Facts and Information

Often sold as "Mini Crabs" in the aquarium trade, these little crustaceans are members of the Ocypodinae family and are included in the Uca genus, which includes over ninety known species so far. One unique trait of these crabs is having an asymmetric cheliped, or one claw that is significantly bigger than the other one. This in only present in the males of the species, and their larger claw (usually the right one) can easily exceed their body length. This huge claw is used for posturing to ward off other males and attract the attention of females. All the species of Uca crabs are found along coastal areas in grassy marshes or intertidal areas. Burrows are dug into damp sand or mud and the crabs are quick to retreat when danger is about. The eyes of a fiddler crab sit atop stalks that retract into grooves in the shell and allow the crabs to see in all directions, at the same time! All crustaceans should molt regularly, or shed their exoskeleton. When they do, it should be left in the tank as the crabs will eat it within a week or so and will reabsorb the calcium and nutrients of the shed.
PH Levels - 7.2 to 8.4
Hardness Levels - 210 to 320 ppm
Temperature - 75 to 82°F
Size - Small
Possible Tankmates - Zebra Danio, Black Molly