7 Blue Crayfish Tank Mates – List of Compatible Species

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If you’ve fallen in love with the famous blue crayfish, at first sight, you’re not the only one. These large and handsome invertebrates are great for beginners due to the low level of care required and their hardy nature.

The blue crayfish isn’t too sensitive to poor water conditions and eats pretty much anything that has any nutritional value.

But, as the story goes, a single crayfish doesn’t make for much of a spectacle. Sure, the animal is gorgeous, but it can get lonely in there with just one crayfish crawling around.

So, you need to consider some good tankmates to keep the crayfish company. The problem is that this crustacean is very aggressive and will eat, attack, and bully any fish that wanders into its personal space.

You need to handpick the crayfish’s tankmates carefully to prevent that. Let’s see how you can do that!

Best Tankmates for Blue Crayfish

While crayfish are omnivorous, they come with predatorial behavior and extreme aggression, making them unfit for community tanks.

But you can make it work with a bit of know-how and awareness.

Today, we will look into 7 of the most compatible tankmates for your blue crayfish. Let’s get it going!

1. Tetras

Tetras are active, energetic schooling fish that populate the tank’s middle area. They thrive in larger groups which are easy to keep, given that tetras only grow up to 1.5 inches.

These fish can live up to 5 years in good conditions and can populate both small and large tanks, depending on your needs.

The ideal setup for them includes:

  • At least 10 gallons of space for a small group (4-6 fish).
  • Temperatures around 68-79 F.
  • Plenty of plants and hiding areas.

An omnivorous diet is necessary to keep your tetras in good spirits and impeccable health.

Compatibility – High

Tetras use group strength and speed to escape the crayfish’s claws. They will dart across the tank at the smallest sign of danger and will soon learn to avoid the crayfish altogether. This being said, you should never count the crayfish out.

After all, the crustacean is locked in the tank with the fish, so you should expect some casualties with time.

Fortunately, tetras are hard to catch, especially if they have a lush ecosystem with plenty of hiding areas at their disposal.

2. Rasboras

Rasboras follow the same recipe that tetras use. They rely on group strength, speed, and hiding to avoid any predators that may target them.

The larger and slower crayfish cannot catch up with the small and fast swimmer.

Rasboras can reach 1.75 inches and require to live in larger groups, preferably 8 members and up. Aim for temperatures of 73-82 F and house your rasboras in a lush environment with plenty of live plants.

These fish feel safer and more comfortable in a darker and richer ecosystem with a variety of hiding areas.

Compatibility – Moderate

The problem isn’t that the blue crayfish can catch your rasboras but that they don’t share quite the same tank conditions. The temperature is a more sensitive topic, given that the highest acceptable temperature for crayfish is 75 F.

This value is almost the minimum acceptable for rasboras, as they shouldn’t go lower than 73 F.

Naturally, you can make it work, but you don’t have much wiggle room at your disposal.

Another problem would be rasboras’ breeding difficulty. This means that you can’t afford to lose too many rasboras to your crayfish.

These fish need specific water conditions to breed, including minimum temperatures of 76 F, preferably closer to 80 F. So, you need a separate breeding tank for them.

3. Danios

Danios are slightly larger than the previous species but function based on similar requirements. These are also shoaling fish that require group support and will thrive in a variety of environmental conditions.

Your typical danio fish can reach 2 inches at most, although most specimens will remain smaller than that.

These are peaceful but energetic fish that can share space with many species similar in size and temperament.

Zebra danios are also adaptable and resilient, capable of withstanding impressive temperature variations, although not for long. Cold waters may make them more prone to diseases.

Compatibility – Moderate

This species’s temperature compatibility isn’t a problem, as they have the same temperature requirements as the crayfish. The problem is the fish’s curiousness and confidence.

Zebra danios are known as fin nippers, as they are attracted to flappy and colorful fish. The crayfish isn’t exactly flappy, but it checks the color box.

This means your danios may be too curious about the crayfish, which can spell their end fast.

Fortunately, these are fast learners, so they will quickly adapt to the crayfish’s presence. They also prefer to dwell in the tank’s upper areas, so they’re unlikely to run into the crayfish too often.

4. White Cloud Minnows

White cloud minnows are great for any community setup, thanks to their peacefulness and adaptability. These are docile swimmers that enjoy their group living in a peaceful and safe habitat.

The typical mountain minnow won’t go beyond 1.5 inches, allowing them to maintain a low profile in the tank.

These fish need clean waters, moderate water currents, and a lush ecosystem with plants and various decorations.

Some open swimming area is also necessary to give the fish the room it needs to explore its surroundings. Mountain minnows are easy to breed in captivity with or without a breeding tank.

Compatibility – High

These fish make for decent tankmates for your crayfish, primarily due to their size, speed, and group lifestyle. The blue crayfish will have difficulties catching them, eventually causing the murderous crustacean to lose interest.

I recommend creating a lush ecosystem with a variety of hiding areas and a varied landscape to increase your fish’s survival rates.

It also doesn’t hurt that white cloud minnows are easy to breed, just in case your crayfish gets its claws on some of them.

5. Tiger Barbs

We’re upping the odds with this one, as tiger barbs go in a different direction that the previous species.

These fish can reach 3 inches in optimal conditions, so they’re not exactly small, compared to the species we’ve discussed so far. These mid-dwellers prefer to live in groups and can live up to 6 years or more in ideal conditions.

Tiger barbs are omnivorous and eat mostly anything, and they showcase a vivid temperament, always on the run.

