Dwarf crayfish are small cousins of big crayfish species like the blue Procambarus alleni. Unlike most other crayfish they are peaceful and suitable for some types of community tanks. They belong to the genus Cambarellus, which contains quite a few different species, all with similar requirements. The most commonly known and kept orange CPO (orange dwarf crayfish) is one of them.
Keep reading for everything you need to know about dwarf crayfish and keeping them in your own aquarium!
|Minimum tank size||8 gal (30 L)|
Cambarellus genus of dwarf crayfish, containing:
Cambarellus patzcuarensis Orange (CPO/orange dwarf crayfish/Mexican dwarf crayfish), Cambarellus shufeldtii (Cajun dwarf crayfish), Cambarellus montezumae, Cambarellus ninae, etc.
Dwarf crayfish natural habitat:
Dwarf crayfish are mainly found in Mexico and southern parts of the USA. Their primary habitat consists of lakes, small streams and slow-flowing rivers.
Dwarf cray fish appearance:
Dwarf crayfish are freshwater crustaceans that look somewhat like a tiny version of lobsters. Most wild varieties have a brown-greyish color with darker stripes that allows them to blend in with the environment. A slight hint of blue or orange is also sometimes seen, but is usually limited to the pincers. Females will sometimes carry eggs between their back legs.
Several varieties of Cambarellus have been selectively bred for color. Cambarellus patzcuarensis ‘Orange’ (orange dwarf crayfish), for example, features bright orange coloration. Cambarellus texanus ‘Blue’, on the other hand, is appreciated for its splotchy but bright blue carapace.
If you find a strange, empty crayfish-shaped shell in your aquarium there is no need to worry. Your dwarf crayfish hasn’t died, it has molted!
Dwarf crayfish requirements:
Dwarf crayfish are relatively undemanding when it comes to tank size and water values. Couples/trios of almost all of them do fine in a tank of at least around 15.5″/40cm. Trios of the smallest types, like Cambarellus shufeldtii (Cajun dwarf crayfish), can even be kept in 12″/30cm aquariums as long as there are multiple hiding places for every one of them.
Heavy filtration isn’t necessary, but at least a small filter is required to allow the tank to cycle and remove particles. Never introduce dwarf crayfish into an uncycled aquarium! They don’t react well to nitrites and ammonia. For more information on how to cycle an aquarium, check out this article.
Dwarf crayfish love to hide, so lots of hiding spots are definitely necessary to prevent stress and territorial battles. Plants, wood and piles of rocks are all great options and they will especially love a shrimp flat. Hides are extra important when a crayfish has just molted, as it will be very vulnerable for the first few hours.
Dwarf crayfish tankmates:
When it comes tank mates, dwarf crayfish don’t limit your options like their bigger cousins do. They are quite peaceful and not really known to kill fish at all. This makes them safe to keep with pretty much any community species that aren’t large enough to have an appetite for small crustaceans.
Small snails, baby shrimp and bamboo shrimp may be damaged by dwarf crayfish, but apart from that they’re usually harmless and will fit into most community tanks that don’t contain larger, hungry fish.
Due to their size, dwarf crayfish make a great option for nano aquariums. Tanks between 5-10 gallons don’t give you many options when it comes to stocking, as most fish simply grow too large. If you still want plenty of activity in your small aquarium, the genus Cambarellus makes the perfect choice.
Dwarf crayfish diet:
These crayfish are omnivores and will eat pretty much anything. I feed mine Hikari Crab Cuisine as a staple (I wrote a review of it a while ago for everyone who is considering buying it), along with all kinds of other foods.
Frozen blood worms/black mosquito larvae, pieces of algae pellet, peas, and even homemade gel foods will all be appreciated. Their varied diet makes dwarf crays a great addition to your aquarium cleaning crew.
In order to provide your dwarf crayfish with a constant source of snacking you can consider adding any kind of leaf litter. Not only are these dried leaves beneficial to your water quality: crayfish will also eat them when they start breaking down. You can read more about Indian almond leaves here. All kinds of leaf litter will work, though.
Dwarf crayfish behavior:
If you’re interested in keeping shrimp but think they’re a bit too boring for you, you might want to consider one of the many dwarf crayfish species. They show much more personality towards each other and even towards you. They can often be observed carefully approaching each other and suddenly making a huge jump backwards when one of them gets too close.
When you approach the aquarium, you’ll often see them running towards you, pincers raised, ready to defend their territory – seemingly forgetting how small they are. Quite adorable!
Breeding dwarf crayfish:
Breeding dwarf crayfish is not too difficult and actually quite similar to breeding dwarf shrimp. After the mating process, eggs will develop under the female’s back legs (swimmerettes). You’ll see her carefully tending to these throughout the ‘pregnancy’, waving water over them and occasionally even cleaning them.
If the eggs are dark colored, they are fertilized and will hatch into tiny copies of the parents in around 3-4 weeks. The fry will stay with the mother for a short while (up to a few days), still hiding between the swimmerettes. After this they slowly venture out into the world.
The fry will eat leftover food, rotting plant bits and, occasionally, each other. Be sure to provide extra hiding places for a high survival rate. Don’t worry if you don’t see any of them for the first few weeks. I often suspected all my baby crays had died until suddenly a few surviving juveniles emerged from their hides!
