Do Hermit Crabs Eat Fish: Can They Live Together in the Same Tank?

Hermit crabs are scavengers and will eat anything edible, including dead fish. They especially love fish and other seafood items, so make sure to provide them with a balanced diet that includes these items. 

If you’re giving them live bait, make sure it’s small enough for them to eat quickly. If you’re unsure of what they’re eating, place food in the tank and watch them scavenge for it. If they don’t seem to be eating it, it might not be safe for them to eat. In the meantime, make sure any food you give your crab is fresh – if it isn’t, the crab won’t be able to digest it properly and may get sick.

Hermit Crabs in a Fish Tank

A common misconception is that hermit crabs can’t live in a fish tank, but this isn’t true. Be sure to consult with an expert first – they may have some advice on which type of fish is best for your crab-loving friend. Like a fish tank, many hermit crabs prefer living in cool and moist environments. 

If you’re considering adding a fish tank to your home, be sure to do your research and find the right type of fish for your crab-loving friend. Certain varieties of hermit crabs are even capable of eating small fish just like their wild counterparts do! 

Hermit Crabs and Fish Living Together

According to experts, hermit crabs are omnivores that feed primarily on plants and animals. This means that they don’t typically eat small fish. However, if you provide a source of algae—a plant material that hermit crabs love to eat—your crab may be inclined to nibble on some small fish! They should be fine living together as long as you’re careful not to overfeed your crab and fish. And if all goes well, you may even end up with a little crab friend in your fish tank!

Will Hermit Crabs Attack Fish?

Generally speaking, adding a hermit crab to your aquarium shouldn’t cause problems with your fish – but always check with your local aquarium professional before bringing one home!

Hermit crabs are beneficial to fish tanks as they eat decaying plant matter and algae. If you have any concerns about whether or not your hermit crab will attack fish, it is essential to understand that most of them are herbivorous and won’t consume fish. 

However, if you introduce them slowly and watch for any signs of aggression, the odds of conflict should be minimal. If there is any sign that the hermit crabs might start fighting each other, it is best to separate them until they calm down again.

Advantages of Keeping Fish With Hermit Crabs

Keeping fish with hermit crabs can be a fun and educational experience for all involved. Not only does it provide an exciting addition to the tank, but compatibility issues are of no concern – different fish species coexist peacefully together! Plus, the crab colony helps keep the aquarium clean and healthy. In turn, you enjoy fresh food (fish) and clean water daily!

Disadvantages of Pairing Fish With Hermit Crabs

Fish may start to eat the crab’s food which may not be suitable for their health. The crab may also damage the fish tank and furniture due to their movements, making it difficult for them to live in a proper environment. In addition, hermit crabs can get their claws stuck in fish scales, leading to injury.

Fish That Can Live With Hermit Crabs


Clownfish are exciting creatures that deserve our attention. They aren’t fish at all but members of the crab family! They belong to a group of fish known as anemones and live in reef areas worldwide. While hermit crabs will help feed the clownfish by picking up food that has fallen from the reef, it is not necessary to have a fish-eating hermit crab in your tank if you don’t want one. Clownfish are happy living without any other type of food apart from algae and crustaceans.


Damselfish are a great addition to any tank as they get along well with hermit crabs and vice versa. They scavenge for food like hermit crabs, which means that the two species will eat the same things – fish, worms, etc. However, damselfishes can be aggressive towards other fish, so it’s essential to have at least one larger fish in the tank to keep them all in check!

Royal Gramma

Royal Gramma is a type of fish that is great for hermit crabs because it has a high protein content. This means your crab can digest the food more efficiently and won’t get sick as often from overeating unsuitable food. 


Wrasse fish make great additions to any hermit crab’s home. They have a strong jaw and sharp teeth, which help them eat small prey items, making them the perfect fish for hermit crabs. Some other benefits of having wrasses in your crab’s tank include that they prefer warm water environments, so keeping them happy is easy, and they live peacefully with other aquatic creatures. 

Pajama Cardinalfish

The Pajama Cardinalfish is an excellent option if you are looking for a small, easy-to-care-for fish that can be fun to watch in your hermit crab tank. These fish get along well with hermit crabs and don’t require much space – making them perfect companions for those small aquatic invertebrates. 

Although they are naturally peaceful, monitoring these fish closely is always advisable as they can breed quickly. When feeding them flakes, pellets, or live food, ensure you get a healthy specimen because there are many different types of this particular species on the market today.


Guppies are ideal for this situation as they are small, and the hermit crabs don’t eat them. You will also have the bonus of providing food for the hermit crabs! If you already have a fish tank and want to add guppies, provide them with some fruit or vegetables so they have enough food. 

Additionally, if there is no room in your aquarium for guppies, but you have a hermit crab colony living there – it’s ok to release them into another home while still keeping the guppy population under control!

Cleaner Shrimp

If you’re looking for a way to keep your hermit crab’s habitat clean and tidy, consider purchasing cleaner shrimp. These tiny crustaceans eat debris that may accumulate over time, including fish scales and other detritus. This can help ensure a healthy environment for your hermit crab and help them stay fed; this will give them the strength they need to survive in captivity. If you’re interested in introducing cleaner shrimp into your home without worrying about its consequences, purchase them from a pet store.

Fish That Shouldn’t Live With Hermit Crabs

Some fish that should not live with hermit crabs include those with high mercury levels or those that eat other invertebrates. Other types of fish that may not be compatible with a hermit crab’s lifestyle include those that get too large for the crab to handle quickly. Please consult an expert to ensure your fish will fit into the hermit crab’s lifestyle before bringing them home.

Betta Fish

Betta fish are carnivores and, as such, will eat the hermit crab’s food, including its shell. If you decide to keep bettas with hermit crabs, ensure they have their aquarium – a small one is enough! Bettas can live in an artificial tank but must have plenty of hiding places – a piece of driftwood is perfect!


Cichlids are a fish type that should not live with hermit crabs because they can get along, but cichlids will eat hermit crab’s food. If you must have cichlids in your tank with hermit crabs, make sure to provide them with their separate aquarium or tank so the cichlid won’t be able to prey on the hermit crab and vice versa.

How Do Hermit Crabs Hunt and Forage for Food?

Either way, they use their antennae to detect prey in the water. Some hermit crabs eat small fish and other invertebrates, while others scavenge food from the sea floor. Surprisingly, they don’t have teeth- instead, they grind their food with solid gizzards before eating it. 

What Do Hermit Crabs Eat in the Wild?

In the wild, they typically eat small invertebrates like salps and nematodes. However, if you provide them with a diet of seafood (frozen or fresh), they will be happy as can be! Keep in mind that it’s essential to keep your hermit crab well-fed so that it doesn’t get territorial, and start eating fish instead!