Red Clawed Crab ?'s

The outer shell splits open, and the crab crawls out. A new shell has been developing underneath the old one, but it is very soft while new. Since this leaves the crab very vulnerable, it will hide in a crack, or cave while the new shell hardens. A soon as the shell hardens, the crab emerges, bright and shiny.

If the crab can't find some where to hide, fish or other crabs may kill it. The mineral content of the water must be able to supplement the hardening process--I am not sure what all it needs, but know that without the right minerals the shell won't herden properly, which can kill them.

GL

the best info i found on RCCs is here http://wrongcrowd.com/aquaria/crab/

Another place for RCC info is:
http://www.geocities.com/elgecko1989/crab.html