What Is Considered Shellfish?

Seafood is one of the most delicious and highly sought-after cuisines in the world today! With so many different dishes, types of fish, and ways to cook them, the possibilities with this style of food seem to be endless. Not everyone is going to be able to have every kind of seafood, as shellfish is one of the most common allergies out there. If this is an allergy that you or an acquaintance has, it’s important to be able to discern the difference between shellfish and other types of seafood. We show you how you can tell the difference for certain below!

The Definition of Shellfish

Knowing how to tell what seafood you can and cannot eat first means understanding exactly what shellfish are. On the surface, the definition should appear pretty easy – it sounds like it refers to all types of seafood with shells! However, this isn’t entirely true. While all undersea life with shells is referred to as shellfish, not all shellfish have distinct shells. These types of seafood can also have a shell-like exterior. So, while they don’t have traditional shells, they are still considered shellfish – and they could cause an allergic reaction!

Types of Shellfish

Shellfish are broken up into two distinct categories. You could be allergic to one or both of these categories (or only one of them!), so it’s important to be able to distinguish between them. The two main categories of shellfish are:

  • Crustaceans: These types of seafood include lobsters, shrimp, and crabs. They are invertebrates with a hard shell, segmented bodies, and gills. They are found around the world and make up some of the most popular seafood dishes out there!
  • Mollusks: Mollusks encompass animals that are found both underwater and on land! In the case of seafood-based mollusks, these include clams, oysters, scallops, octopus, and squid. They have a highly structured nervous system and a radula used for feeding, which is why octopuses and squid fall into this category.


These are the main types of shellfish, so as long as you don’t have a meal with these animals involved, you’ll be safe!

When Does The Allergy Kick In?

If you have an allergy to shellfish, it’s important to recognize the severity of your allergy. Some people don’t develop symptoms unless they eat shellfish, while others can break out by just being around them! Depending on how severe your shellfish allergy is, you may want to consider other options for your dinner. If you can be around shellfish, however, you can still get an excellent seafood dining experience!

Seafood of All Types At Mare Oyster Bar

At Mare Oyster Bar, we want to ensure that you have the safest and most enjoyable dining experience possible. We’re always willing to accommodate any allergies that you may have, and we have plenty of options to satisfy anyone’s taste palette. If you’re in the mood for seafood or Italian cuisine delights, make a reservation with us in the North End to perfectly satisfy your cravings!