Sand crabs are tiny invertebrates that live in shifting sand. If you’ve spent any time at the ocean, you probably have seen the small creatures burying into the swash zone, where the waves are breaking. Though small, sand crabs' tails have the largest sensory neurons of any animal. If you capture a sand crab from the ocean and take it home, proper care is essential.
Fill a 5-10 gallon fish tank with aquarium sand. Heat the tank to 75 degrees with an undertank heater. Maintain this temperature--ideally at 70 percent humidity--to mimic the natural conditions that your sand crab is used to. Put a wet sea sponge into the tank to increase the humidity if the environment does not naturally sustain a 70 percent humidity reading.
Place your sand crabs into the tank and allow them to get used to their new home by burying themselves into the substrate.
Furnish the tank with driftwood, artificial plants and coral. Sand crabs like to keep busy and enjoy climbing. Change the location of the items periodically to keep the sand crabs busy and engaged.
Place a shallow dish of fresh water into the tank. Check to make sure the bowl remains filled because sand crabs need plenty of fresh water.
Feed your sand crabs plankton, which you can find in a sand crab food supplement from the pet store.