Crayfish are very pretty to look at – like little lobsters wandering around your aquarium.
Unfortunately, they’re not exactly known for getting along well with fish that would normally go into a community tank.
The best tank mates for crayfish are hatchetfish, zebra danios, giant danios, furcata rainbowfish, and other fast, surface dwelling fish that rarely go into the lower parts of the aquarium. Fish that sleep near the bottom of the tank will get eaten by crayfish and thus don’t make good tank mates.
I’ve compiled a list of all of the fish that have the best chance at surviving in a tank with a crayfish. Do keep in mind, however, that any fish is likely to get eaten at some point and therefore is at risk.
(You may be able to increase the odds of your fish surviving by making sure your crayfish has plenty of easily available food nearby at night when it comes out to hunt.)
These are just the ones with the best chance at survival in a crayfish’s territory. Stay tuned for the end of the article where I cover types of crayfish that are far less likely to kill fish.
The hatchetfish is probably the best candidate for surviving in a tank with a crayfish.
As a surface dwelling fish that almost never goes down to the bottom of the tank, it has a better chance at not being eaten than most other fish that you could add to the aquarium.
It’s also a unique looking fish that will add interest to your aquarium.
The downside to hatchetfish is that they only eat food they find floating on the surface. If it sinks down into the middle of the aquarium, they won’t eat it. Because of this, you need food that will float for a long time to avoid starving them.
Important to the survival of your hatchetfish is to not have any tall plants or decorations at the bottom of your aquarium. Crayfish are known to climb plants to reach fish they otherwise wouldn’t be able to catch.
White Cloud Mountain Minnows
White cloud mountain minnows are an interesting looking white fish that was one of the early fish to become popular in the hobby. (Now largely overshadowed by neon tetras and other similar fish.)
They like aquarium temperatures on the cooler side, and they can be pretty hardy if you avoid buying the feeder variety.
They’re relatively quick fish, so the chances of them being caught is a bit lower than some other fish – especially if you make sure your crayfish has easier items on the menu.
If some do get caught, WCMM are pretty cheap, so you won’t be out a lot of money to replace them. Morbid, but that’s the risk if you want to keep fish and crayfish together.
Zebra danios are another species of fish that look good and are pretty quick – making them less likely to be grabbed by a crayfish.
In my aquarium, they typically stay around the top of the aquarium, though they do occasionally venture farther down towards the bottom. (Into the danger zone.)
They like a bit colder water, but they are easy to take care of and will eat any basic flake food.
If you want flashy, colorful fish, they come in glofish varieties as well – so you can get danios in colors that will complement your crayfish’s colors.
Silver dollars are a type of fish that is often used as a dither fish in an aquarium with larger, more aggressive fish. (Such as some cichlids.)
They are a fast and somewhat flighty fish that likes to shoal in large numbers.
They also get quite big – up to 6″ long when they’re fully grown.
Because of all of this, they stand a larger chance of surviving in an aquarium with a crayfish.
Giant danios are a bit less common in the hobby, but they can still be relatively easy to find. Like zebra danios, they are a fast swimmer.
As their name suggests, they get a lot bigger than regular danios – around 4-6″ fully grown.
The fact that they are both big and fast gives them a slight advantage in surviving in an aquarium with a crayfish.
They also have quite interesting coloration, so if you have at least a 30 gallon aquarium, you might want to check them out.
Tiger barbs are an interesting looking – and somewhat aggressive – community fish that aquarists have had mixed results with in crayfish tanks.
A lot of fishkeepers have had great luck and haven’t lost any of their tiger barbs to crayfish attacks.
A few, however, have had their populations decimated while they slept.
Common advice I’ve seen indicates that you’ll have better luck if you make sure your crayfish is well fed and doesn’t have any reason to hunt your barbs. Crayfish are opportunistic feeders, so if you make sure they have easier options, they’re less likely to go after your fish.
If you’re willing to take the risk, tiger barbs may be a good choice for your aquarium. Glofish also makes a deep red variation that – in my opinion – looks much better than the standard tiger barb.
Bala sharks are another fish that may work in an aquarium with a crayfish.
They get big, are somewhat aggressive, and are fairly fast swimmers, so they may be able to avoid being grabbed.
Unfortunately, they require a much bigger aquarium than most people think. A lot of people get them home, throw them in a 10 or 20 gallon tank, and don’t figure out their mistake until it’s too late.
Bala sharks get big – with an adult size maxing out around 14 inches – and require an aquarium that’s at least 5-6′ long and a minimum tank size of 120 gallons or more.
At full size, I doubt they have much to worry about from crayfish, but the equipment to house them is quite expensive, so I wouldn’t get one just to throw in an aquarium with a crayfish if you don’t already have the right setup.