Buying dwarf crayfish:
When buying dwarf crayfish, look for healthy specimens with bright colors that appear active. Missing legs can regrow with the next molt and are not a huge problem. You can buy orange dwarf crayfish (CPO) online here!
I’d definitely recommend dwarf crayfish to anyone who’s looking for a new, fun aquarium challenge. They don’t require large tanks or very specific care and won’t destroy plants, which makes them a great choice for beginners and more experienced aquarists alike.
If you think I forgot to mention something in this caresheet or if you have more questions about keeping dwarf crayfish, be sure to leave a comment below. Happy invert-keeping!
131 thoughts on “Caresheet: Dwarf Crayfish (Cambarellus Genus)”
Hi Mari, thanks for the informative post! Quick question, I’ve got 3 Orange Mexican Dwarf Crayfishes, but am looking at maybe adding 2 more Blue Brazo Mexican dwarf crayfish in the same tank. Can they interbreed? Can’t seem to find a definitive answer on this online. Thanks in advance!
If you’re talking about orange dwarf Mexican crayfish (Cambarellus patzcuarensis) and blue brazos dwarf Mexican crayfish (Cambarellus texanus), then yes, they have the ability to interbreed. Organisms from the same genus (Cambarellus) are generally able to breed but often result in mutated hybrids.
I would only keep one species in the tank to be safe!
I caught my two male orange Mexican crayfish trying to breed . Well, one was and the other was helping pin the female down.the question is, is there a ratio of male female I should keep? I broke them up because I thought they’re going to kill her or were killing her. My other female has eggs in my hospital tank so it’s 2 male to the one female for now.
The two males could become a problem if they’re both trying to breed with her constantly; it’s also been noticed that males are much more likely to be aggressive to their own species than females, and this aggression can change over time. For the time being, I would maybe add more hiding spots or even divide the hospital tank into two and place the other female in there, waiting to reintroduce her along with the other one.
There isn’t really a correct ratio for these crayfish, but it might be worthwhile to add more females down the line or think about rehoming one of the males.
I hope this helps. Keep us updated!
In what temperature dwarf crayfish can stay alive ? For example below 10 Celsius is ok. Thank you!!!
Dwarf crayfish do best around 60°–75° F (15.6° – 23.9° C) with right in the middle being most preferred. 10° C is way too low and can cause your crayfish to go into hibernation and/or death.
Can I keep 4 in a 10/ 12 gallon with lots of hides and no other fish or snails?
To be on the safe side, I would only keep maybe 2-3 dwarf crayfish in a 10/12 gallon tank. In general, the more hides the better!
Let us know how it goes.
Will they be okay with african dwarf frogs
I honestly don’t think dwarf crayfish would get along with African dwarf frogs too well, especially if you have a smaller tank. There’s just too much that could go wrong with possibly getting an aggressive crayfish or a frog that is difficult to feed. In general, both these animals are recommended to be kept in species-only tanks, and it’s for good reason!
Thank you so much
If I wanted to keep only crayfish in a tank, what’s the smallest size? Would one or two dwarf be okay in a 2.5 or 3 gallon tank?
Hello! As mentioned in this article the minimum is 30 cm which comes down to about 5 gallons, and that’s for the smallest dwarf crays like shufeldtii. The most common dwarf, patzcuarensis, is better for 8 gallons and up in my opinion.
Be careful, they are very territorial, if you have a small tank with no hidding places, male and female can kill each other. A lot of people had this problem, sometimes it’s only a missing claw, sometimes it’s more serious.
Yup, that’s one of the reasons I recommend both a larger aquarium and plenty of hiding places in the caresheet! 🙂
Got a CPO about 2 weeks back and stuck him in the 10g shrimp tank. He hilarious and fun to watch. The shrimp just ignore him for the most part and he has all but given up on trying to catch them but before that goes wrong I’m planning on setting up a separate tank for him and adding a female with some cherry barbs. The tank I’m going to use doesn’t have a lid, any experience with them climbing out the tanks and going for walks?
Good to hear he’s doing well! I always kept mine with shrimp, they never did manage to catch any judging from the speed at which the shrimp colonies expanded. As for climbing out of the tanks, yes. Your tank should ideally have a tight fitting lid. If not then you might be able to get away with it if you make sure the water level is relatively low, but I’d keep an eye on them regardless, at least until you’re sure they’re not able to Mission Impossible their way out of there.
Good luck and enjoy!
Thanks for the advice. Will make some adjustments. Your caresheets are all very helpful, thanks for that too.
How would this crawfish do in a 50 gallon aquarium with an eastern painted turtle about the size of a U.S. quarter?
Sorry about the late reply. No, that would not be a good idea at all. Turtles eat crayfish unfortunately.
Can i do 2 dwarfs in a 7 gal planted? One orange and another blue?
It depends on which species of ‘orange’ and ‘blue’ crayfish you mean. Would you be able to get their common/species names so I can tell you the exact tank setup that would be best?
I want a pair of Mexican Dwarf Orange Puffer and I want to know if they are compatible in a 10 gallon tank with several guppies .
