Gelasimus

Common Names

Fiddler crabs are commonly known as fiddler crabs, due to the males' large claw which resembles a violin. They are also known as "calling crabs" because the waving motion of the large claw is reminiscent of a fiddler playing a violin. Other common names include:

• Violin crabs
• Fiddler crabs
• Calling crabs
• Sand crabs

Characteristics

Fiddler crabs are characterized by several distinctive features, including:

• Asymmetrical claws: Males have one large claw that is significantly larger than the other. This large claw is used for display, fighting, and attracting mates. The smaller claw is used for feeding.
• Brightly colored claws: The large claw of the male is often brightly colored, with colors ranging from red to orange to blue.
• Small eyes: Fiddler crabs have small eyes that are located on stalks, allowing them to see above the surface of the water.
• Flattened body: The body of a fiddler crab is flattened, allowing it to move easily through the sand.
• Burrowing behavior: Fiddler crabs dig burrows in the sand or mud, which they use for shelter and to escape from predators.

Environments

Fiddler crabs are found in intertidal zones and mangrove forests around the world, especially in tropical and subtropical regions. They prefer areas with soft sediment and plenty of food. They are often seen in large groups, called "fiddler crab colonies," and are an important part of the marine ecosystem. Fiddler crabs feed on algae, detritus, and small invertebrates, playing an important role in nutrient cycling.

References

You can find reliable information about Gelasimus from the following sources:

• World Register of Marine Species (WoRMS)
• National Center for Biotechnology Information (NCBI)
• ScienceDirect