Compressed Fiddler Crab (Tubuca coarctata)

Crabs are arthropods that are part of the subphylum Crustacea. I found these fiddler crabs (Tubuca coarctata) while walking in the mangroves a few days ago. Thousands of fiddler crabs appear during low tide along the brackish river in the mangroves and along the coast. I caught two crabs: one was a juvenile fiddler crab and the other was an adult. Both are male, as seen from one of their large claws. Unlike the females, who only have a pair of small claws, and are smaller than the males.