Sorry not puffer , I mean Dwarf Orange Mexican Crayfish, I wrote Puffer by accident.
I figured the “puffer” part was a typo, no worries! Yes, they are compatible with guppies. 10 gallons is a little on the small side to keep guppies in, though – you might want to reconsider that eventually 🙂
Uhh… I have to disagree with the guppies, because I tried that combination. The CPO mauled my guppies’ tails.
Wow, thanks for the heads up, that surprises me. In my experience the little guys have been uninterested as well as too slow to get a hold of any tankmates.
Hi, I have an 8.8 gal aquarium and was wondering if i get crayfish what species and how many?
Hi! Yes, I keep my dwarf crayfish in an 8 gallon and that works very well. You can get any type of dwarf crayfish – Cambarellus patzcuarensis ‘Orange’ is the most popular due to its bright orange color. You can get a male/female pair or even a trio with two females and one male, that should work well and even result in some offspring! 🙂
hi, I currently have a 10 gal with 5 zebra danio and 2 pygmy cory catfish and getting a mystery snail. I was wondering if it would be suitable to add 2-4 dwarf crayfish. I also have an empty 20 gal that I am planning on setting up soon. or would it be better to wait and set up the 20 gal
Hi! I’d wait until you set up the 20 gal because your stock in the 10 gal right now is not ideal as is. Those zebra danios (caresheet here belong in a larger tank, so if you can move them to the 20 that would be great. The mystery snail also needs to go into the 20 because a 10 is too small to handle its bioload. The school of Cories (caresheet here needs to be expanded to at least 8. Once the danios have been moved and the school has been expanded you can then consider looking into a pair of dwarf crays.
I hope that clears it up. Good luck!
I have a planted 75 gallon tank with a built in refugium. The refugium has a big HOB filter, several chambers of lava rock with plants, then back into the main tank. In the main tank, I have pea gravel, lots of plants, and driftwood. I mainly have guppies, tetras and danios. All small peaceful fish. I was thinking about getting a dwarf Mexican crayfish. Would they get along well in this environment? What is a good number to have? Thank you!
Hi! A few CPO’s should do just fine in a tank like that as far as I can see. You could start with a trio to see how they do 🙂
I really am enjoying my Dwarf Mexican Crayfish. The tank is setup in the school I work at and the kids are doing a whole lesson on them. And they are going to get to name them. I am keeping them in a hi tech tank with CO2… is anyone else doing this? I am worried about the PH swinging from day to night.
That sounds fun! And I think the crays should be fine with the Co2 as long as the swings aren’t too drastic.
Hi I really need some help my crayfish appears to have fungus on him, it’s a white cloudy haze. How do I treat that?
Hi. How is your crayfish doing now? Are you sure it’s a fungus? It could also be something called protozoan fouling, which means the crayfish is covered in tiny organisms. It’s pretty harmless in itself but it’s an indicator of bad water quality or can point to your crayfish not feeling too well. Have you tested the water/do you do regular water changes?
Hey! I was thinking about using an old betta tank (5 gallons) to make a planted tank, and was wondering if I could add a few dwarf crayfish? What type(s) would you recommend if so?
Hi! I think that would be possible. It’s probably best to go for the absolute smallest species, like Cambarellus shufeldtii and diminutus. The more common CPO grows slightly larger and is probably a bit less suitable. Good luck 🙂
Cpo and kuhli loaches? Is it possible?
I think so 🙂 if your tank is at least ~20 gallons I think they should be fine. CPO’s are really peaceful and should leave the Kuhlis alone.
Hi, very informative article.
I have a very concerning situation with my female berried crayfish. She has been shy inside her cave so i provide small piece of algea wafer close to the entrance, all seems normal. I had a new plant (forgot the name) in quaranteen after buying from shop, and decided to add to the aquarium when it was rinsed and ready at night. Next morning I found out that it shed all over my tank, thus i tried my best to scoop the leaves all over the place. I changes 50% of water and added aqua clear solution because it was partially cloudy due to the shedding (already afternoon). Unfortunately, later at nigh I noticed a very strange behaviour from the female cray..she staggers while she walk, like limping and rapidly dash backwards a few rimes..I couldn’t find out why.
Next morning, she seemed very week and close to death. I’m very worried.
My assumption was, would it be because of the plant I introduced and the water changes it caused?
Hi! So sorry to hear about your crayfish. It could be that the plant bits rotted and caused bad water quality. Did you remember to dechlorinate the water (if chlorine is used in your tap water?). It might also be a failing molt. In any case, test your water for the presence of ammonia and nitrites if you haven’t already. If it’s all where it should be (0ppm) I would try to leave her alone for a bit; not much more you can do.
Good luck, I hope she recovers!
I am planning on having some CPO’s. I’ve read from various places that they are quite picky on the water TDS levels. But I am not sure if actually means the bare TDS values including the stuff that affects gH values. Or just the other junk that builds up into water when time passes.
Since quite high gH (100-500ppm) is usually recommended for CPO’s and same range is recommended for TDS as well, I would think that the notes regarding TDS mean that water with high gH is good as long as it is kept quite pure otherwise?
Do you have an opinion on this? Do you just do scheduled water changes or do you have any hard limits regarding water quality?
