10 Facts About Scallops

You may have eaten a scallop, but do you know exactly what you were eating? You also may have found a brightly-colored scallop shell on the beach. Here you can learn more about this popular seafood - where scallops live, how big they get and how they feed and reproduce.


1. Scallops are animals. Although they may not look like it, scallops are animals. They are in the Phylum Mollusca, a group of animals that also includes snails, sea slugs, octopi, squid, clams, mussels and oysters.

2. Scallops are bivalves. Scallops are in the group of mollusks called the bivalves. These animals have two hinged shells that are formed of calcium carbonate.

3. Scallops can swim. Unlike other bivalves like mussels and clams, most scallops are free-swimming. They swim by clapping their shells quickly, which moves a jet of water past the shell hinge, propelling the scallop forward.

4. Scallops have easily-recognizable shells. When you think of the term "sea shell," a scallop might shell might instantly come to mind. Scallops have fan-shaped shells, often with ridges or ribs. At the bottom of the shell, there are two auricles, or "ears".

5. Scallops have eyes. Scallops have about 60 eyes that line its mantle. These eyes may be a brilliant blue color, and allow the scallop to detect light, dark and motion.

6. Scallops are filter feeders. Scallops eat by filtering small organisms out of the water. As water enters the scallop, mucus traps plankton in the water, and then cilia moves the food into the scallop's mouth.

7. Scallops are found all over the world. Scallops are found worldwide, and they may live from the intertidal zone to the deep sea.

8. Scallops may grow to 9 inches in size. Atlantic sea scallops can have very large shells - up to 9" in length. Bay scallops are smaller, growing to about 4 inches.

9. When you eat a scallop, you're eating the adductor muscle. Scallops swim by opening and closing their shells using their powerful adductor muscle. This muscle is the round, fleshy "scallop" that you eat. The adductor muscle varies in color from white to beige. The Atlantic sea scallop's adductor muscle may be 2 inches in diameter.

10. Scallops reproduce by spawning. Many scallops are hermaphrodites - they have both male and female sex organs. Others are only male or female. Scallops reproduce by spawning - releasing eggs and sperm into the water. Once an egg is fertilized, the young scallop is planktonic, and then settles to the sea floor, attaching to an object with byssal threads. Most scallop species lose this byssus and become free-swimming as they grow.