Last update: November 15, 2023

13 Best Blue Crayfish Tank Mates

There are few additions to an aquarium more striking to look at than a Blue Crayfish, but these iconic creatures do come with some risks. As large, omnivorous crustaceans, they are likely to try and eat the fish that they live with – but that doesn’t mean they have to be housed alone.

To help you decide, we’re going to outline the best blue crayfish tank mates.

Perhaps surprisingly, many hobbyists find quite a variety of different fish will be able to live happy and healthy lives alongside a blue crayfish or two – though there will always be at least some possibility of conflict.

Blue Crayfish Tank Mates: What To Know

There are a few things that you need to be aware of before you decide to put any animals into the same environment as a crayfish.

Food and Competition

Firstly, you need to accept that crayfish are slightly dangerous to other fish because they prefer to eat animal protein and will likely try and make a meal out of anyone in their tank that is small enough. They are omnivores, however, and can easily survive on plant matter and fish food alone.

Therefore, choosing tank mates for them is all about making sure the other fish are going to stay safe, or they are going to keep breeding. Many people like to house live breeders with crayfish so that new young fish are regularly being born, in case any do become prey. Otherwise, you can select larger or faster fish that your crayfish simply can’t catch and harm.

Water Parameters and Tank

Perhaps the most important consideration for any community tank is ensuring that all the inhabitants are comfortable living in the same kind of water and with the same kind of tank setup. Blue Crayfish need to have:

  • Water Type: Freshwater
  • Tank size: 30-gallon
  • Water hardness: 2-10 dH
  • Water temperature: 64 – 77°F
  • Water pH: 6.5 – 7.5


Despite their size and tendency to try and snack on any fish that get a little too close, Blue Crayfish are actually not very aggressive. They can be quite active and like to roam around, but they are mostly peaceful and friendly.

Good tank mates for them should be able to get out of the way of their claws, though, and preferably spend most of their time towards the top or middle parts of the tank. This will make it less likely that altercations will occur.

Adult Size

The size of the fish that you include with your Crayfish is also a very significant factor in whether or not the tank is going to be a happy one. Smaller fish are more likely to become food so live breeders are best when they are this size, whereas fish that are a little bulkier and heavier will be less vulnerable.

Blue crayfish usually grow to around 4-6 inches, so anything from 2.5 – 3 inches upwards should be safe from harm.

The Best Blue Crayfish Tank Mates

So, let’s take a look at some of the tank mates that tend to work well with Blue Crayfish, so that you can start putting together a vibrant and happy community.

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1. Hatchetfish

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  • Scientific Name: Gasteropelecidae (family)
  • Other Tank Mates: Corys, Plecos, Tetras
  • Full Size: 1 – 1.4 inches
  • Water Temp: 74 – 83°F
  • Tank Size Required: 30-gallon
  • Care Difficulty: Intermediate

There are a few different varieties of freshwater Hatchetfish, and they all make for peaceful tank mates with Blue Crayfish. These fish like to stick to the top of the tank, so they are not very vulnerable to a bottom-dwelling crustacean – and they can be very fast as well.

They are predatory, and a little challenging to care for, but they are very entertaining when they’re swimming in groups. The Common Hatchetfish is less shy than the Silver variety, and the Marbled perhaps has the most interesting appearance.


  • Top dwellers that will stay away from crayfish
  • Beautiful in shoals


  • Can be shy and become stressed

2. African Butterfly Fish

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  • Scientific Name: Pantodon buchholzi
  • Other Tank Mates: Tetras, Barbs, Plecos
  • Full Size: 4 – 5 inches
  • Water Temp: 73 – 86°F
  • Tank Size Required: 40-gallon
  • Care Difficulty: Advanced

One fish that is very unlikely to feel threatened by your Blue Crayfish is the African Butterfly Fish. These guys are large surface dwellers that are not afraid to defend themselves. They will actually eat small crustaceans in the wild, but Blue Crayfish are too big to become a meal.

African Butterfly Fish have a wonderfully interesting appearance and relatively calm personalities. They can usually be found relaxing at the top of the tank waiting for a meal.


  • Surface-dwelling and large
  • Attractive appearance


  • Have quite particular needs

3. Golden Wonder Killifish

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  • Scientific Name: Aplocheilus lineatus
  • Other Tank Mates: Corys, Dwarf Cichlids, German Blue Rams
  • Full Size: 3 – 4 inches
  • Water Temp: 72 – 77°F
  • Tank Size Required: 20-gallon
  • Care Difficulty: Easy

A particularly glowing color variation of the Striped Panchax, the Golden Wonder Killifish is one of the few of its family that is large enough to not be threatened by a Blue Crayfish. They are also a beautiful shiny gold color, which is what gives them their name.

These fish are fast swimmers that stay at the top of the tank, which means they are rarely going to interact with your Crayfish at all.


  • Attractive appearance
  • Large and fast


  • Will eat smaller fish

4. Red Tail Shark

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  • Scientific Name: Epalzeorhynchos bicolor
  • Other Tank Mates: Tetras, Gouramis, Zebra Danios
  • Full Size: 4 – 6 inches
  • Water Temp: 72 – 79°F
  • Tank Size Required: 50-gallon
  • Care Difficulty: Intermediate

A very striking addition to any tank, the Red Tail Shark is more closely related to a carp than it is to an actual shark. Beyond their obvious aesthetic appeal, they are also active and exciting, and they grow to be the perfect size to be safe from a Blue Crayfish.