My tap water has TDS 100ppm with 3.5 degrees gH and I am planning to increase the gH into 7 at water change, so I guess my TDS will be bit less than 200ppm to begin with.
Hi! I actually never payed much attention to the specific water values, although I had Cambarellus shufeldtii instead of CPO’s. As long as pH, gH and kH are relatively high (and stable!) you’re probably fine. I haven’t read up much on their TDS requirements but your thinking here seems correct.
I’ve found that CPO don’t really care about hardness or TDS; they were living happily and breeding both in crystal clear tap water (gH 100-150 ppm (varies from week to week)) and a Badis breeding tank that was full of indian almond leaves and nearly black. (gH 0-50)
Thanks for your input! As I mentioned in my reply I never paid that much attention to it either and I never had any trouble. I’ve read CPO’s CAN be pretty fragile due to selective breeding in which case higher gH would probably be better. If you’ve gotten hold of some less fragile ones I think anything goes, though, haha.
Hello, found your site – really like it and the useful tips and info – great work!
as i was looking to find out which crayfish my son bought in a petstore – it first seemed that it was a cpo – but i think as it is quite big and looks like this one in the picture – http://guppies-r-us.com/uploads/3/5/8/7/3587691/1305295_orig.jpg?217
is it an orange crayfish/tangerine lobster ?
– also ate already 3 fish in 4 days (3 guppies, one betta) – should it be alone in the tank are maybe only with another one
(60 l tank) ? any advice you can give?
thanks in advance !
Hello! Glad you found the site useful!
There are several orange crayfish species (such as Procambarus clarkii ‘orange’, Procambarus alleni ‘neon red’) so determining the exact type is difficult. However, if your cray is not a dwarf type, it should definitely have a tank to itself as they will destroy any (living) thing that crosses their path. I would move yours to a cycled tank (80L is preferable, but 60L should work for now) with no tankmates so it can live by itself without damaging anything.
thank you for your answer! would you recommend adding another one orange/neon red or should they live on their own ? any big/ger fish that will do fine and won’t be catched and eaten by the crayfish?
Nope, I’d definitely recommend keeping it on its own!
Another question….sorry I didn’t think of it before and add it to my last email. I have heard that it is good to add 1/2 dose Kents iodine to my cray tank for molting ease. I asked the breeder I got my crays from and they said they do not reccommend it at all. My crays have sucessfully molted several times. I use Salty Shrimp minerals (I wonder if they put iodine in this to help shrimp molt?) in my water for my shrimps health and feed a calcium fortified food for my shrimp and crays as well. I also feed sea weed on ocassion (when I remember) around once a month. What do you think? Again thank you for this very informative site. So happy to have someone to ask questions of, that actually knows about dwarf CPO’s!
Really enjoyed reading all the information. I just got my 1st pair of CPO crayfish 4 months ago. They are living with my cherry shrimp. I enjoy them very much. They are easier to see than the shrimp and I love when they come to the front of the tank to beg for food. My male is kind of rough on the female when they mate. He tore off 3 claws one time so she has been separated from him for a month. She lost the 1st eggs after about 3 weeks. Hoping to have babies some day. I have heard that having more females than males is better. Do you agree?
Glad to hear the article was helpful for you and you’re enjoying your new crayfish! If you’re noticing the male being too rough on the female, you could definitely go for a second female as long as the tank is large enough. As for the questions from your other comment, I have no experience with dosing iodine in crayfish tanks, but I don’t think it’s necessary. I just fed a calcium fortified food and that seemed good enough.
Good luck! 🙂
I have a very strange situation.. I had three CPO crayfish. 2 female, 1 male in a 15gal tank with a single male guppy. They were living happily together… And I fed the crayfish about 3 little hilarious crab cruising sticks a day (total) and kept the water clean (with all 0s cept ~20ppm for nitrate) with weekly water changes.
One went missing for about a week and I found it yesterday pretty much decomposed under a seashell when doing the water change. Today, the male crayfish which was chilling on an artificial plant… Died as well… On the plant still… I can tell it’s dead because normally he’s really active and he has the dead look.
I’m really starting to get worried because gee, if everything is good… Why are they dying… My temperature is about 78 to 80 F and maybe the only concerning factor is that my tap water is pretty high in pH… (Around 8.2) I know that is probably too high for them to breed but I didn’t think it would cause them to die. :/
Can anyone help me understand what could possibly have gone wrong?
Sorry I meant hikari not hilarious. Silly autocorrect.
Wow, so sorry to hear about your crayfish not doing well! It does sound like you have everything under control so figuring out what’s going on is pretty difficult. The pH is not the problem, they should do fine at 8.2. The temperatures are a bit high but I don’t think that should be too much of a problem either. The only thing I can maybe think of is a calcium deficiency (which is also unlikely because you’re feeding them specialized invert food) or some kind of disease that is affecting all of them. That’s all I can make of it right now, sorry! You seem to be doing everything right so it’s probably not care related.
Did you check your water parameters? Ammonia, nitrate, nitrite? Is your aquarium new? Did you add anything like a new plant? I have had deaths related to new additions. I now try to quarentine everything before adding to my aquariums.
They did check their water parameters, though your point about new additions is indeed something to look into!
