Mud crabs can be a nice alternative to the more common pet hermit crab. They are very hardy animals and are tolerant to a variety of water conditions. When setting up a proper tank, one crab will do fine in a 20-gallon aquarium, but may outgrow the small setup; these crabs average 9.5 to 11 inches long, so if you have multiple mud crabs, you'll want a larger aquarium.
Set Up the Enclosure
Add 2 to 3 inches of gravel or sand to the bottom of the aquarium. Fill the aquarium with salt water to a depth of about 6 to 10 inches. Mud crabs are bottom feeders and won't utilize the entire aquarium, so there's no need to fill it to the top.
Attach the filter and oxygen pump. Most likely, the filter and oxygen pump will not be fully submerged, so you'll need to pour salt water through the system. Turn it on to ensure it will run properly before the crabs are added.
Decorate the tank with caves and rocks to provide shelter for the crabs. If possible, add decor that will reach above the water level so the crabs can climb up if they feel they need. Plants aren't necessary, but you can add them as a source of food or for aesthetic purposes.
Add your crabs and watch how their behaviors. You'll find they are most active at night, so you'll want feed in the late evening hours in order to observe their feeding behaviors. A proper diet for mud crabs include shrimp, snails, feeder fish or one of the many commercial crab diets that are available at most pet stores, such as shrimp pellets or sinking tablets.
- Ideal salinity is 10 to 20 parts per thousand.
- Mud crabs are scavengers and will eat just about anything, but without sufficient food, mud crabs will become cannibals.
- You will most likely not need an aquarium heater, as the tank can be maintained between between 68 and 90 degrees Fahrenheit.