Shellfish are animals with shells that live in the water. They have no backbone and are popular to eat. Fisherman need to identify shellfish in order to avoid those that may be poisonous while many people allergic to shellfish need to identify which type to avoid.
Know that there are two types of shellfish-crustaceans and mollusks. Crustaceans have segmented bodies with crust-like shells. Mollusks have shells encasing their soft bodies.
Identify crustaceans by their sometimes unsymmetrical, elongated bodies and their eyes on stalks. Examples of crustaceans are shrimp, crabs and lobsters. Find mollusks by their shells which are closed or partially covering their soft bodies. Oysters, scallops, mussels and clams are examples of mollusks.
Locate many types of clams on both the Atlantic and Pacific coasts of the U.S. Hard clams have a grayish white shell on the outside which is white on the inside with a purple spot in back. Their meat is orange and can also be used in place of oysters in recipes.
Notice mussels by their smooth, long blue-black shell. They can be found throughout the world and their meat is either orange or white. Catch oysters from the Atlantic coast of the U.S. to the Gulf of Mexico. They have rough, irregularly-shaped shells and their meat is usually cream, tan or gray.
Associate scallops with their beautiful fan-shaped shells. The different types are found mainly throughout the Atlantic Ocean. Their meat is white or orange and toughens when overcooked.
Realize that shrimp are also called prawns, and many types found in the oceans of North America. They're usually brown, white or pink. Note that there are several types of crabs found in North America. The blue crabs in the Atlantic, king crabs in Alaska and Dungeness crabs in the Pacific all have delicious white meat.
See that lobsters look similar to crabs but are larger. They have dark shells that turn bright red when cooked and two claws with pincers. Lobsters are found in Atlantic waters and are best when cooked live in boiling water.