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Is Octopus A Shellfish?

Shellfish are sea creatures that, for the most part, have a noticeable shell or at least a shell-like exterior. Some kinds of shellfish, like lobsters, shrimp and crab, are considered a delicacy in different parts of the world and are coveted for their sumptuous taste.

Shellfish are also rich in protein, healthy fats and other nutrients that can improve heart, brain and immune health.

Is octopus a shellfish? Yes, octopus is among the wide spectrum of marine animals belonging to the shellfish family. These creatures range from lobsters and crabs to crayfish, shrimp, sea urchin, octopus, squid, oysters and more.

Shellfish come in all shapes and sizes and are mostly found in seawater, although there are some that live in fresh water sources.

Not all shellfish are sought after for food, nor are they all healthy to eat. Sadly, some shellfish contain contaminants like mercury, lead and industrial chemicals due to the polluted state of many of our oceans and seas.

Other shellfish contain allergens that can trigger serious allergic reactions in people who are sensitive to these substances.

Is Octopus A Shellfish?

To differentiate between the different types of shellfish, marine biologists have divided these creatures into two categories: crustaceans and mollusks. Crab, shrimp, crayfish and lobster are common examples of crustaceans.

Mollusks consist of marine animals from three subgroups: the gastropods (snails and slugs), the bivalves (mussels, clams, scallops, oysters) and the cephalopods. It is under the latter subgroup that we find the octopus.

So, yes, octopus is considered a shellfish under the mollusk category within the subgroup of cephalopods.

The octopus is an amazing creature characterized by a rotund body, dark, protruding eyes and eight long, dexterous arms that can act independently from its brain. If an arm should be cut off by a predator, the octopus will simply grow a new one to take its place.

There are over 200 species of octopuses in existence today, with more being discovered all the time. Most of these reside in deep sea waters, which is why the octopus is often referred to as the “monster of the deep.”

The majority of octopuses are predatory creatures and all have venom which is used to kill their prey. The giant Pacific octopus, with a weight of around 33 pounds and an arm span of up to 14 feet, is the largest known species. The red octopus, growing less than 24 inches, is considered one of the smallest.

Why Is The Octopus Considered A Shellfish?

By name alone, you would think that all shellfish would have a shell or some kind of hard exterior covering that acts like a shell.

According to marine biology research, octopuses and squids did sport a hard shell in ancient times. Apparently, this shell dissipated over the years through the process of evolution, transforming our modern octopus into the squishy creature that it is today.

Despite not having a hard exterior shell, the octopus is still considered a mollusk and a member of the cephalopod clan, which is part of the shellfish family.

The octopus shares the same body structure of all cephalopods, i.e. a head, body and foot, a muscular “casing” or mantle that protects its internal organs and “arms” attached to its head.

Like many other cephalopods, the octopus has three hearts, blue blood and a high level of intelligence, which makes this creature capable of procuring, processing and applying information for self-defense and preservation.

Octopuses dwell in sea water and inhabit every ocean on the planet, generally abiding in coastal waters. They’re mostly solitary creatures, spending a great deal of time holed up in dens, rock crevices or coral when not hunting for food.

When in danger, the octopus may change colors to camouflage itself or eject ink at a predator as a smoke screen so he can make his great escape.

Can I Eat Octopus If I Have A Shellfish Allergy?

Although octopus is an edible shellfish, that doesn’t mean cooked octopus is safe to eat for everyone. People with fish or shellfish allergies should be very careful of the seafood they eat as it could trigger a harmful allergic reaction.

Fish allergies are not the same as shellfish allergies. You may be able to eat fish safely and not tolerate octopus due to having a shellfish allergy.

Shellfish are not the same as fish – they’re a totally distinct type of marine life that may contain hazardous allergens for people who have a shellfish allergy.

People with shellfish allergies are more susceptible to having allergic reactions from eating octopus and other shellfish products.

Your allergy symptoms may range from wheezing and shortness of breath to chest pain, dizziness, nausea, vomiting, swelling of tongue, throat or eyes or developing hives. A shellfish allergy can even lead to anaphylaxis – a severe reaction that can cause your body to go into shock.

For safety’s sake, it’s best to avoid all types of shellfish and foods containing shellfish ingredients if you have a shellfish allergy.

This includes octopus, lobster, clams, oysters, shrimp and other crustaceans and mollusks. The octopus is but one of many kinds of shellfish that pose a risk of allergic reactions to people with shellfish allergies.

Can I Handle My Pet Octopus If I Have A Shellfish Allergy?

Although it’s more common to suffer an allergic reaction from consuming octopus, touching an octopus could also trigger a negative response if you have a shellfish allergy.

If you’re sensitive to shellfish, eating, touching or even inhaling the vapors of cooking shellfish can put you at risk of an allergic attack.

Shellfish allergies can be unpredictable in that some kinds of shellfish may affect your system while others may not. Some shellfish may trigger severe reactions, while others only cause a mild response.

You may have consumed shellfish for years with no negative effects and then one day, you start to experience allergic reactions.

Although anyone is susceptible to developing shellfish allergies, they’re more common in adults. However, children are not immune to this problem.

Before getting an octopus for a pet, it’s a good idea to count the cost. Octopuses can be demanding creatures, requiring quite a bit of care. It’s also quite an investment to set up the right environment and keep your octopus fed.

If you have a shellfish allergy, you’ll have to be extra careful when caring for your pet to prevent allergic reactions.

Why Can Octopus Trigger A Shellfish Allergy?

When you’re allergic to a particular substance in food, like proteins in octopus or other types of seafood, your body sees that substance as an “enemy” and creates antibodies to fight against it.

These antibodies stimulate your cells to produce chemicals against the allergens, which trigger symptoms of allergic reactions. The severity of your symptoms depends on your immune system’s response to the allergens.

The octopus is one of dozens of shellfish marine animals that contain proteins or other allergens that automatically trigger allergic reactions in people with shellfish allergies.

Your system may react within minutes of consuming cooked octopus or symptoms may start within an hour or two after finishing your meal. As no two people are exactly alike, it’s hard to predict whether your symptoms will be mild or severe.

In general, people tend to be more allergic to crustaceans than mollusks, with shrimp being the main culprit for triggering allergic reactions. That doesn’t mean you should let down your guard thinking you’re safe by consuming octopus as it is a mollusk.

Once you’ve developed a shellfish allergy, you’re likely to have it for life, making it that much more important to protect yourself against potential attacks by avoiding shellfish products.

This includes shellfish broths, sauces, soups and stews, shellfish meals in seafood restaurants as well as shellfish ingredients in packaged foods.


The good news is that shellfish allergies can be controlled by simply taking shellfish off of your menu altogether. Is octopus a shellfish? Yes. Should it be included in your shellfish ban? That would be the wisest decision, if you want to reduce your risk of suffering an allergic attack due to your shellfish allergy. Cooked octopus is, after all, an acquired taste and not an essential for life. If you currently have or plan to get an octopus as a pet, take precautions to avoid direct contact with your “octy” when cleaning its tank and handling its food to avoid allergic reactions.