Can Crabs Live with Goldfish?

Many people enjoy keeping goldfish as pets, often in a community tank with a few suitable tank mates. 

Goldfish are peaceful creatures that get along well with most other non-aggressive fish species and with most large aquatic snails. Freshwater crabs can also make fun pets, especially for kids. So, why not keep the two species together in one tank or pond?

But can freshwater crabs live with goldfish? 

Sadly, we don’t recommend keeping goldfish and crabs together in the same habitat.

Read this guide to learn why keeping freshwater crabs in the same tank or pond as your goldfish is such a bad idea.

Can Crabs Live With Goldfish?

We don’t recommend housing goldfish and crabs together in the same tank.

But why?

  • Although goldfish are typically peaceful, gregarious fish that enjoy the company of their own kind and other similar fish species, they are opportunistic omnivores that could regard your pet crabs as a potential food source.
  • Some freshwater crab species can be highly territorial, which could potentially lead to conflict with the goldfish.
  • Crabs tend to be less tolerant of fluctuations in water parameters than goldfish.
  • Many crab species need much warmer water than goldfish can tolerate.
  • Some freshwater crabs have very large claws that could inflict injuries on the goldfish.

For all those reasons, keeping crabs in the same tank or pond as goldfish is not a good idea.

Can Crabs Live In A Fish Tank?

Yes, you can keep some crab species in a fish tank. However, it’s important to know that not all crabs are suitable for life in an aquarium and have different care requirements depending on the creature’s variety and size.

Here are some of the main things you need to consider if you’re thinking about keeping freshwater crabs in a fish tank.


Some crab species are more suited to aquarium life than others, so you’ll need to carefully research the species you’re considering keeping to be sure that your tank size and water conditions are suitable.

Popular species for home aquariums include the Red Claw crab, Fiddler crab, and Thai Micro crab, although there are others. All these species are typically smaller in size and have features that make them pretty adaptable to life in a fish tank.

Tank Size

Crabs need a tank size that’s big enough for their needs. The environment must be spacious enough for the crab to move around, molt, and explore comfortably. Although the correct tank size varies between crab species, I recommend using a 10-gallon tank or larger for most species.

Water Parameters

If you keep crabs in a fish tank, you need to ensure the water parameters are appropriate for the species you intend to buy. 

Be sure to carry out plenty of research into the temperature, pH, and water hardness that the crabs need. 


All tank-kept livestock does best if you create a habitat that mimics the species’ natural environment. In the case of crabs, that often includes providing a mixture of water and land areas, hiding places, rocks, driftwood, and other climbing surfaces.

The more varied and diverse the environment, the better the crabs will like it. However, that’s not necessarily suitable for your fish, so again, do some in-depth research before deciding on the crab and fish species to choose and setting up the tank.


Crabs are opportunistic, omnivorous scavengers that have very diverse dietary needs. In the tank setting, the crabs’ diet can include commercial crab food, sinking pellets, algae, occasional meaty treats, and veggies.

That said, each species is slightly different, so do your research first so that you can provide your pets with a balanced, appropriate diet.


Some species of crabs are aggressive or territorial and will hassle slow-moving fish, such as Fancy goldfish. Before buying a crab to keep in your fish tank, double-check that the species can coexist peacefully with the other invertebrates and fish in your aquarium.

Pond plant

Can Crabs Live In A Pond?

Most goldfish varieties can do pretty well in a pond setting, especially when kept with similar species and in a temperate environment where the winters are mild. So, what about crabs?

Freshwater crabs can live in various aquatic habitats, including rivers, streams, lakes, and ponds, and can thrive in your garden pond, provided the conditions are suitable for the crabs’ needs. 

That said, there are a few important things to consider before adding crabs to your pond.

Water Quality

All freshwater crabs need clean, well-oxygenated water to thrive, so you need to ensure that your pond is free from harmful pollutants and has an efficient, well-maintained filtration system.


Most freshwater crab species like a water temperature between 68o and 86o Fahrenheit, which is too warm for most goldfish varieties since they are coldwater fish.


Crabs like lots of places to hide and structures they can climb up, including rocks, wood, and plants.

That type of environment is perfect for pond fish, too, provided you don’t clutter up too much of the fish’s swimming space.


Crabs are omnivorous, eating a variety of foods in the pond environment, including small invertebrates and some plant matter. 

Although the crabs will find a certain amount of food in the pond itself, you’ll need to supplement that with commercially produced crab foods to be sure the crabs receive all the nutrients they need to grow and thrive. In particular, you need to ensure the crabs have sufficient calcium in their diet to keep their shells strong and in good condition.


Some fish species and turtles will make a meal from a nice, juicy crab, so you need to check that your pond inhabitants are compatible with whatever crab species you decide to introduce.


In some states, keeping certain species of freshwater crabs in a garden pond is illegal, so you’ll need to check with your local authority before you add your new pets. 

That’s largely the case in areas where escaped crabs could impact local native wildlife populations and are regarded as an invasive alien species.

Do Crabs Eat Goldfish?