Hello,i was wondering if a cute little dwarf crawfish would fit in well with my 4 neon tetra and one yellow(one eyed but well loved)glow fish in there 10 gallon tank?
If so what would you recommend in I feed him so that he gets his food without worry of the other fish eating his food before he can?
Hi! These fish can be combined but unfortunately neither neon tetra nor glowfish are suitable for a 10 gallon. They’re much too active. 4 tetra is also not enough to form a school. I would focus on upgrading and expanding your current stock first! 🙂
Hi there! I just started aquarium keeping a year ago and I’m loving it! I have a 20 liter tank with two male guppies, 1 albino corydora (I know they are supposed to live in groups but the local petstore told me they are fine on their own. So I bought it without knowing unfortunately ) and 5 amano shrimp. I recently found out about orange dwarf crayfish. I was wondering if 1 dwarf crayfish would fit in my tank together with the previously mentioned animals? Or would that be too much? Thanks!
Hi! Unfortunately you were very wrongly informed at the store. Your tank is too small to keep any fish in, so please return the guppies and Corydoras as soon as possible. After that, yes you can keep dwarf crayfish in the tank but try going for one of the smallest species like Cambarellus shufeldtii. Good luck!
Hi! Would a dwarf cray or two be alright with 6 tiger barbs(Possibly ten soon) in a 29 gallon?
In a large enough group, tiger barbs are known to be less nippy. I think if you have at least 10 barbs it should be fine, though there is obviously never a complete guarantee. Good luck!
Could I keep a CPO with a honey gourami and a few guppies in a well planted 10 gallon?
A CPO would be fine in a 10 gallon but guppies and honey gourami are not a great combination nor are they really suitable for a 10 gallon! Both require at least a ~15 gallon long tank, sorry! Something like a harem of least killifish would work well, though. They’re tiny and very interesting to keep. 🙂
Thanks for the info! I love this site.
I have a 20 gal planted tank and am gonna make it a community. I already have 7 neons, 3 cory cats, 2 siamese algae eaters and 1 ottocinclus. I would like to add one dwarf crayfish, can i do that? or are they a species that likes to be in pairs?
Hi! You could add one dwarf crayfish but your current stock is unfortunately a bit messy and already at its max and I would personally fix that up before introducing even more fish.
Siamese algae eaters grow very large and need a lot more room than your 20 gallon, so it would be a good idea to rehome them as soon as possible. Both Corydoras and Otocinclus are group fish that should be kept with at least five, so after rehoming your algae eaters you can expand both those groups. The neons would appreciate two or so extra friends as well.
Good luck! 🙂
I kept two dwarfs (a male and a female) in with forty odd cherry shrimp, and the shrimp ate the crays after they molted, so if you keep them with cherries, be aware that this can happen
Wow! I’ve never heard of that happening and many people keep them together. Are you sure the crays weren’t already dead? Cherry shrimp are not known for eating any live animals.
how does one discern between a live moulting cray and a dead one?
also, how big of a tank should i use for breeding them?
It’s pretty difficult to tell as they’ll be hiding when moulting and you can’t disturb them, so I guess there’s no way of really knowing. I do know cherry shrimp are definitely 100% non-aggressive, which is why it strikes me as odd! A silly question maybe, but was the tank in question cycled? Did you test the water values?
For casual breeding of dwarf crays, a 10 gal would be a good place to start. Gastromyzontidae on Tumblr breeds dwarf crayfish and should be able to tell you more about it.
it was running for over a month with fifty shrimp before I added the crays, but I’m not sure if its cycled, because I cannot find anyone who sells test kits locally, and shipping one from stateside is prohibitivly expensive
I am “godarethereanyusernamesleft” on tumblr, message me
Hi I am starting a shrimp tank and have pigmy cories about half an inch I was wondering if I could have the dwarf cray with them and if it would kill them and too many baby shrimp because my colony is not very big yet thanks!
My dwarf crays never touched any shrimp, so I think that would be possible if the tank is large enough (10-15 gallons).
Your information has been very helpful. Do you think it would be ok to get two Mexican Dwarf Crayfish?
My apologies for the late reply! If you have at least an 8 gallon setup that would be fine.
Is it normal for my Mexican Dwarf Crayfish to hide a lot? Thank you for the information. Do you think it’s ready to molt?
If it hasn’t molted in a while that may be it! Keep a very close eye on it though just to be sure, and closely watch your water values.
I have a dorf she was on her back today when I got home I picked her up took her out and she’s in a separate place, I’m worried because she can’t move at all!, Nothing she looks dead other then the color, is still vibrant but the small back legs underneath the tail the white clearish color ones will still slightly move but no claws no reg legs she’s 7months, only molted once.. And I’m thinking is she stuck in her next molt? There was a goldfish in the tank it’s twice the size of the crayfish Iv taken it out as well.
I’m afraid I can’t really help you with your dwarf cray as there isn’t that much you can do. You may want to have a look at the comment underneath this one, as the commenter had a similar problem and did pretty much all there was to do!
Also, goldfish and crayfish should not be kept together. They have similar temperature requirements but are otherwise incompatible. You may want to read the common goldfish caresheet here or the fancy goldfish caresheet here depending on what type of goldfish you have!
