Picture of Fiddler Crab Care
Since there are about 12 million fiddler crabs dieing every day because of uneducated owners,
i decided to make this instructable
Most of the problem is about how pet store employees are miseducating buyers and telling them the exact opposite of supplies...

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Step 1: Supplies

Picture of Supplies
Here are the basic needs for a fiddler crab
-A 5 gallon tank (the bigger the better)
-a heater (Yes fiddlers get cold)
-A filter (Go for the internal ones for fiddlers because fiddlers are great climbers and can crawl up the intake tube and escape)Never go for undergravel filters for crabs...
-Sand (Fiddler crab legs are designed to crawl on sand,don't go for gravel because it makes it hard for them to crawl on and believe it or not fiddler crabs will die of frustration)
-Sea Salt (Fiddler crabs live in brackish water-half salt half fresh-and will die in months if in freshwater)

Note:Fiddler crabs are NOT semi-aquatic,remember they live in beaches not the ocean

Step 2: Determining the gender

Picture of Determining the gender
female fiddler.jpg
The gender of a fiddler crab is easy to determine,male fiddler crabs have on normal claw and one big claw,while females only have two normal claws

see picture below

Step 3: Choosing a crab

Picture of Choosing a crab
Choose healthy, active fiddler crabs with all their limbs still intact. A good set-up is one male to about three females. Crabs are sold in many pet stores. People also like to catch fiddler crabs on beaches.

Step 4: Feeding

Picture of Feeding
Feed your fiddlers algae disks or commercial crab food. They also find shrimp pellets and frozen bloodworms quite tasty. A slice of zucchini is an occasional treat. Remove uneaten food after 24 hours, or you'll be growing mold and smells.

Step 5: Heating

Picture of Heating
Keep crabs comfortable in a room-temperature (75-85 degrees F) environment. If the water is too cold, invest in an aquarium heater or basking bulb.
I just bought mine at Walmart yesterday out of impulse. I saw that they were in a tank of water and thought that's how I take care of them not knowing the proper way. This was very helpful thank you

just wanted to say Thank you. I picked up a few fiddlers for my classroom. Your information has been very helpful

ahudgins3 years ago
Just for future reference- dying** not dieing. Spell check is your friend when you're attempting to be an athority on a subject.
Just for future reference- authority** not athority. Looks like you should make friends with spell check too, especially when correcting someone else's spelling. ;)

+1 my fried

Your comment is totally priceless. Isn't it ironic?
I recommend using the spell checker yourself! :)
Depending on where you come from, it can be dieing and spell check does not find that spelling to be erroneous. Dying means to dye something a colour or to leave life. Dieing on the other hand, can mean to leave life or to cut with a die cutter depending on what you prefer. English is a great language of confusion and we are all better off if we do not correct others on the finer points until we ourselves know all the finer points.
RyleeM1 month ago

I have just bought 2 fiddler crabs from Walmart (Both female) and I had asked one of the workers what you need. I bought rocks and a 1.5 gallon aquarium kit. I had no clue you need a heater and stuff. She only told me to get betta pellets for food and some rocks. She completely did not know what she was talking about and I am very frustrated. Would you think they could survive in 1.5 gallon aquarium kit?

Subotai RyleeM26 days ago

they were working at Walmart, what did you expect? They get paid minimum wage in a soul destroying job that robs them of their dignity.

pvcpipefan1 month ago

i just bought two fiddler crabs from walmart and now they are sick, won't move and one lost one leg. i think its because i used gravel. thanks for this instructable really helped. will now make a lot of changes!

foodislove3 months ago
I bought a couple at walmart, and i think these crabs are sooo adorable. Walmart doesn't even know how to take care of them. I make a little beach with some brackish water for them. They are great climbers, and they can grip on anything including glues that are used to make the fish tank and will climb out if there is an opened gap. I feed my crabs with betta pellets, plankton, and shrimp pellets.

I've had some crabs for a few months in a 5gal aquarium with goldfish and snails. The water is low saline content, and I give the crabs "salad shrimp" occasionally, as well as white "tums" for calcium. They love the tablets and the male crab will sometimes sit on one to hoard it till he's done eating. The snail likes it, too.
The crabs have a plastic castle to climb on to get out of the water. I'm looking at your page to think of a new tank (bigger box) so the crabs get more sand area. Thanks.

