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Hermit crabs make great low-maintenance pets, especially for busy families or small children who are just learning to take care of animals. But sometimes, their tanks can look a little sparse, since hermit crabs love to burrow and hide in small spaces.
Is there anything that can safely and easily live in there with them? As any owner knows, hermit crabs live in terrariums where you must create a tropical environment, but that doesn’t mean that you can add any animal that lives in the same kind of environment.
Some animals are natural predators or prey of the hermit crab, while others are incompatible for other reasons. Below, we will run through different types of animals that can live nicely in a terrarium with your hermit crabs, as well as some that can’t.
If you still have questions or need further clarification, you can try to find a knowledgeable sales representative at a pet store, but your best bet is to consult a tank expert who specializes in salt water animals.
What Do Hermit Crabs Need to Live?
Before we get into talking about specific species that can cohabitate with hermit crabs, we thought it might be helpful to go over some basic requirements for hermit crab environments. That way, as you look for neighbors and friends for your hermit crabs, you can quickly check their living requirements against those of your crabs.
In their environment, marine crabs need relatively warm salt water, and both types of hermit crabs (land and marine) need warm, humid environments. They also need the right type of lighting, which is best achieved using special LED lights.
One of the most important things that hermit crabs need is water, and this goes for both marine and land-dwelling crabs. They breathe through gills, so even the land-dwellers need to keep their gills wet to breathe.
The nitrates and nitrogen content of their environment must also be regulated. Before you introduce hermit crabs into their tank, you must finish a whole nitrogen cycle, which is a process that takes several weeks.
Hermit crabs need places to climb and move around to stay healthy. You need a sand substrate and lots of rocks, and don’t forget shells in a variety of sizes as well, for when your crabs grow and need new homes.
You should include some plant life that absorbs nitrates to promote a healthy tank. Varieties of seaweeds are great for this, and they create a realistic look for your aquarium as well.
For food, hermit crabs eat various species of algae and other plant life. In the wild, they are scavengers and will eat many plants and small organisms that they come across, including other dead marine animals; you can occasionally give them a dead sardine in their tank as a special treat.
You should make sure your hermit crabs get a variety of items in their diets, including different types of algae, plants, and special hermit crab pellets, which deliver a lot of their other nutrition. Their diet actually makes them great additions to larger tanks, since they help filter out unwanted algae and other decaying matter in the substrate.
It’s important to take good care of hermit crabs. Scientists have shown that crabs are not only capable of feeling pain, but they also remember it, which is pretty remarkable given the size of their brains and what we knew about them previously.
Finally, did you know hermit crabs can live up to 30 years? Getting a hermit crab is, therefore, quite a commitment!
Now, let’s read about some other animals that can cohabitate peacefully and healthily with hermit crabs.
1 – Other Hermit Crabs
While technically not another type of animal, hermit crabs cohabitate with their own kind very well. In fact, hermit crabs are fairly social animals, and they will thrive better with a community of kin.
You will need a terrarium with at least five gallons of space for every pair of crabs you have. You will also need to make specific accommodations for your crabs depending on their sizes.
Did you know that there are multiple types of hermit crabs? Aside from the larger groups of marine hermit crabs (most common) and land hermit crabs, there are Blue Leg or Dwarf Leg Hermit Crabs, Coconut Hermit Crabs, Ecuadorian or Pacific Hermit Crabs, Electric Blue Hermit Crabs, Scarlet Reef Hermit Crabs, and Strawberry Hermit Crabs.
In total, there are over 800 species of hermit crabs on earth, and there may even be more that we haven’t classified yet. That way, if you want a variety of types of animals in your tank, you can technically achieve this just by getting different varieties of hermit crabs.
Typically, you can mix different types together and they will get along fine, but be sure to place many shells of multiple different sizes in your tank for them. Otherwise, they may fight each other for shells that they need as they grow.
While they live well with others of their own kind, close relatives are usually a no-go. Hermit crabs don’t do well with other types of crabs, especially fiddler crabs.
2 – Lizards and Reptiles
Generally, lizards and reptiles don’t work well with hermit crabs.
In some cases, they become predators or prey, but mostly this is because they require different kinds of environments and just don’t live well together. In other words, they aren’t likely to add to each other’s experiences and may even cause immense stress and premature death.
If you do decide to get a lizard or reptile for your terrarium, you need to make absolutely sure that it is well-suited for a tropical environment; many reptiles and lizards are actually desert dwellers, so the high moisture would cause them a lot of suffering.
Sometimes, aquatic hermit crabs can live with turtles, as long as they are both well-suited to the same climate and conditions. That said, they won’t interact at all and are actually very different animals, so it might not make very much sense to house them together.
Some hermit crab keepers have reported that their crabs live rather comfortably with the Crested Gecko, but be sure to do some research of your own before buying one.
3 – Fish
Being marine or semi-marine animals, it makes sense that hermit crabs might live well alongside fish. This is the case, some of the time.
First, to keep both fish and hermit crabs together, you obviously need aquatic/marine hermit crabs. You want to make sure that the fish you want need the same type of water as your hermit crabs (temperature, salination, and other conditions).
Reef-dwelling hermit crabs live best with small reef-dwelling fish. They cohabitate well with Butterflyfish, Cardinalfish, Clownfish, Damselfish, Firefish, Gobies, Mandarin fish, Pajama fish, and Royal Gramma fish especially.
4 – Insects and Other Small Animals
There are some insects that live well with hermit crabs and help maintain homeostasis in the terrarium, but most of them are small, and can actually cause problems in your home if it becomes infested.
You want to avoid insects in general, more for the reason that they can become invasive, in either your environment or the crabs’.
Isopods, which are a type of crustacean, live well with hermit crabs, and even help to keep the tank clean. There are many different types of isopods, so do some research on which ones live best in the type of environment you’ve created in your terrarium.
Springtails, which look like small-sized insects but are actually arthropods, can also live well with hermit crabs. Like the isopods, they help keep the tanks clean; however, you don’t necessarily want them getting out of the tank and into your home, so use caution if you decide to add them.
5 – Consider Plants
While hermit crabs can be particular about the other animals in their tank, plants are very good for them, and they love them. Hermit crabs will use plants to climb on, hide behind, and eat.
Hermit crabs prefer certain types of plants, including air plants, which are beautiful and don’t require watering; bromeliads, which don’t need soil and are quite colorful; moss, which is naturally occurring in most hermit crabs’ natural habitats; spider plants, which are very easy to grow and require little maintenance; and sprouts, which provide hermit crabs with important nutrients.
What Not to Put with Hermit Crabs
As we have learned, there aren’t a whole lot of animals that can live with hermit crabs, but there are quite a few that can’t.
For example, you might be tempted to put some fish in your tank with them, but apart from the list given above, there are not a lot of fish that can live well with hermit crabs. What’s more, the fish listed can get a bit expensive.
In addition, several types of insects are poisonous or venomous for hermit crabs, including centipedes and millipedes.
You obviously want to avoid any animals that eat hermit crabs. Some species of fish, especially beaked fish such as Pufferfish, are dangerous to hermit crabs, but most of their predators would be too big to fit in a tank at home, anyway.
While several other animals threaten hermit crabs, that doesn’t mean hermit crabs are always harmless. Hermit crabs pose a danger to snails, since they eat them and steal their shells.