The Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA) requires the identification of Crustacean shellfish, among other allergies. There’s often confusion about what species are considered a Crustacean shellfish.
Shellfish have two groups, crustaceans, and mollusks/bivalves. An allergy to crustaceans is more common, requiring identification by the FDA. FALCPA does not require the identification of mollusks and bivalves.
Common crustaceans requiring identification:
Common mollusks and bivalves where identification is not required:
Finned fish is another allergy that requires identification, but it’s not to be confused with crustacean shellfish. Go here for more information on the major allergies identified by the FDA.