Can I keep crabs?
Keeping crabs is a different story than keeping crayfish and shrimp.
Crabs are very nice and pretty animals and are ideally kept in a special aquarium. Some smaller species (Sesarma bidens) are being kept in communnity tanks. Crabs have the tendency to eat plants and grab fish when they get the chance. Crabs come in many different kinds. Species as well as coloration and behavior.
Crabs need reasonably hard water because the molt. The outer shell which is left in the water will be eaten again.These shells contains calcium and chlitine and is used to help built the new outer shell. Crabs are subdivided into different families. A few families which are commonly traded and bred:
More different families exist but these are usually not available on the market. These are the most common types available.
Some kind need little to no land area while others can mostly be found on the land.
Always make sure there is land available by means of a small sand beach or some wood outside of the water. Crabs will make use of it frequently.
Crabs of the genus Uca are so called fiddler or calling crab and have an average size of 7cm. The male crab always has one big claw. Crabs of the Cardisoma genus are true climbers and extemely strong. An adult crab can easily lift the lid of the aquarium. The can grow up to 15cm, in the wild even bigger. The (Geo)sesarma are smaller crabs and grow up to approximately 4cm and are the easiest to keep. Just like all crabs they eat virtually anything. For all crabs you have to make sure the lid is always closed properly in order for the crabs not to escape.