NissaP3 months ago

Hello, need a little help. I am one of those people that did not get good info from the pet store. We got a red crab yesterday and he has already lost 2 legs in a fight with a catfish. I put him in a temporary home and he seems to be doing ok. Should I put time and $$ into a suitable home or will he not survive? Thank you

As an employee at Walmart, don't blame all of us for poor care.
My Walmart actual takes good care of the fish, got my Gustavo and my baby fiddlers yesterday, all healthy and high active. I have just two fiddlers so I got a single gallon tank until they get larger. I was going to get fine gravel today, but I may get sand instead, but the man told me that I should get an ornament for them to climb on and so they can bask and not to keep them underwater all the time. He actually takes the fiddlers out 2-3 times a day. He like to bring food for them too, maybe some freeze dried bloodworms like my betta loves. but im excited for my babies

pjclaybaker.3 months ago

my son received a fiddler crab and a red clawed crab for Christmas. We have them in a 5 gal tank, set up as you have recommended. We do not have a heater but do have a basking lamp on most of the day. The crabs do not seem to be eating anything. We put crab pellets in a plastic upside down lid, tried a few little pieces of cucumber and part of an algae tablet. All of it just sits there until we take it out. It's now been 4 days. They seem inactive and spend most of the time hiding. What do you recommend?

I think my fiddler crab is dead hes been like that for a day plz help
lilsoph4 months ago

If our crab could talk he would most definitely thank you! We bought it from walmart and set it up as they had him in store.

A week later it was upside down. we presumed dead. Laid there all day until my hubby got him out to get rid of him and noticed he seemed to be moving slightly. We researched (as we should have done right away) and came across your instructions, which we followed. 3 months later he is healthy and active and we are about to get him a couple of friends. So thanks :)

plamay1 year ago
Thanks for this info. I have been looking and looking and came across your post. We live in Pensacola FL caught some fiddlers actually about a dozen so I actually should return some to the shore. They just seemed so funny and thought the more the merrier LOL. Anyway i pray I can keep the little fellas alive. I brought home some of the water from the shore I was wondering if I can just keep changing out the water from the same shore instead of commercial salts ?
rjoos1 year ago
This isn't a bad way to do it but if you want fish in the same tank they wouldn't have much room.

I really recommend Underwater Islands they have these really cool products that make it so you can have crabs in your tank but not have to have your tank only half filled.

I attached a picture from their website so everyone can check them out if you want.

their website is

Check it out and let me know what you think!
rjoos rjoos1 year ago
Wups that didn't work, I thought I had attached a picture.... let me try again.
reine4321 year ago
In your instructions you mention "there's a basket under here to hold up the sand, and the heaters under there".
please advise what type of basket you use.
Also another question, when fiddlers molt, ("they will stay upside down for hours") are they ever upside down underwater for hours? I assumed mine was dead- maybe he was molting? thanks so much for all the info!
dblake51 year ago
You are a Jack!@# for trying to correct someone's spelling in an info page...Get a Life!!! This for help with Fiddler Crabs and show how to make them happy not a grammar check convention!!! I am here because I bought crabs from Pet Supermarket. and they are dying also!
Climber032 years ago
You can have a way smaller tank about about a quarter gallon
Biggsy2 years ago
I found this Ible VERY useful when i began thinking about owning some red clawed crab... I have a Facebook page thats sort of part blog on my journey into owning crab, if you have crab, or are looking to get some, feel free to join my page
Mauigerbil2 years ago
Lol my friend got a fiddler crab for her birthday from a friend and she had NO IDEA how to take care of one. She put it in a full fishbowl with sand, and then with further online research, she found out it was slowly dying in there, so she drained it to just a little water and a rock. She hates that thing like the plague and is her least favorite present. Poor girl..

