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Can Hermit Crabs Live in a Fish Tank?

Can Hermit Crabs Live in a Fish Tank?

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The purpose of this blog is to share general information and is written to the author's best knowledge. It is not intended to be used in place of veterinary advice. For health concerns, please seek proper veterinary care. In addition, as an Amazon Associate I earn from qualifying purchases.

There are many, many different animals out there that you can take in as your pet, from four-legged furry friends to reptiles, amphibians, and aquatic animals from all around the world.

With as many different animals as there are to adopt, it would make sense that there are some animals that need a bit more care and research than others, especially when it comes to exotic animals.

Whenever you are taking in a pet that isn’t your standard cat or dog, it is important that you try to do as much research as you can on the animal, what it needs, and what you should be providing for it.

When the information isn’t as readily available to you as it is with other pets, it becomes all the more important to do that research yourself so that your pet can have a comfortable life in its new home.

Take hermit crabs as an example of this. Hermit crabs are unique animals that can make a good addition to an already-standing tank or they can be the centerpiece of the tank itself.

In order to make sure that you are giving your hermit crabs the best life that you can, you need to make sure that you know how to house them and what you should be able to provide for them.

First things first; you should know what kind of environment they should be living in.

Knowing What Your Hermit Crab Needs

The first thing that you should know about finding a home for your hermit crabs is that there are two main types of hermit crabs. There are land hermit crabs and there are marine hermit crabs.

As the names might suggest, this indicates that one type of hermit crab needs to have a fully aquatic environment and the other is a hermit crab that needs to have a predominantly land-oriented enclosure.

Land hermit crabs require a setup that is known as a “shoreline” setup, which offers access to water, sandy surfaces, and an environment that is similar to the natural shores where they can be found, whereas marine hermit crabs need a fully aquatic tank and are the ones who will commonly be living in a fish tank.

To some extent, land hermit crabs can live in a fish tank if you are speaking solely about the type of tank used to house them. A ten-gallon tank (more for a large number of hermit crabs) will often suffice for most land-dwelling hermit crabs.

However, the main focus is on marine hermit crabs, and whether or not these little crabs can enjoy spending time in tanks that already have fish in them. Whether or not marine hermit crabs will thrive in a fish tank depends entirely on the type of crab you are keeping and the type of fish you are keeping.

Housing Marine Hermit Crabs

The first thing to note is that marine hermit crabs do not require that much space within an aquarium.

The common rule of thumb is that there should be one gallon of water per smaller hermit crab, with larger hermit crabs needing about two gallons of water per crab, and you should factor this into the amount of space that the other fish in the aquarium are going to want.

Most marine hermit crabs are saltwater animals, meaning that more often than not, you are going to be working with other saltwater-dwelling animals. There is only one species of marine freshwater-dwelling hermit crab, and these can be somewhat hard to house if you aren’t familiar with housing hermit crabs.

In an ideal environment, having hermit crabs in your aquarium can be beneficial in a number of different ways, as they can help the environment of the tank without being too imposing on the other fish that call the aquarium home.

However, this is dependent on both the type of hermit crab you are working with and the other animals in the tank, as some fish will see the hermit crab as prey.

Think about how hermit crabs coexist with other fish in the wild. In a natural environment, hermit crabs will exist with other fish and invertebrates without qualms or problems, and both animals can go about their days without having to give much thought to the other.

Your goal will be to create a similar setup with your current tank of aquatic animals. You will want to keep hermit crabs with other fish and invertebrates that ignore or are passive with hermit crabs in the wild, and you will want to avoid keeping predatory fish in the tank with the hermit crabs, as they can be easy feeding material.

As a rule of thumb, most species that would normally encounter and ignore hermit crabs in the wild are a good place to start when deciding what you should be housing your hermit crab with.

This includes many reef-dwelling species, ranging from clownfish to butterflyfish, and it also includes other small species such as mandarin fish, royal gramma, and firefish.

You will want to avoid most predatory species, especially groupers, as well as most beaked species. The latter category includes fish such as pufferfish and parrotfish, as these are natural predators of hermit crabs; chances are that if you want to keep hermit crabs, you won’t want them becoming a treat for the rest of your fish.

You can also house multiple hermit crabs together and enthusiasts will often recommend that you should, as hermit crabs are naturally social animals despite their names.

Again, you will want to look more into the details of the exact hermit crab species that you want to keep, as some may be more sociable than others and some may want larger or smaller groups of hermit crabs.

Why Should You Keep Hermit Crabs in Aquariums?

Assuming that your aquarium houses fish that are not predators to the hermit crabs you want to own, it can actually be extremely beneficial for you to keep hermit crabs in the fish tank. This is mainly due to the fact that hermit crabs are scavengers.

In terms of eating habits, being a scavenger means that an animal is willing to eat just about anything it comes across, whether it is algae, a dead organism, or fresh plants.

As such, a group of hermit crabs can make for a nice way of keeping the tank clean of debris and junk, as your hermit crabs will naturally want to eat it and clean up after the rest of your fish.

For example, most people who own fish are aware of how much wasted food their fish can leave behind sometimes, whether the fish aren’t hungry or simply don’t notice the food until it has fallen to the bottom of the tank to collect and rot.

Some fish will eat their food, but may leave scraps behind that can also collect and rot in the same way, which quickly becomes a cleaning hazard for the tank as the decaying organism affects the tank’s water.

Hermit crabs will happily crawl along the bottom of the tank and eat whatever food scraps and forgotten bits your other fish have left, meaning that you don’t have to do as thorough of a check when you are cleaning out your fish tank (though you should still do checks for the sake of all the fish).

They also enjoy eating just about all forms of algae that may be growing on the sides of the tank, keeping your view of the fish inside clear.

Most hermit crabs will eat all forms of algae, ranging from green hair algae to red slime algae, meaning that you also don’t have to work quite as hard to keep the tank clean.

Naturally, you should still do routine cleanings to ensure that the algae doesn’t affect the overall composition of the tank’s water, but your hermit crabs will work as natural tank cleaners for you while being fun to watch and care for.

Keep in mind that if your aquarium environment doesn’t produce a lot of algae or your fish are good cleaners of their food, you will need to make more of an effort to provide food for your hermit crab.

In a fully cleaned tank environment, a hermit crab cannot subsist off scraps alone and still needs food to supplement everything else that it cleans from the tank.

Caring for hermit crabs can be time-consuming and difficult, especially if you are not used to caring for high-maintenance aquatic animals. Making sure that you provide them with the proper home with the right water conditions and fish is crucial in offering your hermit crab a long and happy life.

The exact requirements of what your hermit crab will need from the water will depend heavily on the type of hermit crab you choose to take in.

There are several different kinds of hermit crabs out there, with many of them requiring different needs compared to other hermit crabs, making it all the more important that you find one that can handle the content of the aquarium you want to put them in, both in terms of the water and in terms of the hermit crab’s companions in the water.

As long as you are mindful about this, you can care for the hermit crabs and provide them with long, fulfilling lives.

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