Tropical Fish Tank Species Profile: The Mischievous Fiddler Crab

While most people have seen video of fiddler crabs on TV as they scour the beach with their distinctive oversize claw and beady eyes, not many people realize that they can kept in freshwater fish tanks as pets.

Hermit crabs are definitely the most popular crab species in terms of amount owned as pets, but fiddler crabs can be found at numerous pet and tropical fish stores across America and usually go for a fairly low price of 2-5 dollars each. They are a little more demanding and difficult to take care of than other bottom-dwelling fish species such as the lobster-like crayfish and shrimps for example, but the humor and intrigue they can add to your tank are worth it in the long run.

The first thing you should look for in a fiddler crab at a pet store is one that is constantly on the move and active, and one that has a large claw. These are signs of physical health. Only the males have the giant claw, but most pet stores sell males only anyway so if you see one without a large claw you should probably stay away from it.

Next, you need to find out how long the crabs have been at the store for by asking an employee. Fiddler crabs don't survive as long as other species in freshwater because they prefer a little bit of salt water in their living environment. The problem with this is that most stores keep them in a classic freshwater tank set up and don't mention this fact to customers. That's why you want crabs that have recently arrived in the store and not ones that have been sitting in freshwater already for weeks.

From this point on you need to decide how long you want to keep the crabs for in your tank. If you want to keep them for longer than just a three to six weeks or so, you'll need to add a little bit of saltwater to your tank. For this reason it is a good idea to keep them alone in their own tank or with other similar species if you do decide to add salt to the tank. You won't need a complete saltwater tank set-up for these crabs, you only need to add a little salt to the water to make it brackish. To find out how much salt you'll need, buy a hydrometer at the pet store (they're fairly cheap) and hydrometer and add enough salt to to hit a specific gravity level of around 1.005 - 1:010.

Feeding is simpler, however, as the crabs enjoy sinking crab food or shrimp pellets as well as freeze-dried shrimp. Try and keep bottom-dwelling fish species out of the tank, however, because the crabs will not be shy about eating them.

Finally, you'll need to set up your tank in a way that keeps the crabs secure so they don't crawl out and also gives them a little access to dry land in case they want to crawl out of the water for a while. Buy a large rock formation and only fill up the tank half-way or a little less while giving the crabs a nice little ramp area to come up and bask. Make sure you secure the top of the tank well so the crabs can't get out as well.

Take good care of your fiddler crabs and they will provide you with an entertaining change of pace that just might be the cure to the common fish tank.