Hermit crabs are some of the most interesting creatures you can find. So many people are now caring for them as pets.
When you have a hermit crab as a pet, it gives you a great chance to observe it. You’ll learn a lot about hermit crabs simply by observing them.
Perhaps you want to know more about hermit crabs before buying one, though. Below, you’ll learn about some of the ways that hermit crabs have adapted to the environment.
Learning about hermit crab adaptations will give you a greater appreciation for them. You’ll understand just how unique and intriguing they are once you’ve read everything.
Land Hermit Crabs and Marine Hermit Crabs
The first thing you should know is that there are two basic categories of hermit crabs. There are land hermit crabs and marine hermit crabs.
Land hermit crabs have been able to adapt to live on land. You’ll learn a bit more about that later.
For now, you should know that there are also hermit crabs that live pretty much entirely in the water. These are the marine hermit crabs.
Marine hermit crabs can breathe underwater and they cannot survive on land for very long. Some people keep marine hermit crabs in fish tanks because they find them to be interesting.
There are several different types of marine hermit crabs. They can be quite a fun addition to an aquarium, but you do need to ensure that any other tank inhabitants are compatible with them before adding them to a community tank.
Land Hermit Crabs Have Modified Gills
Land hermit crabs have modified gills that allow them to breathe oxygen. These hermit crabs have adapted to be able to live on land.
Since they have gills, you might expect that land hermit crabs would be able to live both in the water and on land. However, this is not the case.
If you were to put a land hermit crab in a tank of water, it’d die fairly fast. Hermit crabs will drown if they’re submerged in water for too long.
They have modified gills that breathe oxygen. The gills no longer function as normal gills.
It’s interesting how the modified gills work to allow these hermit crabs to breathe oxygen. They have to stay moist so that the hermit crabs can breathe.
This means that hermit crabs need to stay in areas with high humidity levels. Also, they have to keep their gills moist by using water that they store in their shells.
If hermit crabs are exposed to temperatures that are too hot, they will start to dry out. A hermit crab’s gills can get dry when they aren’t in a humid environment, too.
Hermit crabs that don’t have proper access to water will also be in trouble. They can survive for a while with water that they store in their shells, but they will eventually run out.
Hermit Crabs and Shells
As you likely know, hermit crabs need shells to be able to survive. You see, hermit crabs are very vulnerable when outside of their shells.
They have soft spots where they can easily be killed by predators. Living inside of shells allows hermit crabs to make up for this weakness.
Hermit crabs do possess exoskeletons, but they aren’t all that durable. The shells provide hermit crabs with protection and they don’t leave their shells unless they truly have to.
The shells that hermit crabs utilize belong to other creatures. For example, it’s common for hermit crabs to use shells that have been left behind by sea snails.
There are species of hermit crabs that use other types of shells, too. A hermit crab will look for a shell that is the right size so that it can protect itself from threats.
As hermit crabs grow, they’ll need to find larger shells. Hermit crabs go through a process known as molting.
This is when a hermit crab sheds its exoskeleton and grows a larger one. It’s something hermit crabs will do many times over the years.
Once the hermit crab has grown, it’ll need to find a larger shell. It’ll go around and search for a shell that suits its needs.
Sometimes it’ll take the hermit crab a while to find a new shell. Land hermit crabs can be rather picky when looking for new shells.
You might see a pet hermit crab switch shells many times while it tries to find the perfect fit. This is why it’s imperative to have shells of many sizes in the habitat.
It’s easy enough to buy various shells from pet stores for the hermit crab tank. Having many shells of various sizes will ensure that the hermit crab has options to choose from.
Marine Hermit Crabs and Anemones
Marine hermit crabs are interesting in different ways than land hermit crabs. You may not know this, but marine hermit crabs are known to form symbiotic relationships with certain types of anemones.
They wind up helping each other out in various ways. An anemone is normally a creature that has limited mobility.
It can’t get around very well, but it can get around a lot easier by attaching itself to a hermit crab’s shell. Hermit crabs wind up liking having anemones along for the ride because they protect them.
An anemone will use its stinging capabilities to attack would-be predators. Anything that approaches the hermit crab to try to eat it will wind up getting stung and killed by the sea anemone.
Hermit crabs gain protection and it’s very valuable to them to have a sea anemone to rely on. A hermit crab wants to keep its sea anemone and would only abandon it in a desperate situation.
The sea anemone winds up benefiting by being able to more easily get food. A hermit crab expands the hunting area of the anemone.
Also, anemones will eat leftover food that the hermit crabs don’t finish. They have a unique and intriguing relationship.
The way that marine hermit crabs have adapted to use anemones is remarkable. Hermit crabs are even able to communicate danger to the anemones somehow.
Researchers don’t yet understand how the hermit crabs can communicate with anemones. It’s suspected that it’s either a mechanical form of communication or a chemical one.
Hermit Crabs and Trading Shells
Hermit crabs are actually social creatures. They live in groups and it’s common for them to interact in various ways.
You know that land hermit crabs change shells from time to time. As they grow, they need to find new shells that are more appropriate for their current size.
What you might not know is that hermit crabs have been observed trading shells with each other. Perhaps even more interesting than that is that this can happen in rather large groups.
A group of hermit crabs might sometimes meet up to exchange shells. Researchers have spotted hermit crabs lining up by size to exchange shells.
They will line up from the biggest hermit crab to the smallest. This allows them to exchange shells so that each hermit crab will have the most appropriate shell.
It’s something that shows just how clever hermit crabs can be. These creatures have simple brains, but they’re able to do clever things.
Hermit Crabs and Hiding Inside Their Shells
Most people know that hermit crabs will sometimes hide inside their shells. This is a good way for hermit crabs to escape predators or to stay safe from other threats.
Hermit crabs are capable of fully retreating inside of the shell. Doing this can help hermit crabs to survive attacks from predators.
It’s still possible that the hermit crab could be forced out of the shell. However, it’s a good form of protection that works well in many situations.
Without the shells, the hermit crabs would die rather easily. Their soft bodies cannot survive attacks from predators.
Hermit Crabs Are Scavengers
Hermit crabs aren’t what you would call picky eaters. They’re scavengers that will go around eating whatever they can find.
They’re omnivorous and that means that they will eat plant matter, dead fish, animals, insects, and many other things. Hermit crabs will go around beaches cleaning up the area of dead things.
The fact that they aren’t picky makes it easy to feed them when keeping these creatures as pets, too. You won’t have a hard time giving your hermit crab food that it’ll enjoy.
Learning about various hermit crab adaptations should give you a greater understanding of these fascinating creatures. Both land hermit crabs and marine hermit crabs are truly interesting.
They have adapted to their respective environments in unique ways. Land hermit crabs have modified gills that allow them to breathe oxygen.
Marine hermit crabs have formed symbiotic relationships with anemones. They help each other to survive.
Hermit crabs have displayed cunning in many ways. They’re smart about choosing good shells and they can even work together to trade shells so that each hermit crab has a shell that is the right size.
This should make you appreciate hermit crabs even more. You just might be interested in buying a hermit crab as a pet so you can observe one regularly.
Jeff has always enjoyed having pets, but as a child, he was drawn to his family’s fish tank. Being able to maintain a small ecosystem and observe the behaviors and interactions in the underwater world peaked his interest early on and has kept him hooked until this day. On Avid Aquarist, Jeff shares everything he’s learned about helping aquatic life survive and thrive in a home aquarium.