  • Striking appearance
  • Large size


  • Require a larger tank

5. Pearl Gourami

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  • Scientific Name: Trichopodus leerii
  • Other Tank Mates: Tetras, Corys, Danios
  • Full Size: 4 – 5 inches
  • Water Temp: 77 – 82°F
  • Tank Size Required: 30-gallon
  • Care Difficulty: Medium

A Pearl Gourami is certainly a very elegant and beautiful fish to look after, and they are easily large enough to avoid becoming a Crayfish meal. They’re not too challenging to care for, but males can be quite aggressive toward other fish and they are a little particular about the tank conditions that they like.


  • Attractive appearance
  • Large and able to defend themselves


  • Can be aggressive to other fish

6. Rainbow Darters

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  • Scientific Name: Etheostoma caeruleum
  • Other Tank Mates: Minnows, Zebra Danios, Loaches
  • Full Size: 2.2 – 2.4 inches
  • Water Temp: 55 – 70°F
  • Tank Size Required: 30-gallon
  • Care Difficulty: Moderate

If you’re looking for a colorful and slightly unique option, Rainbow Darters are very vibrant and exciting. They are not particularly common in home aquariums, but they are relatively easy to care for and are large and fast enough to live happily with a Crayfish.

They also like fast-moving water, which Blue Crayfish tend to be very happy in as well.


  • Reasonable size and fast
  • Live moving water


  • Need lots of decorations, plants, and hiding spaces

7. Guppies

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  • Scientific Name: Poecilia reticulata
  • Other Tank Mates: Tetra, Corys, Rasboras
  • Full Size: 0.6 – 2.4 inches
  • Water Temp: 72 – 82°F
  • Tank Size Required: 10-gallon
  • Care Difficulty: Easy

Is there an aquarium fish that is more iconic than the humble but flamboyant Guppy? Though they might be small enough to occasionally fall prey to a Blue Crayfish, they are very active breeders so you will almost always have an active and expanding group in the tank.

Guppies come in a variety of colors and patterns, which is another reason why they are so charming.


  • Active breeders
  • Easy to care for


  • Small enough to occasionally be caught by a Crayfish

8. Tiger Barbs

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  • Scientific Name: Puntigrus tetrazona
  • Other Tank Mates: Corys, Plecos, Tetras
  • Full Size: 2.5 – 3.5 inches
  • Water Temp: 75 – 82°F
  • Tank Size Required: 20-gallon
  • Care Difficulty: Easy

Tiger Barbs do have a bit of a reputation for nipping the fins of other fish, but this actually means that they are confident and boisterous enough to avoid being harmed by your Blue Crayfish. They are reasonably sized, colorful, and love to show off.


  • Attractive appearance
  • Decent size and will defend themselves


  • Can nip at other fish

9. Zebra Danios

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  • Scientific Name: Danio rerio
  • Other Tank Mates: Corys, Swordtails, Tetras
  • Full Size: 1 – 1.5 inches
  • Water Temp: 70 – 78°F
  • Tank Size Required: 10-gallon
  • Care Difficulty: Easy

Zebra Danios are a favorite in many different community tanks because of their active nature and friendly personalities. They are one of a number of Danio species that can get along with a Blue Crayfish, simply because they are so fast that they are unlikely to get caught.

This particular variety is one of the most active, and they have distinctive stripes that really make them stand out.


  • Fast and active
  • Easy to care for


  • Slightly small so can look like a snack to a crayfish

10. Rose Danios

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  • Scientific Name: Danio roseus
  • Other Tank Mates: Tetras, Mollies, Swordtails
  • Full Size: 1 – 1.5 inches
  • Water Temp: 73 – 77°F
  • Tank Size Required: 15-gallon
  • Care Difficulty: Easy

Another excellent Danio option to add to our list, Rose Danios are also fast-moving and able to keep away from a Blue Crayfish with ease. They have a delicate, pale red coloring that makes them very attractive and they are simple to care for as well.


  • Fast-moving
  • Peaceful and very pretty


  • Small enough to be slightly vulnerable to a Crayfish

11. Rasboras

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  • Scientific Name: Trigonostigma (genus)
  • Other Tank Mates: Tetras, Danios, Barbs
  • Full Size: 1.5 – 2 inches
  • Water Temp: 75 – 80°F
  • Tank Size Required: 10-gallon
  • Care Difficulty: Easy

Although Rasboras are on the smaller side, they are more than fast enough to avoid a Blue Crayfish. There are many different kinds to choose from, but they are all known for being both speedy and easy to look after.


  • Fast-moving
  • Easy to care for


  • Will eat smaller fish

12. White Cloud Minnow

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  • Scientific Name: Tanichthys albonubes
  • Other Tank Mates: Danios, Guppies, Barbs
  • Full Size: 1 – 1.5 inches
  • Water Temp: 64 – 72°F
  • Tank Size Required: 10-gallon
  • Care Difficulty: Easy

With a peaceful personality and beautiful appearance, White Cloud Minnows are a wonderful addition to any tank. They get along well with most other species, and they tend to avoid the areas where your Crayfish spend most of their time.


  • Very similar tank needs to Crayfish
  • Easy to look after


  • Small enough to be vulnerable to Crayfish


So, what do you need to know when you’re trying to choose tank mates for a Blue Crayfish? First, remember that they are probably going to try and grab your fish with their claws at some point, so you either want fish that are fast enough to get out of the way, large enough to be safe, or spend most of their time in another part of the tank.

The other option is choosing small live breeders, which will be giving birth to new fish to make up for the limited few that might get caught.

Ian Sterling

Ian Sterling, founder of, began his aquarium journey over 30 years ago, driven by a deep fascination for fish and their diverse personalities. His website,, is dedicated to making fishkeeping accessible and enjoyable, offering beginner-friendly guidance, expert insights, and a community for aquarists to connect and share experiences.

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