Thanks for your great article and answering all these posts.
Four days ago, I found one of my dwarf crays — Cambarellus shufeldtii — had suffered from a bad molt. However, the molt was limited to affecting what appears to be only her two front legs/claws. Prior to the molt, she was missing a front claw. When I discovered her, she had a whitish, new limp claw where the missing one had been, and her original claw appeared to be help back against her undercarriage. Immediately removing her to a small plastic 16 oz. container, she is now alone with no threat from other creatures, has her water replaced constantly and kept extremely clean/good basic levels upon a 5-part strip test. There is an airstone cranking out tons of bubbles. It also holds down at her level a couple snippets of plants, including some hornwort. She appears to be able to breathe and eat, however, due to her disability, she resides largely on her back, sometimes on her side, and is not really mobile.
A food I sometimes feed them, wardley shrimp pellets, break up fast in the water and become a soft fluffy lump, so…. I have been able to gently push one of those next to her mouth, and she eats. It is a humbling, endearing act, and watching her eat through a magnifying glass, brings out the best in me.
I am wondering about advice you have for trying to encourage removal of the last bits of tissue preventing her from properly extending her claws. So far, I’ve done almost nothing other than what I described, and briefly tried a slow, constant water change, basting out the water to just above her, and then adding clean water, creating slightly enhanced current that gently pushed against her, appearing to loosen some of the remaining molt tissue. Not wanting to injure her, I am extraordinarily cautious with her and try to be as gentle as possible in all activities with her. Four days of this, and she is eating, breathing, still occasionally trying to rip off the last of the molt tissue, using little jumping/sudden movements, though futile so far. I can add some broken up cleaned egg shells, if you recommend. Also, I have heard of putting her in a bowl of room temperature dr. pepper soda for about 15 seconds, followed by putting her in whole milk, before returning her to her container with the water/bubbler.
Any comments you have on the water therapy I’ve tried, or on the egg shells or the odd sounding submersion technique would be appreciated. I love her very much; her name is Brownie, and she is a trooper. Four days of this and she is still clearly fighting to stay alive, so I am right there for her, though I am so scared to try the dr. pepper/milk thing, however the source of that advice is the man who sold them to me, who really knows a lot about crayfish, raising many types and really trying to be caring with his advice to me.
So sorry for the long note. I adore her and want to treat her right, with God watching. Thank you so much for any advice you can offer.
So sorry to hear about your cray, I really hope she does recover although you should unfortunately keep in mind that this likely won’t happen. The dr. Pepper/milk technique sounds a bit far fetched to me and I wouldn’t try it personally; she is already very weak and stressed and something like this may send her over the edge.
I have never dealt with a cray stuck in molt, but I don’t think there is much more you can do. A hiding place like a shrimp flat or tube might help keep stress levels down. Be sure to feed her and the other crays an invert food with plenty of calcium. Hopefully she’ll eventually just manage to get out of the molt herself.
I’m really sorry I can’t be of more help; you’re already doing basically everything possible. Good luck, and please let me know if she pulls through.
Thanks so much for your thoughtful advice and reply. I as well am hesitant to try that intense procedure I mentioned. Last night I did add more plants to her container, as well as some cleaned egg shells with no membrane, etc. She is able to get snuggled into spaces with plants all around her, and was busy using her undercarriage claws to mess around with the plants and appeared to be nibbling as well last night and this morning. I was very optimistic. The plants provide her a great deal of coverage so she can feel more secure. She also has a small cardboard box with a part of it’s side missing which I slip over the container during the day, which gives her lots of darkness without interfering with her airstone or air getting into the container.
I also feed her Hikari Crab Cuisine and their bottom feeder tablets, though it was the wardley shrimp pellets that break up the best as soon as you put them in the water, becoming a mushy ball that I watched her eat from several times since this began. They make a mess in the community tank, but have proven super useful in this case.
At night the box comes off, and I can tend to her container in dim light, and that’s when she gets a 5-step water test every day, so she is in pristine water, with plants and daily food.
If she gains use of her front limbs, I will move her to a larger container and she can have a shell/cave, but never back to the community tank. Right now she is still trying to shake loose the remaining tissue holding those claws back, and I think she wouldn’t go in a cave as she’s on her back or side, and needs a little space to do the shaking/jumping thing to try and shake off the remaining little bit of tissue. In the community tank they all live in big sea shells, but to shake off this molt, she needs a bit of space. She is an adult, so if she never molts again and remains disabled, I am glad to take care of her. My Mom was disabled and so I am more than ready to feed her, keep her safe and accommodate her needs. Thanks so much for your concern. I really appreciate it, and your knowledge. God bless.
Just an update that two weeks to the day Brownie was discovered with her partial molt, she is alive and doing well. She lives in a 1/2 gallon tank with several plant clippings, a moss ball, cleaned egg shells, some nice brown leaves and a gravel substrate, with a few shells and caves for her to get privacy. The tank has a bubbler and is kept in a dark spot so she has minimal stress. She gets her water cleaned twice a day and fresh food added at that time (as her water is basted out, removing any uneaten food or debris). She seems alert, enjoys hopping around to the plants and then clinging on them nibbling algae and plant material. She loves eating the leaves. Just thought you’d like to know…
What should I feed a Mexican Dwarf Crayfish?
