Crayfish – The Care, Feeding and Breeding of Freshwater Crayfish (Crawfish)

crayfishQuick Stats

Minimum Tank Size: 5 Gallons
Care Level: Easy
Water Conditions: PH 6.5-8 and Medium Hard to Very Hard
Temperature: 65-75 F (18-23 C)
Maximum Size: 3 inches (8 centimetres)

Introduction

For anyone looking for a quirky and interesting pet, the freshwater crayfish is an excellent choice.. They are easy to care for, extremely hardy, and often interact with their owners. While crayfish are definitely not safe for a community fish tank, it is well worth having a tank dedicated to crayfish just to enjoy their antics.

When choosing a freshwater crayfish, it’s important to know that there are well over 100 species of crayfish from around the world. While most crayfish require cool water, some require ¬†tropical temperatures to thrive. Before purchasing a crayfish, a owner should do some research to determine the crayfish species needs. If a crayfish is well cared for, they will usually live 2-3 years, with some species living even longer.

Housing

A single crayfish can be kept in a relatively small aquarium. A 5 to 10 gallon aquarium is usually more than adequate, especially if regular water changes are provided. Crayfish are notorious for hiding their food, and will often have a stash hidden away in a cave or flower-pot. On top of that, they are also messy eaters, and when coupled with hidden food , water quality can quickly decline. When doing water changes, you should always check for a stash of food in any of the crayfish hiding spots.

If more than one crayfish is going to be housed in a tank, then a minimum of 20 gallons need to be provided. Crayfish are cannibalistic by nature, and when a crayfish moults it is nearly defenseless until its shell hardens again. During this time, it will hide for a few days, so don’t be too alarmed if a crayfish disappears for a up to a week at a time. Because of this, it is very important to provide numerous hiding places and enough space for each crayfish in the aquarium –¬† unless someone wants their crayfish to become an expensive meal for the other tank inhabitants.

It becomes much trickier when it comes to housing crayfish with fish. There are many accounts of people successfully keeping crayfish and fish together, but given enough time, either the fish or the crayfish is going to be eaten. There is nothing worse than losing a large, expensive fish to a crayfish over the course of a night. Or alternatively, finding crayfish parts scattered across an aquarium, with a very full looking fish. While a person can certainly try to keep fish and crayfish together, it ends badly more often than not.

The filtration for a crayfish should usually be a HOB (Hang-on-back) filter. While a sponge filter is cheaper than an HOB filter, the air line leading out of the tank gives the crayfish a perfect escape route. If you leave the crayfish alone long enough, you will eventually see a crayfish running around on the floor of your fish room.

Feeding

A crayfish’s main diet should be comprised of sinking Shrimp Pellets, but they also enjoy some green vegetables and frozen foods in their diet. They are not picky when it comes to green vegetables and can be offered cabbage leafs, zucchini medallions and shelled peas. As for frozen foods, they happily accept small portions of frozen fish, daphnia, bloods worms and brine shrimp.

A word of warning – crayfish love aquatic plants and will eat any that are put in the tank with them. An adult crayfish can strip a heavily planted aquarium bare in a matter of days. So while it may be a good place to dispose of unwanted plant clippings, you should never put any plants in their aquarium that aren’t replaceable.

crayfishBreeding

Most species of crayfish will breed at any time in the home aquarium, though feeding high quality foods and keeping the water pristine will help trigger breeding behavior. Crayfish can be frustratingly hard to sex for someone new to keeping them, but the easiest way is to look at the swimmerets. The males will have swimmerets that extend past the back legs, while the females won’t have any past the back legs.

When mating begins, the male deposits a sack of sperm on the female who then passes her eggs through the sperm to fertilize them. After the eggs have been fertilized, they are then kept under the tail by the female who should be placed in a tank on her own at this point.

After around four weeks, the eggs will hatch and the young crayfish will emerge. The female crayfish will take care of the young for a short period of time, but should be removed after a few days to prevent the fry from being eaten. A large nursery tank is required if any number of crayfish fry are expected to survive as they are extremely cannibalistic like their parents.

