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Hermit Crabs vs. Crabs (The Key Similarities and Differences)

Hermit Crabs vs. Crabs (The Key Similarities and Differences)

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This post is written to the author's best knowledge and is not intended to be used in place of veterinary advice. In addition, this post may contain affiliate links. As an Amazon Associate I earn from qualifying purchases.

Hermit crabs are starting to become fairly common pets. They’re fun pets to own that don’t take up a lot of space.

If you’ve been looking into hermit crabs recently, you might be trying to learn a bit about them. When you don’t know much about them, you might wind up thinking that they’re similar to most other types of crabs.

What are the differences between hermit crabs and other types of crabs? Is there something that makes hermit crabs stand out?

Continue reading to learn about what makes hermit crabs special. You’ll get basic information about both hermit crabs and crabs.

Hermit Crabs and Crabs Are Much Different

Below, you’ll learn about things that make hermit crabs and standard crabs much different. There are so many differences to consider.

Once you’ve read about all of the differences, it should be easier to understand why hermit crabs are unique. It’ll also give you a better picture of what hermit crabs are truly like if you don’t know a ton about them yet.

Hermit Crabs Breathe Differently

One of the first things to take into account is that hermit crabs don’t have lungs. These crabs possess gills.

There are marine hermit crabs that spend their lives underwater. You’ll also find land hermit crabs that possess modified gills.

These hermit crabs live on land, but they need to keep their gills moist to be able to breathe. They live in humid environments and they store water in their shells to keep their gills hydrated.

Hermit crabs are pretty unique in this regard. It’s interesting how land hermit crabs have adapted to be able to live on land.

They Have Body Differences

When looking at hermit crabs and standard crabs, you’ll see that they have body differences. Hermit crabs have hard exoskeletons, but near the abdomen things are much softer.

This has caused hermit crabs to adapt by protecting themselves with shells. They utilize the shells of other organisms such as mollusks.

Normal crabs have very tough exoskeletons that keep them safe from predators. They don’t need to use other shells to protect themselves.

The shell aspect of hermit crabs will be one of the most unique things about them. Many people find the fact that hermit crabs use shells to be quite charming.

The Legs Are a Bit Different

The legs are a bit different as well. When you compare hermit crabs and standard crabs, you’ll see that they each possess five pairs of legs.

You’ll find that the difference comes into play when you look at how the crabs use their legs. Hermit crabs have one pair of legs that forms the pincers with the right side being larger than the other.

The hermit crab uses the second and third pair of legs for walking. Its fourth and fifth pairs of legs are shorter and are specifically used to grip its shell.

Crabs have five pairs of legs, too, but four pairs are used for walking. The front pair of legs is used to protect the crab with the pincers.

Differences with the Eyes

Differences with the eyes are apparent when looking at each type of crab. Hermit crabs have large eyes that are capable of seeing things very well.

Their compound eyes give them a 360-degree view. This allows them to detect motion easily and it makes it easy for them to see at night.

Normal crabs are different because they possess one pair of primary compound eyes that are on top of eye stalks. They also possess other eyes on top of their shells, but those are more primitive.

They can use these eyes for UV light detection as well as moonlight. The lunar cycle is involved in crab mating.

Different Habitats

Hermit crabs have different habitats than standard crabs. Marine hermit crabs live in saltwater and land hermit crabs live near beaches where they’ll have access to both sand and water.

Since hermit crabs need water to keep their gills wet, they don’t usually live too far from beaches. Other crabs might live in many different environments.

You can find different types of crabs living in coastal reefs, rivers, streams, and even in the high or low tides of the sea. It’s easy to spot some types of crabs living on land, climbing trees, and even digging in the sand.

Both Are Omnivores

Both hermit crabs and standard crabs are omnivorous creatures. In the wild, hermit crabs often eat tiny clams, mussels, algae, and even bits of dead animals.

Standard crabs will eat pretty much anything that they can find. They usually eat things such as algae, fungi, bacteria, worms, and other crustaceans.

Different Lifespans

Hermit crabs have the potential to live much longer than standard crabs. Some hermit crabs are known to live for decades.

There are hermit crabs out there that can live for up to thirty years. In the wild, hermit crabs can survive for quite some time.

Standard crabs have lifespans that vary, but they can also live a fairly long time. Some grabs will only live for two or three years, but others might live for as long as twelve years.

Both Types of Crabs Molt

Both types of crabs go through a process known as molting. Molting is something that hermit crabs do several times as they continue to age.

They shed their existing exoskeleton and grow a new one. Hermit crabs are known to bury themselves in sand during the molting process, and you shouldn’t disturb them during this time or they might die.

Standard crabs also molt, and this happens many times in a young crab’s life. The old shell starts to soften and will eventually erode.

The crab must extricate itself from the old shell and this usually takes hours. The new shell will be soft in the beginning, but it’ll harden over time.

Final Thoughts

Now you know the basic differences between hermit crabs and standard crabs. They do have similarities, but they’re also very different.

The biggest difference involves hermit crabs utilizing the shells of other creatures such as mollusks. It’s also more common for people to keep hermit crabs as pets.

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