Crab

Question
I just purchased 2 "Freshwater Fiddler Crabs" from walmart. The crabs were in a freshwwater aquarium, with no access to land, and had been living like that for a couple of weeks. I was wondering if they would be able to permanetly live that way. Thanks

Answer
Dylan,
I do not know of any fresh water fiddler crabs. These crabs are found on beaches and can either live in salt or brackish water. They will survive for a few weeks in fresh water but will soon become weak and die. It would be best to get a hydrometer and add enough salt to the water to attain a specific gravity of around 1.005 - 1.010. The package of aquarium salt may have instructions for producing brackish water conditions. It is okay to vary the salt concentration/specific gravity slightly as these crabs would naturally experience some variations in salinity. Your crab does need to be in both water and land. The best way to do this is to keep water on one side and slope the sand/gravel on the other side. You can also add rocks to one side. Whatever you need to do to allow the crab to either be in the water or on land.