There is some info on feeding dwarf crayfish in the article. An invert food like Hikari Crab Cuisine supplemented with frozen foods, pieces of algae pellets and blanched veggies like peas makes a great diet. Good luck!
I’ve heard Crawfish are escape artists, how do you prevent them from escaping through the opening for the filter and air pump?
Dwarf crayfish have less escaping problems than their bigger cousins, but you can prevent problems by lowering the water level a bit to make the openings less easy for them to reach if necessary!
I’ve been reading about the Mexican dwarf crayfish, but I cannot find any info about how many are needed to keep them happy. Is one happy or do they need to be in groups?
That’s an interesting question, I’m actually not really sure! I usually recommend getting at least a pair, though, because it’s just more fun to keep at least two. I don’t think it’s necessary, as crays are not really prey animals, but I’m not sure.
Hi could I keep a piar of cpos ina 8g tank? It would be planted and filterd with aa hob filter, I wouldhave a lot of hiding places too.
Hi, yes that would be a great setup if the CPO’s are the only inhabitants! If there are other fish/inverts as well, it depends on how you stocked it 🙂
Hi this article was very helpful I had a few questions though first I wanted to know what the tubes you used are under the behavior section and where I can get em also in a 80 gallon tank mostly populated by tetras
The tubes are shrimp flats, dwarf crays love them! You can get them on Amazon or at some aquarium stores. If your 80 gallon is mostly populated by tetras and not currently overstocked, you could keep a few CPO’s or other dwarf crays no problem. I’d say go for one pair first and maybe get another pair if it turns out you enjoy keeping them!
I read your article and i found it very interesting. Thanks for sharing this with us.
Still.. i need to be sure of something. I have in my tank some red sakura and a couple of bamboo shrimps. I am eager to get a few mexican orange crayfish and i am afraid they will kill all that moves in the tank.
What do u think? 🙂
Sorry about the late reply!
I totally trust cpo’s with sakura shrimp, however I’d be careful with bamboo shrimp as their fans are very vulnerable. That being said, cpo’s are not that aggressive compared to other crayfish, so you could give it a try. You could also ask around on forums to see if anyone else has combined them and whether it was a success, I haven’t personally tried it!
Good luck! Sakura shrimp, bamboo shrimp and dwarf crayfish are all super fun to keep, so I hope it works out.
I enjoy reading your blog on the cray. I would love to start a tank on my own, but I am finding it difficult to locate the CPO cray in South Africa. Do you have any advice on where I can start looking as I am sure I will not ba able to import the live stock.
You could try looking for aquarium stores that sell online if shipping live animals is allowed in your country! That way you could order them online and have them shipped to your house 🙂
I have been having good luck with Aquabid.com, you can check and see if any sellers ship to your location.
Completely forgot about Aquabid! Definitely worth a try.
Are dwarf crayfish illegal in Australia?
I don’t know! I live in The Netherlands. A lot of animals are illegal to import there though I think.
I know your from the Netherlands, I’ve searched every where online and can’t find the answer, I’ve never seen one in real life. Alot of fish/inverts are illegal in most states of Australia, but the state I live in has less illegal fish/inverts.
On an Australian fish keeping online forum someone said that they saw some in their local fish store, but they weren’t on sale.
There is an Australian native cray that is the same size as mexican dwarf crays, but are just as destructive as most other crays.
Dwarf crayfish are very uncommon in my country I guess. I’ll probably never find one.
They are not illegal, but importing things to australia is very expensive so invertebrate selection is minimal.
Thanks for sharing 🙂 at least you guys have Australian red claw crayfish (Cherax quadricarinatus)… although those can’t exactly be classified as ‘dwarf crays’.
I have a 10 gallon aquarium with a 4 Tetras and 6 small ghost shrimp. Would I be able to add a couple of the Orange Dwarf Crayfish to the tank if I had enough hiding spots or will they attack the Ghost shrimp?
I think you can safely add a pair of CPO’s to your tank if there are a few hiding spots. They are usually not very aggressive. 🙂
Is there any reason to add a pair? I was trying to buy 2 but the place I chose only had one in stock so I just went ahead and bought it. Seems like he is doing OK so far and has already found the crab pellets I dropped in for him.
One is fine as well! In a 10 gallon a pair would’ve been possible too, which is why I mentioned it, but the lighter your tank is stocked the better. Good luck with your new cray! 🙂
Hi! Thank you for the insight on the dwarf crayfish. I’ve owned two crayfish in the past but sadly they got way too big for the tank (and a little too hostile) and I had to give them back to my local fish shop.
however, I just recently put in a special request order for a dwarf blue crayfish – it should be arriving Thursday. How do I know I’m not just being sold a baby Cray that will get colossal like the last two? Also, one last question – the first Cray I got was electric blue, but the second one once she molted went from blue to brown. Any way I can distinguish the true blue ones from temporary mutated colors while still at the fish shop? I don’t want to spend $20 on a regular Cray. Thanks in advance!
