How long can fiddler crabs go without food?
Fiddler crabs can go as long as a month without food, but will eat every day if food is available.
Fiddler crabs come from the mangroves where there may be a regular fresh water flush so they may survive for a short while in fresh water. They will not however be able to live for long because they need the calcium and other elements in sea water in order for them to get the neccessities for shell growth.
Hermit crabs can live for some time without water however it is not recommended and the more time that they are without water the more suceptible they are to disease and death. i have seen crabs live for over a month without water but most do not survive long after that, even when the are moved to ideal surroundings.