Odd freshwater Crab behaviour
I have a ten gallon tank with low water and rocks for crabs and other crustaceans. I bought some crabs and here's my q's.
One: Are the crabs with one large and one small claw  males, and the ones with two small claws females?
Two: Today the male??, one large one small claw, climbed out of the water onto the rock and started foaming? or bubbling from his face and doing something, like he was washing?? what is this? He the proceeded to sit then later he did this crazy claw dance, waving his arms around slowly in these rhythmic motions all the way out and then back in, what the heck? Does he have mad crab disease?
Three: I put in feeder golds but they seem to ignore them. so I feed blood worms. should I add plants for veg food, or just stay with blood worms and whatnot?
Four: The red crab I got has only one claw will his other grow back like at molting or something?
Five: What's the ratio on crabs? The same as fish or?
i tried here and all over to find good info on their behaviour and i came up empty handed!
>> Yes, crabs with one larger claw are more likely males in most species. Crabs have to get oxygen when they are out of the water they will "chew" a small amount of water to mix it with air and get oxygen from this process, that is likely why your crab is foaming. He is waving his claws to show his territory and attract females, so he is not mad. You can feed with bloodworm, but try other foods to see what else your crabs will eat, it varies from one species to another, but most are omnivores. The missing claw should be replaced in the next molt,  I would not worry. For a great website on crabs and other crustaceans check http://www.crusta10.de not sure if it is all in English, but the site owner is one of the most knowledgeable people on the subject. Good Luck, Oliver

Anomalous Crab Question - 10/30/2004
Hello, My little red crabs keep getting on the filter and just sit there like they are in a stream.
<Er, do you know what kind of crabs these are?  Can you give me a good description of them?  Size, coloration, markings, anything like that?>
I do not see how they are getting up there unless they can swim. Why and how do you think that they are doing this?
<The how is the easy part.  Crabs are *amazing* for being able to climb nearly anything....  I wouldn't be too terribly shocked if they were simply climbing the glass!  But more likely, they're finding a way up to the filter intake tube, and climbing that.  Now, as for the "why" of it, there are likely a few reasons.  First, is this a fresh, brackish, or saltwater aquarium?  In what country do you live?  In the US, there are nearly - or absolutely - no crabs sold in the hobby that are truly freshwater animals.  Most will survive in freshwater for a time, but they will not thrive and will not live their full life span.  Moreover, nearly - or absolutely - no crabs sold in the trade in the US are truly aquatic.  All are amphibious, or land crabs that only occasionally venture into the water.  Chances are, your little inverts are just trying to find a way out of the water.  At the very, very least, I recommend you drop the water level a bit, and give them a surface to rest on out of the water.  Try to provide them with a few hidey-holes on the surface to help them feel secure.  Remember, crabs are extremely adept escape artists, and they can and will find any way out of the tank, especially if they're not happy with their setup.  Please be sure you have a tight-fitting lid, or you might wake up in the morning to find a crab cuddling you in bed!  ;) >
Thank you
Kayce
<Wishing you well,  -Sabrina>

Molted Crab - 05/31/2004
I have a Red Claw Crab, he is my first crab and I don't know what to do now that he has molted. His old shell/skin is sitting at the bottom of my tank, I don't know if I should remove the skin or leave it in the tank.
<I would leave it.><<Often are eaten, reincorporated into new exoskeletons... necessary mineral content. RMF>>
I know Hermit crabs need their old skin to eat, but I don't know what to do with this one.
<If it's not gone in a few days, pull it out.  I would assume the crab (or other denizens of the tank) will have made short work of it, by then, but if not, best to get it out.  Wishing you and your crab well,  -Sabrina>
Shelly Warren