Sorry to hear you’ve had some bad experiences with crayfish in the past – I think dwarf crayfish are a great choice, as they do stay small and peaceful. 😀
I’m unfortunately not entirely sure how to tell dwarf crayfish apart from baby crays because I don’t have personal experience with the larger species. You may want to ask around on invert forums for more info on that!
As for color, blue crayfish unfortunately don’t always have stable coloration. I suspect it may be because blue is not a naturally occuring color in dwarf crays. There’s some speculation out there on what affects their colors, but you don’t really have any guarantee. I do know that CPO (orange dwarf crays) are a pretty stable color type, so if you want to be sure your cray doesn’t turn brown I think those are your best bet. You can also try feeding color enhancing food, but I’m not sure how effective that is.
Hope that helps a bit, sorry I can’t give you more info!
My mom bought a blue lobster, that is what she was told at the pet store, I believe it is a dwarf blue crayfish. It is in a 55 gallon tank with about 10 to 14 koi and goldfish. It has been missing for a week! Search the entire tank as well as the entire room. It has not melted since they have had it, 2 – 3 months. Is it possible that it dug into the rocks in the bottom of the tank? None of the rocks look disturbed.
That is a possibility, but considering the overstocking of the tank I think it’s unfortunately more likely that the crayfish passed away of ammonia poisoning and was eaten by the fish before you found it. Common goldfish and especially koi are not suitable for life in any type of aquarium (not even temporarily) and you should move them to a proper pond as soon as possible. With your current stocking level extreme stunting and eventually death will unfortunately happen soon. In most parts of the world it’s the perfect weather for moving fish to a pond, and I really urge you to do so. Common goldfish grow to up to 12 inch and koi get much, much bigger than that, 45+ inch is not uncommon at all.
is it normal for my crayfish to bend its body?
I know I’ve seen my crays bend their bodies a few times, like they were trying to reach their tail. This is especially common in pregnant females I think, I see my shrimp do it all the time as well when they’re cleaning their eggs. If your crayfish is doing this all the time or if it’s stuck in this position, though, there might be something else going on like a problem with molting. In any case, I’d recommend you check your water values with a drop test kit if you’re worried at all. Bad water values can make them do strange stuff as well! Keep an eye out for heightened ammonia, nitrite and maybe unusual temperature differences.
Hi! I recently purchased an orange dwarf cray and although he was active and walking around the tank, lately, he has been hiding in his rock cave. We never see him! I did a water change and he seemed healthy and feisty but he eventually wandered back into his rock cave. He currently lives with my male Betta and I was told at the pet store that my cray would make for a good roommate. I was just wondering if his hiding behavior was normal or if I should be concerned. He is given pellets but it’s not like he runs out from the cave every time they fall to bottom. Thanks and I enjoy your site, it has been very helpful!
First off, a crayfish and a betta are unfortunately not a good combination at all. Their temperature requirements are quite different, and the crayfish can damage the betta when it’s asleep on the bottom of the tank. I’d always check on fish forums and such instead of asking at a pet store, they unfortunately tend to give you false info in order to sell more. 🙁 I’d get a separate ~5 gal aquarium for either the betta or the cray.
As for the hiding, the most logical reason I can come up with is that your cray needs to molt. When they molt they get very vulnerable, which makes them instinctively want to hide. It should come out once the molt is completed; as long as you’ve been feeding a nutrient-rich food with enough calcium he should be fine! Good luck 😀
Hi, my name is Will and Im owning two blue electric dwarf crayfish. I just got a big surprise seeing many black eggs under the tail of one of them. Any of you can tell me what to do with this ? Is there any precaution to take if I desire to let’ em grow up ?
Congrats on the pregnant cray 😀 I haven’t actually bred crays myself, but the best tactic seems to be to leave the female alone and make sure she isn’t stressed out. Feeding extra nutritious foods may also be a good idea. Provide the babies with some extra shelter so there won’t be too much cannibalism!
I think that’s all you can do, really! If the babies don’t make it this time, don’t be discouraged, as the female will likely start bearing eggs again soon. 🙂
Great post! What other species of crayfish do you have?
Glad you liked it!
I don’t personally own any other species of crayfish 🙁 I’d love to have an Electric Blue or Snow White one day though, but they need a pretty big tank to themselves so that’s something for the future.
How about you? 😀
I’ve got an “electric blue” Procambarus alleni, two darker blue Procambarus clarkii, three white Procambarus clarkii, three orange Procambarus clarkii, a bunch of Cambarellus shufeldtii, as well as some brown/red Orconectes palmeri creolanus and another specimen that I have yet to identify!
Ugh, jealous 🙁 that sounds great! Do you have any tips for me for if I ever do set up a tank for one of the bigger crayfish species?
Sure. There’s a lot of tips at the little website I moderate: http://www.reddit.com/r/Crayfish/comments/17y41s/the_essential_guide_to_keeping_crayfish_as_pets/
Will definitely be checking that out! It’s so cool crays are so easy to obtain where you live. I have to drive mad distances to find them, haha :p
Could I fit a trio of dwarf crayfish in a 6.5 gallon tank? Could I fit any other fish in with them?
Yeah that would work, though I’d go for the smallest species like shufeldtii. Other fish I would not recommend, but dwarf shrimp make a good option and will be left alone! 🙂