Rainbow Land Crabs (Cardisoma armatum)

[pufferpuggirl]

Does anyone out there have any experience with Rainbow Land crabs (Cardisoma armatum)? I've had 3 for a couple of months now, and they are doing very well, but as with anything I keep, I want to make sure I'm doing my best for them. I have been trying all morning to find more information on them -- about what they eat specifically. I've been to a million sites and the most information I can find is, "they eat anything offered to them, vegetables, fruits and meats" -- but nothing to tell me which vegetables do they eat, which fruits do they seem to like and what sort of meat, and how often?

I've been feeding mine crabs rings (a food made specially for different species of crabs), fish pellets, bloodworm, some shrimp pieces and occasionally pieces of grapes (because I read somewhere that they like those). I'd just like to be able to offer my trio a better variety of foods to ensure a long and healthy life for them. I must be doing something right though because one of them has already molted, which is good. I recently moved them from a very small 2-foot tank to a much nicer 3-foot tank, and they seem happier with the extra space, however, I think I will need to modify their tank fairly soon. When I originally got them, the LFS that had them had housed them in a tank that was mostly water with some rocks and bogwood sticking out of the water for them to climb up on. So I mimicked that when I got them home to my aquarium. Since then, I've found out that, just as the name implies, they are "land" crabs, not truly aquatic crabs. I know of several shops that have kept them totally submerged with no way of getting out of the water, and I think that's horrible, as they aren't meant to remain underwater 24/7. At least I've always offered my crabs the ability to come out of the water if they want. Thing is, unless they have a "swimming leg", like a fin, then they aren't truly aquatic, meaning they aren't supposed to be under water all of their life. I think most smaller crabs are sold as aquatic crabs, but if you look at their natural environment, most of them live at the water's edge, but not totally in the water 24/7.

Anyway, didn't mean to start a lecture here. I would love to hear from anyone that has either had a RLC in the past, or currently owns one and can give me an idea for a variety of foods to feed. I'm mostly interested in the veggies and fruits that are fed successfully. I just want to be able to provide the best I can for my crabbies as I'm very fond of them. They are most interesting and a lot smarter than most people give them credit for.

I want to say thanks in advance for any and all information you can give.

[ste123]

hi,
i have had a very similar experiece to you, only mine seems to be ending i a bad way.

i bought 2 rainbow crabs a few months ago and had the same set up as you did, as i too was copying the place i bought them from.
a few things happened, such as i moved house so transporting the crabs was difficult. then choosing where to put them was a difficult decision. I put them in the living room but this seemed to be a bad decision as my housemates can be quite loud and the crabs started to hide all the time. so put them back in my room and they started getting bak to their usual selves.
then i bought a much bigger tank, and its a land set up with a lunch box full of water for them.
unfortunately one of the crabs died the other day. He was quite large and didnt really have much colour, so im assuming he was a fully developed adult. But i just found him on his back dead.
since this, the other crab has just speant nearly all his time either hiding, or in the water. he hasnt eaten since.and has become very scared of me.

i was wondering, before your crab molted, did he show any behaviour that could have suggested he was going to molt?i thought maybe not eating, and staying mainly in water could possibley be a sign that he is going to molt?he hasnt molted since i got him, and its been about 5 months now.

also how long does it take them to molt, and did you see it, or was it finished when you noticed?

im going to buy 2 more crabs, as the tank is big and needs more crabs lol

[pufferpuggirl]

Well since I posted that thread, I've modified my tank to give more "land" spaces, but the tank is mostly water still.
Actually I didn't notice any real behaviour difference in the crab that molted, although I have read that they will stop eating before a molting. I guess because I've got the 3 of them, I didn't concentrate on any one of them, and may have missed some of the signs of the pre-molt. I didn't see the crab in the molting process, but I did see him just as he had come out of his old shell and was still soft. I worried all night that he would be eaten by the bigger crab, but that never happened, thankfully.
Neither of my other 2 have molted, but I don't know how long it's been since they did it last, could have been just before I got them. I did read that the older they get, the less colourful they are, so the one that died on you could have died from old age. Surprisingly they live from 5-7 years, which is much longer than I had thought. I am sure now though that I have 2 females and 1 big male, so that's good seeing as I've read that the males can fight to the death, so if I were you, I'd make sure you have only 1 male and the others females.
Good luck with getting more crabs to add to your tank, stay in touch and let me know how it goes for you.
I'd love to see my big guy molt, but I will probably miss it and find the shell after the fact, which seems to happen all the time with my other aquatic crabs. But in answer to your question, I believe they can molt over night, so probably only a few hours to actually do the deed, but much longer for them to harden up afterwards. My crab that molted is just starting to get her colours back, and it's been several weeks since she molted.