At least her friend didn't get her more than one or else stating it would be awkward..
Also why is it tagged under tacos?
I'm very glad this little bit on crabs was posted. I just rescued my fiddler crab from the wrath of Walmart. Apparently they don't feed the crabs because they do not sell what these crabs need to eat and they also keep the poor creatures confined in small plastic dishes with pebbles and a small amount of water in the bottom. Tomorrow i'm going to get the tank and all the recommended accessories and chlorine removers/aquarium salt. Once this little fella (i named him Bob) gets settled, i'll go back and save the others. That's a real nice example tank in the picture here and i hope to set mine up similar to it. For future reference to anyone who has ever considered purchasing an aquatic animal at Walmart, it probably hasn't eaten, slept, or had adequate housing for quite some time so don't be broken hearted if the poor dear dies the day after you bring it home. I saved a dwarf aquatic frog from there once (it was in the same kind of small plastic dish as the crab), gave it a nice large bowl and some food but he/she died the next day. Most of these stores do not feed these animals because they don't know what they eat and apparently they don't know how to keep them housed either. So yeah, just thought i'd throw that out there.
I've also seen tons of dead fish at the Walmart. Absolutely pathetic inhumane care they give to their animals. I'm not sure purchasing the poor creatures is the best route, Walmart will simply respond by restocking them with more helpless creatures and being satisfied that their "products" are being sold. Maybe filing complaints with your local humane society or other authority would be more productive in getting Walmart to change its practices.
Indeed, walmart is terrible and i know that they will restock if i purchase the animals however those animals deserve some kind of a life away from the store shelf and it's against my very being to leave them there to die. Sadly, our local humane society is worthless. They do not do rescues or work for the "lesser" creatures such as fish and invertebrates. It's difficult to even get a horse/dog/cat abuser prosecuted here. I live in a very "conservative" town where animals take a back seat to guns, "god" and human enjoyment. The dogs and cats from our pounds are still sent to animal research facilities because the city council voted to let it continue even though many, including i, protested the decision. Every spring and autumn there is a deer cull (they hire snipers to come in and take out roughly 80 deer, which include fawns, adult males and adult females) in our two wooded/marshland parks because people complained of deer in their gardens. Illegal hunting is overlooked as well. This is the expected extreme behaviour of my town, which is sadly considered the "birthplace of the republican party" and one of Ted Nugent's home towns. Jackson, MI is not a nice place to live for animals or those that care about animals. If i could get national attention for the atrocities of this town i would gladly do so. But the problem is, who will listen and who will not be bribed or bought off?

In the end though, i'm glad i saved the fiddler crabs from the walmart. They do restock them after the others die on the shelves. A couple weeks ago i noticed they were carrying purple clawed fiddlers. Such beautiful little creatures. Perhaps i could, maybe, just maybe get through to the pet department manager to post how to properly care for the fiddlers so that at least when people buy them, they know how to care for them.
how much sea salt do I add to a 1 gallon tank and one fiddler crab
What ratio should the brackish water be?
halo99 (author)  RedneckAsian4 years ago
Depending on how big your tank is brackish water is just a fancy word for salt water so for a 5 gal i would put in half a teaspoon heres a website for you,%20Fiddler%20Crabs.htm
(I couldn't start a new comment so I decided to just reply.) I was wondering about your internal filter. I don't currently have a filter for my fiddlers, can you share the name or brand of yours? Also, is it a cordless filter? i'm curious. And where did you find those tunnels? I would prefer to get something more natural looking to camoflauge with my tank, but at this point I haven't found anything yet. Thanks in advance
he has a whisper internal filter and looks like pvc joints
halo99 (author)  desreydel4 years ago
Sorry I didn't reply sooner,I didn't see any new comments on my inbox. Should I still answer your questions because I don't want to tell you something you already know.
Arbitror halo994 years ago
Brackish water is only partially salty.
im gladi knew a bit abou keeping fiddler crabs when i got mine, i never thought they would be able to reach the heater or filter intake, (tank is a 35-40 tall) after i found that out, i imediatly blocked off the slots in the hod of my tank, still somehow the female got out fter a very and made it into my sisters room and into her underwear (make all the jokes you want, i sure as hell did) and the male vanished before that though there were shell fragments, the only one large enough to reconize looked like the females claw, which ended up being a piece of the males shell who im guessing was canabilized while molting, unless my algea eater likes crab, they also ate 2 of my danios, though one kept swimming into the holes in my lava rock and getting stuck, and the other one looked like it got conered....
halo99 (author)  minipancho944 years ago
Lava rock is notorious for caving in and or squishing fiddler crabs,thats why most experts suggest sand since fiddlers do live on beaches,as for molting i suggest isolating her until she has fully molted as because she is in her weakest form... And for the canalization,do you feed your crabs often? I would suggest putting feeder fish(10 cents)just incase they need a snack...