Can You Keep Crayfish With Other Fish?

Can You Keep Crayfish With Other Fish

Crayfish can be a beautiful and exciting pet to own, particularly for true lovers of aquatic life. These creatures, with their vibrant colors and unique way of navigating the world, are incredibly desirable as pets because they are such a unique addition to any tank. They are sometimes considered more interesting to watch than other aquatic life (like fish, shrimp, or snails).

However, despite the fact that these tiny predators can be a ton of fun to own, crayfish might not be a good fit for your fish or shrimp tank. In fact, depending on what kind of setup you have, you probably dont want these creatures anywhere near the rest of your fish.

When you look at a crayfish, it is pretty easy to take immediate note of their claws. These creatures are not just excellent scavengers but predators and nature has equipped them with the tools to catch a delicious meal with absolute ease.

While they might seem too small to be truly dangerous to us, a crayfish is actually a pretty big threat in a tank setting. These creatures are surprisingly fast, and their claws can do some very serious damage to anything that they manage to catch.

The Instinct of Opportunistic Feeders

These creatures are beautiful, but they are opportunistic feeders meaning that they will eat almost anything that is available in the tank. So, don’t be surprised when your crayfish will truly and actively hunt your fish or shrimp.

It is the nature of the crayfish to find something that they can hunt. It is something that they will do on instinct. While it might be nice to consider a world where all of your beautiful fish can live together to create a stunning community tank, the fact remains that these animals are wild no matter what steps you take to make them into pets.

Your fish will swim around the tank darting around wildly, and your crayfish will look at them like the prey that they would be in any other environment. Even if you find the right diet for your crayfish, these animals will still continue to hunt your fish (given a chance).

This makes them a fairly significant threat to anything else that you might put in the tank alongside them. They are an even bigger threat to small fish that might swim near them. You should count on your crayfish attacking your other fish more than you should count on your other fish being able to actively avoid being attacked.

Crayfish and Potential Aggression

Crayfish are an obvious threat to fish in your fish tank, but the reality is that they might also not catch anything. This is what makes many people consider the idea that it might be fine to bring a crayfish into their community tank. However, this is probably not the best course of action.

Though your crayfish might not succeed in catching any of your fish, the fact of the matter is that their presence alone will be damaging for your poor fishy friends. The truth is that having an active predator lurking in close proximity to your fish can do a lot of damage to them.

You might not think about the psychology of fish too much, but when you think about any animal being confined to a small space with something that could realistically kill it, you can understand with ease why this might be stressful for the animals in the tank.

Note: Multiple studies show us that fish sense predators. Constant stress makes them weak and vulnerable. Actually, this behavior is not limited to fish and could very well apply universally to shrimp, snail, and other animals (for example, even dragonfly nymphs can feel the predatory fish around!).

It is easy to overlook the emotional state of a fish for some people, but the fact is that stress can have significant impacts on your fish. They are likely to suffer from shorter lifespans and might experience additional side effects that could have an overall impact on their comfort and health.

Crayfish in Community Tank. Tips

In the event that you do plan on adding aggressive crayfish to a tank with other fish or shrimp, there are a couple of precautions that you might want to take.

A possible option is to wrap the claws of the crayfish. While this might not be comfortable for them, it is a commonly taken precaution due to the fact that it makes it easy for people to safely handle their crayfish. A crayfish will also grab a finger if given the chance, so this makes them less of a threat. However, it is not considered to be a great thing to do for extensive periods of time.

Note: Some people even chop off the lower (inner) part of the claws. Please, do not do that. This is pure barbaric!

Read more about it in my article “Do Crabs, Crayfish or Shrimp Feel Pain?”.

A less problematic option includes providing your fish (and/or shrimp) with plenty of areas to hide. Adding the right pieces to your tank will allow them to hide from the predator and find a safe place to spend time.

This can help to alleviate any anxiety that they might be feeling and will offer them a safe harbor among the dangers posed by the crayfish being in the tank. However, this is not a foolproof plan and still forces you to rely on the likelihood that the fish will not accidentally end up getting snagged by their clawed tank-mate.

Next, DO NOT ever keep crayfish with bottom dwellers. Give your fish at least a chance to survive, pick only fast swimming top or mid-dwelling fish.

The tank size also matters. Big aquarium will let your fish have more space to roam around and avoid a crayfish.


Instead of aggressive species like Blue crayfish or Red crayfish, choose small and less aggressive species of crayfish, like Dwarf Mexican crayfish. Read my article “Dwarf Mexican Crayfish  – Detailed Guide: Care, Diet, and Breeding”.

Crayfish and Big Fish

Sometimes people think that the size of the fish can guarantee its safety. Personally, I do not completely agree with them, unless it is big enough (or aggressive, like Pufferfish) to eat it.

Crayfish can react (attack) defensively even when there is a bigger opponent in front of them. So, even fish that are bigger than them run a pretty significant risk of sustaining damage from an attack. When you consider the fact that these fish would then be injured, potentially get sick, and trapped with the crayfish, you can see with relative ease what the problem here is.

Even if you think that your fish are too large or fast for a crayfish, it is important to remember that it can injure fish enough to kill it at a later time.


Crayfish make for great pets and can be exciting additions to a tank. They are unique creatures with fascinating habits that can be fun to watch. Many people find them to be interesting and unique pets that can bring something special to a room.

However, at the end of the day, it is important to remember that these creatures are considered to be predators. They really are better suited to be on specific environments, preferably where they can’t hassle the other fish, shrimp, or snails.

With that being said, there are some fish that are known for being okay around crayfish. The problem is that you will always run the risk when you mix these small crustaceans with other fish. Always be wary of adding them to a tank with other aquatic life unless you have done extensive research. They are animals and will have their own agenda, so act accordingly.

Related post:

  1. Introduction to the Crayfish Care – Setup, Diet, and Facts
  2. How to Set Up a Crayfish Tank
  3. What Do Crayfish Eat?
  4. Crayfish and Suitable Tank Mates

3 thoughts on “Can You Keep Crayfish With Other Fish?

  1. We bought a small crayfish last week, after 2 days he appears to have disappeared, any ideas? Don’t have any large fish only a few silver Mollies but they are quite small, searched the tank, moved big items around but can’t find him anywhere.

    1. Hi Clive,
      What crayfish species did you buy?
      The point is that many species burrow to avoid predation, dehydration, and environmental stress.
      Best regards,

  2. I accidentally stumbled on solution to peace…my crayfish lost both his claws …wa la ….no longer threat to community…he now stays hidden …at least till he grows claws back if ever….

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