The U.S. Fish and Wildlife Service (FWS) has updated the regulatory definition of “shellfish,” removing the long-standing requirement that species must have an external shell. The rule, published on June 23 in the Federal Register, updates the Code of Federal Regulations to better align with current scientific understanding and industry standards. As a result, cephalopods such as squid, cuttlefish, and octopus are now included under the shellfish category.

Updated Definition and Implications

Previously, federal regulations defined shellfish as any mollusk with a shell. This definition excluded cephalopods, leading to regulatory confusion. The revised definition now covers aquatic invertebrates within the phylum Mollusca. This includes oysters, clams, squid, and octopus, as well as crustaceans like lobster, shrimp, and crab. Removing the “having a shell” phrase acknowledges cephalopods, which often have internal or reduced shells.

Impact on Trade and Regulation

The previous shellfish definition caused inconsistencies in how cephalopod shipments were treated. This change addresses concerns from industry groups who have advocated for clarity in classification. In October 2025, the U.S. Small Business Administration’s Office of Advocacy highlighted the regulatory and financial complications faced by squid harvesters due to the ambiguity. Squid exporters and importers faced numerous fees, including a $93 inspection fee and $100 licensing costs. Small businesses found these fees burdensome.

The Mid-Atlantic Fishery Management Council had requested this change, emphasizing the redundant inspection requirements squid producers faced. Unlike most U.S. commercial fishery products, which are exempt from such regulations, squid were under extensive licensing demands meant to prevent unauthorized wildlife trade.

Considerations for Allergies

While the regulatory definition change is not medical, it references cephalopods’ existing treatment in clinical allergy contexts. Cephalopods, such as squid and octopus, are often linked to shellfish allergies in medical literature despite lacking external shells. This update does not change allergy risks but clarifies their classification, helping eliminate confusion in labeling and trade terms.

Contact Newsweek editors: Matthew Cannon and Tony Phillips