my crab... F, really BW... color change... beh.  – 06/12/09
Dear Crew;
I have a red clawed crab that I have had for almost 6 months now. He always seems pretty happy and forages around a lot for food. I feed him shrimp pellets and the odd tiny piece of orange (which he attacks and drags into his cave to devour). Today I looked at him and he has suddenly gone really red. I mean really red: his legs, his chest, and even some of his back. The little guy has molted twice now and I don't remember the colour change. He seems really active, the water is clean, I don't know if something is
really wrong, or really right. Can you help me?
Thanks!
Rachel
<Hi Rachel. It's difficult to know whether or not what you're seeing is normal, and the best approach with crustaceans generally is to focus on preventative healthcare. We know precisely what Perisesarma bidens needs to do well: an aquarium with dry land to explore; marine aquarium iodine added at half the normal dose; and brackish rather than freshwater conditions, 6 to 9 grammes of marine salt mix per litre of water being adequate. If you do all these things, your crab should be in good health. If you're not doing all of these things, then it's possible you're seeing some sort of negative reaction. If he's active, that's a good sign, so if you correct conditions in the tank, hopefully he'll settle down and have a healthy life. Cheers, Neale.>

Re: unknown crab, fdg., sys., beh.   4/22/09
Neale,
I was mistaken when I said that the crab had eaten a nice piece of cantaloupe.
<Banana! Land crabs seem to love banana, the softer the better! Also try small pieces of white fish, ideally lancefish, which you can buy in pet shops. These have bones in them, and the calcium there is excellent for the crabs. Unshelled prawns, perhaps sliced along the middle to make things easier, are also a good source of calcium. Crabs are scavengers, and generally eat anything that's soft or meaty.>
My wife had removed it as it was getting a bit smelly. The crab has not eaten anything since we got her and has seemingly become very weak.
<Review air temperature and humidity; these are essentially like frogs in terms of care, and cold, dry air does them no good at all. Turning the heater up in the water side of the tank can create more warm, humid
conditions in the land side of the tank. Likewise, keeping the lid more firmly secured will help, too.>
She has not moved much in the past 2 days. Maybe she's getting ready to molt.
<You can actually check this: before they moult, crustaceans absorb extra water. When picked up, you may notice they've both bulked up and yet the shell is softer than normal, and may even yield a bit to the touch. They feel less heavy for their size that you'd expect (a tip you using when buying edible crabs, by the way). While the following link refers to Land Hermits, in terms of generalities, it would hold true for Land Crabs too:
http://hermit-crabs.com/molting.html
So, prior to moulting, the crab will puff up, become softer, tend to hide away from light, and generally become inactive. Moulting starts with the exoskeleton unzipping, and the crab sort of backs out of its shell,
tail-end first.>
I hope so. We would not feel like very good stewards if she dies.
<I understand!>
Already lost one pet this week :-( One of our Fischer's lovebirds had a seizure and died in my hands.
<Oh, sorry to hear that.>
Of course, I have zero history on the crab. Have tried feeding her a variety of foods to no avail. Any suggestions? Thanks.
Quick
<Cheers, Neale.>