June 26, 2026 — A longstanding federal definition of “shellfish” is changing to better reflect modern biology and simplify seafood trade regulations.
According to Newsweek, the U.S. Fish and Wildlife Service (USFWS) finalized a rule on June 23 that removes the requirement that shellfish have an external shell. The updated definition takes effect on July 23, 2026
Under the revised rule, shellfish now includes aquatic invertebrates within the phylum Mollusca, bringing squid, octopus, cuttlefish and other cephalopods under the same regulatory definition as oysters and clams. Crustaceans such as lobster, shrimp and crab remain included.
The previous definition described shellfish as “any species of mollusk having a shell,” language that regulators said no longer matched current biological classifications. Because many cephalopods have internal, reduced or no external shells, the old definition created uncertainty in how these species were handled at U.S. ports of entry.
Read the full article at the National Fisherman