The baby crayfish can be feed blanched cabbage leafs or lettuce leaves, and also consume detritus in the tank. As the crayfish grow, the larger ones should be removed from the tank as they will feed voraciously on the smaller crayfish.

Comments

    • says

      That’s a great tank for them. The hatchlings should be fine with such a large tank, even with the parents still in there. You’ll lost some, but if you provide enough hiding places you should be good to go.

  1. Gene Oser says

    Okay, So I have had craw-fish my whole life, This is the first time I have had them breed and the mom die’s while the eggs are still under her un-hatched. Is there a way to go about keeping them alive? I removed the mom from the tank I used a spoon and gently removed her eggs and put them in a separate Tupperware dish, Is there any other advice you could give me ?

    • says

      Sorry for the delay in getting back to you. The only way that you could possible keep them alive is by using an anti-fungal, but I’ve never known anyone to keep eggs alive after the parent has passed away. That’s not to say that it can’t be done, but beyond trying to keep fungus off of the eggs, I’m not sure what else could be done.

    • says

      Also, just as another note, they should be kept in a full aquarium if at all possible. If they hatch in the tupperware, the water quality would quickly crash, and it would be very difficult to feed them in there.

  2. bradley says

    I have a fresh water lobster in my tank and for the first time he seems to be stiff and not moving and basically laying on his side.iv never seen this behaviour before and wondered what its from . If hes dying or ready to shed his skin. My other 2 lobsters are still healthy and active

    • says

      How long has it been laying on its side? During moulting, they may lie on their side for short periods of time while they shed. If it’s been more than a short while, then it sounds like it might be illness. I would consider checking your water parameters. Also, is your crayfish getting any iodine in its diet? Shrimp pellets and algae wafers are generally good sources of iodine which are very important for crayfish.

      • bradley says

        i feed them nutrafin max bottom feeder pellets and a piece of hake every few days, He has been on his side for about 20 min , i will check the water parameters as you said to evaluate the next step

  3. Emma says

    I was just wandering if all crayfish sexing is the same. I have 3 freshwater crayfish at home and have no idea how to tell because if it is all the same are males more rare than femles?

    • says

      As far as I know, all of the popular species of crayfish are sexed in the same way (though with the sheer number of species out there, I could be wrong). But the easiest way to tell is to look for the claspers on the male. I found this picture which makes it easy to see the difference.

  4. Tavia says

    I have a blue crayfish that seems to have babies attached to her. I have her in a 10 gallon tank with 4 small tropical fish. How do I help them survive? do I put in a tank divider? Do I need t separate her from the hatchings?

    • says

      A divided would work for now, and leave the hatchlings on her until they let go on their own. Once they let go of the mother, the mother can be removed. The problems come later when the crayfish hatchlings start to mature. They are very cannibalistic, and you will have very high mortality if they are kept together. Most people who try to breed crayfish have numerous tanks to split up the hatchlings.

  5. vanessa says

    Ok we just got our first crayfish and we are a little concerned with the tank. It is a 3 gallon tank with a huge rock. No lid on the top but water is not even half way up the tank. Any help would be great

    • says

      Sorry about the delay in getting back to you, but that tank should be fine as long as you keep on your cleaning schedule. Also make sure that your crayfish isn’t hording food, or that will quickly foul your water. I would recommended getting a lid if you can though, so you can fill the tank with more water.

  6. mark sagusti says

    we have a blue crayfish and the egg are all black but dose not seem to be growing. its been 4 days and how long dose it take to hatch ?

    • says

      Sorry about the delay in getting back to you, but eggs take a minimum of four weeks to hatch. And that’s only for warm water species. Cold water crayfish can have eggs on them for as long as six weeks. Hope this helps.

  7. Kevin says

    I was considering getting an orange dwarf crayfish for my. 10g. Most websites I have read say that they are fairly peaceful and can be kept in a community tank,. I have read some reports of them eating fish though. What should I think?
    Thanks

    • says

      I actually did an article on dwarf crayfish recently. You can check it out here.

      But in my experience, they are the only crayfish that can generally be kept safely in a community tank. With that being said, there is always some danger in keeping crayfish with fish. They will eat anything that they can, and if a fish is sick, or they just get an opportunity, they will try to eat the fish. This is much more rare with dwarf crayfish, but it is still known to happen in rare instances. So always proceed with caution.

