[header] How to care for brackish water fiddler crabs (uca minax ) [title] Provide space. [step] Fiddlers need room, only two can fit in a 5 gallon (18. 9 l) aquarium and only four can fit in a 10 gallon (37.9 l) aquarium. So make sure you get the proper size aquarium. 
[title] Provide lots of climbing and hiding spots. [title] Provide the right environment for your fiddler crabs.