Neon tetras really need no introduction. They are one of the (if not THE) most popular fish in the hobby, and they are available everywhere you can get freshwater fish.
They are not the hardiest of fish (being prone to neon tetra disease), but they are cheap and a relatively quick schooling fish.
If you’re looking for a good fish to test out whether or not you want to keep fish with your crayfish, neon tetras would be a good starter fish.
I’ve heard from a few crayfish owners that have had good luck with them, and if a few get eaten you won’t be out a lot of money.
The dwarf mosquitofish – also known as the least killifish – is a small predatory fish that lives near the top of your aquarium.
Because of this, they have an advantage in surviving in a tank with a fish eating monster lurking at the bottom.
They can be a bit harder to feed – since they are a micropredator – but if you’re willing to put in the effort to take care of them properly, they can be a good option for your aquarium.
(By the way, they get their name because they’re often put into ponds to eat mosquito larvae.)
Wrestling halfbeaks are an odd looking type of livebearer that lives at the top of aquariums. Like the dwarf mosquitofish above, this makes them better choices for aquariums with crayfish.
Being livebearers, they will also repopulate, meaning they will naturally replace any fish that get eaten by your crayfish.
They get the “wrestling” part of their name because the males will fight each other to decide who gets the affections of your female halfbeaks. They don’t usually injure each other, so this behavior just adds more interest into your aquarium.
You’ll want to feed them live food if possible – blood worms and wingless fruit flies being favorites.
Golden Wonder Killifish (AKA Golden Panchax)
As its name suggests, the golden wonder killifish is a striking gold fish that will look great in your aquarium. (The image above is a normal striped panchax, which is the same species just a different color variation.)
Like the least killifish, they are micro-predators and should be fed live foods if possible. Some of them may be able to be trained to eat flake foods (depending on what they were fed by the breeder), but this isn’t something you should count on.
Because they have a tendency to stay at the top of your aquarium, they are less likely to get caught out by your crayfish.
They do like plants, however, so you’ll want to consider maybe some floating plants with roots that hang down into the water or plants that suction cup onto the walls of your aquarium to make it harder for your crayfish to climb them.
The furcata rainbowfish is an interesting looking fish with yellow fins and blue eyes that would make a great addition to an aquarium.
They do typically inhabit the middle and upper sections of the aquarium, but this doesn’t mean that they never go into the bottom.
Because of this, while they may be less likely to stray into the range of your crayfish, it’s not a 100% thing.
If you use one of the more peaceful types of crayfish listed below, however, this should definitely be a type of fish to consider for your aquarium.
The last item on this list is the brown pencil fish. Like quite a few of the items on this list, they tend to stay towards the top of your aquarium. Unlike most fish, however, you’ll often find them pointing upwards at an angle towards the surface of the aquarium.
They will eat flake foods – unlike a lot of the killifish – but like the other surface dwelling fish, they will happily accept offerings of live foods as well.
Tubifex, daphnia, and other live foods that move around on the surface will be quickly eaten.
This fish may not be the best looking fish of the bunch, but if you want to add a bit of interest to your aquarium, this may be the fish for you.
The Best Crayfish for Community Tanks
Now that we’re done talking about fish, let’s talk about which type of crayfish is least likely to kill your fish.
Most crayfish will eat fish as a preference – not caring whether they are live or dead. There is one type of crayfish, however, that prefers eating plant matter and will very rarely hunt fish.
That crayfish is the marbled crayfish, also known as the marmokreb crayfish.
That’s not to say that this crayfish is completely fish safe, but if you want a crayfish in your community tank, this is absolutely your best bet.
What’s more, it will change color depending on what you feed it. Feeding it food with more green pigmentation will cause it to turn more green. Feeding it food with a lot of bright red pigment will cause it to turn bright red.
There is a downside, however. This crayfish is also known as the self-cloning crayfish, and exactly like it sounds, it will quickly reproduce in your aquarium.
Luckily, most stores will accept donations of fish and invertebrates, so you can bag up any extras and drop them off at your local fish store.
Another type of crayfish that will work better than most in a community tank is the mexican dwarf crayfish. It is smaller, less likely to attack fish, and generally a better roommate than the blue crayfish and other similar options.
I wouldn’t put it in with any of the larger fish on this list, especially the bala shark, but other than that it may be a better option for your aquarium.
If you just want something that looks like a lobster and aren’t sold on a crayfish specifically, you might want to look into the vampire shrimp. It’s a completely peaceful filter feeder that looks like a crayfish and won’t attack anything else in your aquarium.
With all of the fish on this list and all of the types of fish-friendly crayfish, you can definitely make a community tank work with a crayfish.
That’s not to say that it will be easy or that you will never have any fish come up missing, but you should be able to find a setup that looks amazing and works for you.