[ste123]

Hi, thanks for the reply.
I was thinking of getting females, but ive heard they're not very colourful and i would prefer to have crabs that are colourful, as shallow as it sounds haha.

yeh i will let you know about my current crab, i cant stop checking on him but he's not happy, im sure of it.

[pufferpuggirl]

The females may not be as brightly coloured, but they are still colourful .... but what you need to remember is that, as the RLC's age, they get more aggressive and territorial, and if you have 2 males together, you may end up having one kill the other, or both dying as a result of a confrontation. That's why you're better off having the females.
And maybe your guy is missing his company, could the one that died have been a female? I believe that most living things (and that's most, not all) prefer to have company rather than to be on their own, so he's probably wanting some company in the tank with him.

[ste123]

the one that died wasnt a female.the flap underneath was too narrow for a females. and they did used to fight occasionally, but nothing ever came of it. mike, the one thats still alive, wud usually just back away.the place where i got them dont have any more, so i'm going to have to buy online. have you got any pics you could upload on here? so i can see the females. il upload pics of mine just so you can see them.

[ste123]

this is mike, the alive one.


this is gary lookin mean lol


this is the old set up and tank


mike

[Eager Newbie]

I like crabs, they are.....eccentric.
Nice colors on Mike in the first picture.

[ste123]

Oh btw, do you have a heater for your tank?
Mikes been staying by the water and i think its because of the heater i have for the water. The rest of the tank seems quite cold now and i think it needs to be heated.
ive looked into it but i dont know what to get for heating

[pufferpuggirl]

I've just taken a photo of my new set-up, but I'm also going to upload my old set-up too. I have photos of the last female I bought (at first I just got 2 and then decided I wanted another female). Yes, I do have a heater for my tank, and the air seems to stay fairly humid, which is what they need. Is the top on your tank nice and tight? And what do you have your heater set at? In the photo, your heater is above the water line, not a very safe thing to do -- all the glass needs to be under the water. They will sometimes crack when they are exposed.

Here's the new tank, the 3-foot set-up


Here's the old set-up


Here's one of the females (but not the one that molted recently)


Here's my big male



I don't have any photos of the crab that molted recently, but I will try to get some of her, she still hasn't gotten her colour back yet and they look very different before they get their colours back.

[ste123]

the heater has dots on it that have to be under water, and the rest of it doesnt need to be. its all under water now though.

the female looks nice, i'll be getting one next week.

the lid used to be tight, but its not anymore as the lid for the new tank costs as much if not more than the tank. in fact, what tank have you got? looks similar to mine. is it "tetra"?

ive got the top of the tank covered but not with the proper lid.

how do you clean out ur tank?coz i can just take the lunch box out and change the water, but when i had the same set up as you i found it hard to clean and it would smell more too

[pufferpuggirl]

I'm not certain what brand of tank this is, I threw out the box, but it wasn't a Tetra. And yes, I do have to clean this tank every 4-5 days to keep it clean, but I don't mind, as I've got a Red-Claw crab in another tank and I usually do them both at the same time, doesn't take me very long.

See, that's what I worry about if I go to more land in my tank -- losing humidity - because right now, my tank is nice and warm in the water and out of the water. I don't see how I could keep it as humid if I was to go to a mostly-land type tank. I'm thinking of doing something similar to how I used to have my mudskippers tank -- which is to build a retaining wall, and have a deep end of water with a submerged heater, and then to have a "land" side, and hopefully the high temps from the water will keep the air warm as well.

[pufferpuggirl]

What part of the country are you in ste123 ? I'm just curious because you said you can't find any crabs locally to you. Where are you going to order them from?

[ste123]

yeh im gona build a wall, soon as i can figure out how lol.

well im in derby at the moment. im a student. so the crabs lives here with me. but in the summer i take them home to cheshire. i got them from pets at home in stoke, but they've not got any anymore, ands i went to pets at home in derby and they didnt have any.

[pufferpuggirl]

Well, I've got an idea on the wall..... if you're interested.

And you might go to Maidenhead at Trowell, Notts, they might be able to get some RLC's for you. I got mine up at Fishinc in Sheffield, but I don't think they have any more.