Crab Classification: Are Crabs Mammals?

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Crabs can be found all over the world in many oceans, freshwaters, estuaries, streams, and even on land.

With over 4500 species in total, these animals can be found all over the place and are a popular dish for many of us Americans.

In this post, we’re going to take a look at what family crabs belong to, and specifically answer are crabs mammals?

In a nutshell, no, crabs are not mammals. They have no mammary gland and are not warm-blooded, meaning they are not related to mammals.

What Is A Mammal?

By definition, mammals are a group of vertebrates constituting the class Mammalia, characterized by the presence of mammary glands which in females produce milk for feeding their young, a neocortex, fur or hair, and three middle ear bones.

Seals, whales, sea otters, dugongs, and polar bears are all marine mammals. This means they are aquatic mammals that rely on the ocean and other marine ecosystems for their existence.

Although crabs typically rely on the ocean, they do not have a mammary gland and therefore are not mammals.

What Are Crabs Classified As?

Crabs are categorized as decapod crustaceans, they have a short tails and are covered with a thick shell or exoskeleton that offers protection.

They are arthropods, which have over 1 million different species under their umbrella group on earth. More than any other phylum.

Over 90% of arthropods are insects, but in this article, we are focused on specifically marine arthropods.

Some examples of marine arthropods include crabs, lobsters, and shrimp. The most obvious characteristic of arthropods is an exoskeleton, which is different from a shell.

Not only does this exoskeleton protect them from predators, but it also works just like how human skin works.

Crabs are also armed with a pair of claws that are used to defend themselves as well as grip food or prey, making it easier for them to eat.

Crabs are invertebrates, which are animals without a backbone. They have five pairs of legs and are also omnivores which means they eat a variety of food both of plant and animal origin.

Are Crabs Fish Or Not?

Despite some crustaceans such as crabs and lobsters sometimes being referred to as “shellfish”, they are actually not fish at all.

However, crabs can are quite similar to fish in that they have gills, and some species even have lungs that allow them to survive on land.

Crabs will require their gills to be moist in order to survive on land, they reproduce via eggs and sperm too, just like fish.

But, when it comes to categorizing these animals, they are crustaceans, and certainly NOT fish.

Final Thoughts

Hopefully, you now have a clear answer to are crabs mammals. No, they are not. They are crustaceans that fit into the arthropod family alongside others such as lobster and shrimp.

Crabs do not have mammary glands or produce milk for their young, nor do they have hair or any other characteristics that mammals have.

They are similar to fish in the sense that they have gills and are sometimes categorized as shellfish, but ultimately they are not fish.

I really hope you have enjoyed this post and have learned something new today about crabs as a species.

Thanks for taking the time to read this post and feel free to stick around to learn more about the wonderful world of crabs.