brazil. It gets its name because the shape of its fragile shells are reminiscent of the wings of angels.Full Answer >
Seashells, which are the exoskeletons of mollusks such as snails, clams and oysters, form from the bottom up starting with mantle tissue located underneath and in contact with the shell. The mantle secretes proteins and minerals to form layers. Mollusk shells have three separate layers: the uncalcified outer layer called the proteinaceous periosteum, a calcified prismatic layer and a calcified inner layer called nacre.Full Answer >
The oldest portion of a clam's shell is called the beak or umbo. Clams grow their shells around themselves, continually adding new material in concentric rings, starting at the beak and moving outward.Full Answer >
The mantle of a clam is within the interior of the shell. It lines the underside of both shell valves and contains the animal's internal organs. The outside surface of the mantle is made up of mantle lobes, and the interior is called the mantle cavity.Full Answer >