      Also, you will still have to provide hiding places for the crayfish during molting, as fish will be more than happy to eat a small, vulnerable crayfish.

    • Anonymus says

      @ Kevin….

      I’ve had the same problem but with my Red Crystal shrimps and I managed to hatch the eggs with no problem.

      What you can do after you collect the eggs:
      – put them in a fish net(the one used to catch the fish in your aquarium) and put in in front of the output spray bar if you have a canister filter
      -put them in a breeding net and place the net under the output of your HOB filter.

      I had a canister filter and I used a fish net in front of the output spray bar to keep the eggs moving and aerated

      Good luck.

  8. Venessa says

    i just recently got a crayfish and bought shrimp pellets and was wondering how often should we feed him every website states what you should feed them but not how much

    • says

      Usually one or two small pellets is more than enough. I’ve read some estimates that they only need to eat about 5% of their body weight a day, so try to judge the amount of food based on that. Also, always check their cave during weekly cleanings, since they are known to horde food, and it can accumulate in their and foul the water.

  9. Kimberly says

    I just got an Australian Blue Lobster and I was wondering if I needed to put in some sort of bubble making machine? And how much I could fill my 10g tank upto?

    • says

      You don’t necessarily need a bubbler, but you should have some type of filter on the tank. I tend to use sponge filters, but just make sure that they can’t climb up the air line going into the tank. Also, you can filter the tank to within about two inches of the top with no problem. Just make sure that you give the crayfish a chance to acclimatize to the new environment, if it’s not currently fully submerged in water. This can be done by creating an environment where he can submerge or stay above the water if it chooses to at first.

    • says

      It’s best not to take it out unless you have to. You can cause problems for it if air bubbles become trapped in the gills. You’ll need to re-acclimatize it to water again, by placing it in a bucket where the water isn’t over its head for a least 24 hours, and then hold it upside in the tank to get rid of the last bubbles.

  10. Mark says

    I keep crayfish together with fish and they breed regularly. The orange ones, I find are the most passive. The blue and white ones sometimes have a go at each other but will usually only take a pincer off. They very rarely catch a fish, even at night, because they are relatively slow moving. If a fish is sick they will eat it. But healthy fish are usually safe.

    • says

      The dwarf crayfish I find are quite good with fish, and I’ve had limited success with electric blue crayfish. But I’ve also seen some that terrorize the tank. The only ones that I’ve never had any luck with are the red North American varieties. The few times I’ve risked keeping them with fish, it’s been nothing short of a chain saw massacre the minute the lights went out at night.

  11. Mark says

    My larger fish even share wooden barrel hiding places tgether with crayfish and I havent lost one yet. Crayfish can also be trained to take the pellet from your fingers if you have enough patience and it impresses guests no end

    • says

      One of the best ways to improve a crayfish’s colour is through lighting. Assuming that you are feeding it a high quality food (spirulina, sinking pellets and vegetables), and keeping the water as clean as possible, you should add a fluorescent light to the tank. Many crayfish will become dull under an incandescent light, but a fluorescent light that mimics natural light can improve their colouring considerably.

  12. Rasmus Christensen says

    Hey. we just got ourselves a red clarkii crayfish and it is really a fun and cool animal. We were wondering if it would make any sense to feed it with living bait, maybe a scrimp or clam?

    • says

      They definitely appreciate live food in their diet, and ghost shrimp are a good, cheap option to feed them. With that being said, depending on the size of the crayfish and the tank, they may have trouble catching the shrimp. As for the clam, I don’t know if they’d be able to eat it. But even if they do find a way to get at it, most clams would be too large to fully eat, and the leftovers would really foul the water. I would stick to live food, and maybe even try other aquarium staples like blackworms that are easy to obtain and feed.

      • Rasmus Christensen says

        Thanks a lot Matthew. We have a 7 gallon tank, and it is about 8 cm long. It is pretty active and fast, but so are the shrimp I gues. I gues that we could try and bring a ghost shrimp home, and take it up again if it isn’t a succes.

        Thanks for this awesome website and forum. We have learned a lot from it.

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