Fiddler crabs are kept as exotic pets even though these crabs have short lifespan of 2-3 years in captivity. Fiddler crabs are from the Uca genus of crabs and are found in 94 different species. There are only 3 species which are native to USA, which are Mud fiddlers, Sand fiddlers and Red-Jointed fiddlers. Unfortunately, the already short lifespan is further reduced, because most pet owners are unaware of the proper steps involved in looking after these crabs. For one, the fiddlers are brackish animals which means that they can survive only in semi-salty water.
How to Look After Your Pet Fiddler Crab
1 - Tank Size
A aquatic fish tank with a capacity of 10 gallons or bit more will suffice and easily accommodate 2-4 crabs. So ensure that you buy a big enough fish tank for your fiddler crabs.
2 - Make Brackish Water
These crabs will die within a month if kept in freshwater. They need salty water to survive, breathe and feed through. Thus you will need to add 2 tbs (tablespoonfull) of sea salt for each gallon of water, which would be 20 tbs into the 10 gallon fish tank.
3 - Add Sand and Stones
Fiddler crabs will die very soon if they are not provided with a suitable surface to crawl on. They need sand or pebbles to keeping their grip while crawling on the beach. Similarly you will need to add ocean sand into the tank, and then add some pebbles all over the place. Make sure that the sand is slightly inclined so that you can make a burrow under the sand using a plastic box.
4 - Add a Filter
Use a strong filter which will keep the tank water clean and oxygenated at all times. Crabs are excellent climbers, therefore ensure that the filter is buried under the sand or under the pebbles.
5 -Temperature Heat Lamp
Because of their tropical origin, fiddler crabs prefer warmer waters and will die in cold water. The temperature will increase if a heat lamp is placed over the tank. A suitable temperature would be about 25-30 degrees Celsius.
6 - Dechlorinator
Natural ocean water does not have chlorine, therefore you will need to place a dechlorinator in the tank, so as to remove all traces of chlorine.
7 - Feeding
These crabs, while under captivity, will need to be fed algae tablets, which you can find in any aquatic pet store. They also enjoy feeding on shrimp, small fish, plankton and seaweed. Feed twice a day and in limited amounts.
8 - Tank Cleaning
The water will need to be replaced every once a month, as it will begin to look dirty. These crabs molt or lose their exoskeleton every 8 weeks, after which they will usually eat their own shell, in order to reabsorb the necessary calcium and iodine from it. During the phase of molting, the crab will remain hidden in its burrow.
It would be best to keep one female and a male fiddler together in one tank as this will increase the lifespan a bit more. Two male fiddlers living under one roof will constantly be fighting and will eventually cause the weaker crab to lose one of its claws! However if such a situation arises, you should not worry as the claw will grow back, while the intact claw grows even bigger than normal size.
No matter how much time you invest in fiddler crab care, these animals hardly ever seem to be able to live beyond a few months. The reason being that they are best suited for ocean waters and do not adapt well to an artificial environment.