Dear Blue Lobster:
please help my fiddler crab is losing his legs!i just got him 2 days ago and he is eating and acting fine (except for his leg) i also keep him in a 10 gallon tank with 1 other male crab thank u
Dear Gentle Sir:
A 10 gallon tank may be too small to keep a pair of male fiddlers in. Just because the pet store does it doesn't mean that you should!!!
Other than stress created by suboptimal territory distribution between the two male fiddlers, here are a few other points to check up on:
Are the crabs being fed properly? Crustaceans are oppostunistic cannibals, and since these two males are kept closely together, territorial disputes may become occasions for quick meals.
What's the water like? Check pH, temperature, and nitrate levels, all of which can affect fiddlers. Also make sure that if you used tap water for your tank, you removed the chlorine or any other sanitary chemicals from it first.
Can the fiddlers get out of the water? In a 10 gallon tank, the water should be no higher than 3", with several areas the fiddlers can climb out of the water at. Fiddlers need air! Without access to air, a fiddler's health will decrease.
Hiding places! Like crayfish and lobsters, fiddler crabs molt. When molted, their hard exo-skeleton is shed off and they are left vulnerable for a few days while they recalcify their new exo-skeleton. Without a place to hide while so weak and soft, they can easily lose legs from competing fiddlers or any other predacious species in the tank.