Fiddler crabs, also known as calling crabs, are known to be popular as pets! Besides their unique appearance, the fact that they show better adaptability with other crabs and fish prompts many pet enthusiasts to opt for them. People even go out of the way to create a suitable environment for their pet fiddlers. Regardless of whether you have similar thoughts, or you are simply curious about the species, these facts about fiddler crabs will definitely be an interesting read.

Fiddler Crab Facts

Fiddler crabs are named so because of their large fiddle-shaped claw. These are the 100 odd crab species that belong to genus Uca of the Ocypodidae family. They are closely related to ghost crabs. Discussed below are some interesting facts about them.

When they eat their food with their smaller claw, it gives an impression that they are playing the fiddle with their larger claw. The marked difference in size between the left and right claw, which happens to be a characteristic trait of the species, is only seen in male fiddler crabs. Female fiddler crabs have two small claws. Males use their large claw to attract females and also to defend themselves against other crabs.

When a fight takes place, which is usually during the courtship period, males use their large claw to take on each other. They interlock their claws when they face each other in course of the bout. If one of them ends up losing the claw, which is very well a possibility, the small claw grows in size to become the large claw, while the lost claw grows back, but now it is smaller in size!

These crabs use their smaller claw for feeding purpose. They eat various types of algae, fungi, microbes, and other forms of decayed matter. (Hence, experts claim that they play a significant role in the environment.) They pick up chunks of sediment, but as it nears the mouth, the contents of the sediment are sifted through.

Besides their large claw, these crabs can be easily distinguished by their square-shaped body. Their coloration differs from one species to another. While mud fiddler crabs are brown in color, with the front portion of the shell having a shade ranging from basic blue to turquoise. The shell of the sand fiddler crab has a pink shade, with a patch of purple in between.

Fiddler crabs are generally seen in salty or marshy areas, sandy beaches, mangroves, and amongst stones and boulders at the beach. Geographically, they are most often known to occur on the shores of the Eastern Pacific, Western Atlantic, and the Indo-Pacific oceans.

There are many species and varieties of fiddler crabs as studied by experts. Some of the most popular species are ...
  • Mud fiddler crabs, which are found in marshy areas and feed on organic matter that is derived from the mud.
  • Sand fiddler crabs, which―as their name suggests, are found in sandy areas and on muddy banks.
  • Red-jointed fiddler crabs, which are found in freshwater areas, busy searching for food from the sandy substrate.
All these traits and functions probably make fiddler crabs interesting! So the next time you hit the beach, maybe you can observe them in person―their interesting habits in particular.