These fish will patrol their environment around the clock, investigating anything that looks out of the ordinary. Such as a big, mean, blue crustacean moving on the substrate.

Compatibility – Moderate

These fish are larger than the previous ones, which automatically puts them at risk of becoming food for your crayfish. The difference is that tiger barbs know how to take care of themselves.

These fish rank as semi-aggressive, so they’re unlikely to go down without a fight. 

Your tiger barbs are capable of intimidating the crayfish, especially when kept in groups larger than 5 individuals.

However, you should provide your barbs with some aquatic decorations just in case the confrontations don’t go their way.

6. Silver Hatchetfish

This is a fish species that you probably didn’t expect to land on today’s list, but it will make sense in just a second. Hatchetfish are tiny peaceful predators which sounds awkward, to begin with.

These fish only grow up to 1.5 inches, but don’t let their size trick you; they are avid predatorial carnivores with a foul temperament at times.

These fish like to live in groups and dwell mostly at the water surface for easy food access. They are also quite shy, so they should have a variety of plants and other hiding areas available for emergency retreats.

You need to house them in groups of at least 6 individuals, for which you need at least 20 gallons of space.

Compatibility – Low

This is a tricky one, primarily due to the temperature requirements. Hatchetfish require water temperatures around 74-83 F which contrasts strongly with the crayfish’s maximum temperature of 75 F.

You don’t have too much room to work with, that’s for sure. This is the main issue that will most likely break the deal.

This being said, if you do manage to circumvent the problem and find a goldilocks zone for both species, you have no other problems to solve.

The hatchetfish lives near the surface and prefers to eat floating foods. It’s unlikely it will run into the crayfish, given that the crustacean only leaves the substrate occasionally to breathe.

7. Red-Tailed Shark

Red-tail sharks are gorgeous bottom dwellers with a beautiful presence but a foul attitude. These fish can reach 6 inches in captivity and live up to 8 years in optimal conditions.

They are slim, athletic, territorial, and don’t play well with others. They will patrol their habitat relentlessly in search of food and intruders to pick on.

You need at least 55 gallons for your red-tail shark and an optimal temperature range between 72 and 79 F.

This omnivorous fish needs a varied diet and a variety of caves, plants, and other hiding areas for exploration and resting purposes.

Compatibility – Moderate

The red-tail shark is larger than the crayfish, which minimizes the risks of the crustacean attacking or killing the fish.

It also helps that the shark is a no-bullshit species that’s always ready to spar with any intruders, be them fish, crayfish, or any other species.

Thankfully, red-tail sharks prefer to keep a low profile and stick to their comfort zones to avoid other tank occupants. They are also fast swimmers, capable of getting out of the danger zone fast.

As an end-note, don’t take any of these fish species for granted. While they may seem like crayfish-compatible on paper, you never know what may happen in the actual tank.

Crayfish are unpredictable animals with a killing mentality and unhinged behavior. They will try to kill your fish, given the opportunity, as it’s in their nature to do so.

Fortunately, you can prevent or at least minimize these risks by:

  • Increasing the tank’s size – The extra space will allow your fish more room to flee danger because the danger is always present in a crayfish tank. You also have more room to add plants, rocks, and other elements that can hide and protect your fish.
  • Monitoring the environment – Some fish will adapt better to the crayfish environment, but this doesn’t mean that accidents can’t happen. Always monitor your aquarium to assess the relationship between your crayfish and fish. This allows you to act fast in case of elevated tensions to mitigate some of the violence.
  • Resetting the whole deal – Maybe your current fish can’t cope with the crayfish too well. It may be due to temperature differences, different layout requirements, or simply increased stress due to the crayfish’s constant predatorial behavior. If that’s the case, you should reset the whole deal and find different fish for your crayfish tank.

Not that we’ve settled this matter, let’s consider another interesting topic.

Worst Tankmates for Blue Crayfish

Naturally, there are considerably more incompatible crayfish tankmates than compatible ones.

Instead of naming them, I’ll give you some overarching principles to consider when assessing which species are unfit for your crayfish tank:

  • Slow swimmers – These are great additions to your crayfish tank if you want your crayfish to eat them. Slow swimmers are easy targets for the crayfish’s deadly claws and are only good as feeder fish, not as tankmates.
  • Bottom dwellers – These are out of the question as well. Some species may work their way around the crayfish, as is the case with the red-tail shark, but most won’t. You want to stay away from bottom dwellers as these will share the same dwelling space as the crayfish. And you don’t want your sheep to run along the wolves.
  • Large and aggressive fish – Stay away from aggressive cichlids or other aggressive and territorial fish that could attack the crayfish. This crustacean may be violent, but it’s not unbeatable; sometimes, it’s the fish themselves that occupy the higher position on the food chain. Cichlids may not be able to kill the crayfish, but they can nip, bully, and attack it frequently, causing the crustacean to stress out and look to leave the tank.

You want to prioritize fast, semi-aggressive species that prefer different dwelling areas than the crayfish.

And even then, you’re not in the clear, as this is one mean and unpredictable crustacean.


There’s no denying that the blue crayfish is a handsome aquatic pet, perfect for all levels. But it’s also crystal clear that this animal doesn’t like tankmates. I’ve provided you with a list of somewhat compatible species, but don’t take it for granted.

If my opinion matters for anything, I advise against housing your crayfish with any fish species. But I understand why you would ignore it.

At least consider my list and always choose cheap and readily available species that you can replace with ease in case the situation backfires. Which most likely will.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
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