Crabs don’t generally eat goldfish, largely because goldfish are too big to make a suitable prey item. In addition, most goldfish varieties are fast enough swimmers to escape a would-be predatory crab. However, goldfish fry and eggs could make an easy meal for a hungry crab, which is frustrating if you’re trying to breed your goldfish.

That said, individual crab species’ behavior and dietary preferences vary, and there could be exceptions or unique circumstances where a large, strong, freshwater crab might attempt to grab a goldfish if the opportunity arose.

Do Goldfish Eat Crabs?

Like crabs, goldfish are omnivores with a reputation for eating pretty much whatever easy meal comes their way. That generally includes small invertebrates, worms, plant matter, and algae, so in theory, a tiny freshwater crab could be considered as food. You can also feed your goldfish commercially prepared goldfish flakes, frozen bloodworms, daphnia, brine shrimp, and the like.

Depending on your crab species, a large goldfish could try to eat it, although the fish’s mouth would probably be too small to cope with a larger crab. However, goldfish are typically nosy creatures that might nibble on the crab’s legs, potentially causing injuries.

I once made the mistake of introducing a few large Amano shrimp to my goldfish tank as a cleanup crew. Unfortunately, the goldfish immediately began hassling the shrimp, and when I checked later that day, two of the shrimp had mysteriously disappeared. 

I assumed they were hiding away from the goldfish among the dense plants or in one of the caves I’d included in the setup. However, all the shrimp had vanished the following day, and my goldfish looked very well-fed and smug!

So, I reckon if the crabs were small enough, the goldfish would most likely try to eat them!

What Type Of Goldfish Can Live With Crabs?

Unfortunately, because of their very different needs in terms of temperature, habitat, and diet, no goldfish varieties can safely live with freshwater crabs.

Pros and Cons Of Keeping Crabs With Goldfish

So, now you know that goldfish and crabs don’t make a good combination of tank or pond mates. But so you can be sure, here’s a quick summary of what’s good and not so good about trying to keep these two species together.


Here’s what could be good about keeping goldfish and freshwater crabs together in a pond or tank.

  • Goldfish look beautiful, cruising sedately around a well-appointed tank filled with plenty of attractive plants and decorations. A few freshwater crabs can bring a new dimension of visual interest to your aquarium with their quirky behavior and unique appearance, contrasting beautifully with the goldfish.
  • Freshwater crabs are natural scavengers that will eat algae, leftover food, and detritus, helping to keep the tank clean, reducing organic waste, and reducing the bioload on your filter system.


So, there are a couple of potential advantages to keeping crabs and goldfish together. However, the list of reasons why not to do that is pretty long!

  • Although goldfish are peaceful creatures, they can be nosy and enjoy nibbling on anything that might be a food source, including a crab’s legs. That’s sure to stress the crabs and could even result in death.
  • Goldfish eat small crustaceans, and that could include tiny crab species.
  • Most freshwater crabs come from tropical or semi-tropical habitats where the water is much warmer than is comfortable for goldfish. That’s going to make providing a suitable environment for both species extremely challenging, especially in a pond setting.
  • Both freshwater crabs and goldfish need plenty of space to live comfortably. Goldfish require a large tank to accommodate their adult size with plenty of open water swimming space. In comparison, crabs need ample space to climb and move around, so the two species’ tank decoration setup requirements are totally different.
  • Goldfish produce a significant amount of waste, which will lead to poor water quality if you don’t keep on top of maintenance and cleaning tasks. Crabs also produce a fair amount of waste, so you’ll need an extremely powerful canister filter system and powerheads to keep the water clean and safe for both species.

So, on balance, you can see why crabs and goldfish don’t make suitable companions in either  a tank or pond.

Pond plant

What Fish Species Can Live With Freshwater Crabs?

Even though goldfish are not compatible with freshwater crabs, some species can safely share a tank with them.

However, it’s important to remember that some crabs are more aggressive and territorial than others, and you’ll need to keep in mind both species’ habitat requirements.

Small Peaceful Community Fish

Some small, peaceful community fish species can coexist with freshwater crabs, including:

  • Guppies
  • Tetras
  • Platies
  • Mollies
  • Swordtails
  • Cherry barbs

These fish species are small enough not to pose a threat to the crabs and fast enough to keep safely out of the crabs’ way.

Bottom-Dwelling Fish

Fish inhabiting the fish tank’s bottom regions can make a safe combination with freshwater crabs, including Corydoras catfish, Khuli loaches, and Otocinclus catfish.

Large Peaceful Fish

Some larger fish species can tolerate freshwater crabs and won’t hassle or try to eat them. Some of the more peaceful cichlids, such as Angelfish and Keyhole cichlids, can do well with crabs, as can larger gouramis.

However, I stress that you must do plenty of research to check for species compatibility before choosing your fish or crabs.

Final Thoughts

I hope you enjoyed our guide to whether crabs can live with goldfish. If you did, remember that sharing is caring, and take a moment to hit the share button above!

Although aesthetically, crabs and goldfish would look fantastic in a well-appointed fish tank or pond, keeping the two species together is not recommended. There are too many differences in the creatures’ habitat requirements and behaviors to make keeping them together a practical option.

However, why not keep goldfish and crabs in separate tanks so that you get to enjoy the fun of keeping both species?

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