Common Name: Rainbow Crab, Halloween Crab, Rainbow Land Crab,
Halloween Land Crab, Land Crab, Soapdish Crab

Scientific Name: Gercarcinus sp

Origin: Central and Northern South America

Maximum Size: 5" - 6" Legspan

Care: Not too simple... A typical RLC requires a 20 Gallon long tank minimum, filled with a sloping bank of sand which at the deepest point is 8".I've been recently notified that they are in fact, freshwater, contrary to what I have learned from various sites. They also need cuttlebone for calcium supplementation. These lil' guys live anywhere from 10 - 20 years. (with proper care)

Temperature/Humidity: Crabbie likes it rather toasty, somewhere around 75ºF - 85ºF. Sub-Tropical to Tropical conditions. That pool of water should do the trick.

Feeding: I've got a balanced 8 part NATURAL diet for mine, you're welcome to use it. They are not the most finicky of eaters either. They don't eat much either, so you can mix it in a five gallon bucket. Oh and trust me, IT MUST BE REFRIGERATED. You'll read why.

Rainbow Crab Food

6 oz. of dried krill
8 oz. of Algae Wafers
3 thinly sliced, cleaned carrots
6 chopped feeder goldies (trust me, the lfs will have recently deceased ones)
5 dehydrated apple slices
7 oz. almonds(unsalted)
6 oz. dried brine shrimp
5 oz. dried bloodworms

Then add dechlorinated water.

Handling..... Not the best of ideas... pinchy pinchy.... hard!

Additional info: There's a reason they're call soapdish crabs. They have to ship them that way, because... What's the best way to phrase this... Think of them as the Bettas of the crustacean world. They will kill each other, and then eat each other, and then... You get the deal. ONE PER TWENTY GALLONS! You won't regret it. Neither will the weaker of the two crabs.

This post has been edited by The_Dude: Oct 6 2007, 01:59 PM

Ive kept this species for years, my ones has always been in freshwater, not at all brackish, and are fine, they have both shed around 6-7 times now, always successfully, the largest is around 15-18cm across, they were both tiny when I first got them.

I feed my ones mainly fruit, Banana, apple etc.. The water area is around 6 inches deep, the substrate (of sand/coir/fine gravel) slightly deeper at around 8 inches, the water is heated to 26c and is filtered.

Also, are you sure they come from South America? I was under the impression they were from Nigeria, as it also states in the practical fishkeeping caresheet

http://www.practicalfishkeeping.co.uk/pfk/...?article_id=426

Another species commonly kept in captivity, Gercarcinus sp are refered to as Halloween Crabs, they are from Central and South America.

I was under the impression that they were brackish, and if they're not, I need to go change the care of mine. Also, I've read on several sites that they were from Africa and another species of similar size and coloration in central and south america requiring almost identical care. I've gotten my scientific name wrong before, but thank you. I'll look into it.

Im sure brackish water would also be fine for them, like most Land Crabs, its just ive never kept my ones in brackish water, and they've been more than fine for years, and are both a good size now, the one of them especially is huge, the smaller one shed its skin earlier this week.

There are South American Cardisoma species, one of them is Cardisoma guanhumi, which is very similar to C. armatum, especially when young, but is more of a blue colour when adult, it gets massive though, much larger than armatum. Its care is also the same as the African species, I should be getting them soon, along with a few other South American species.