The uca crab (fiddler crab), commonly known as calligrap crab, is commonly found along seashore and mud plains between the brackish tides, lagoons and swamps. The most famous fiddler frozen with its dimorphic sexual claws: The male main claw is much larger than the female while the male and female nails are the same size.
The large claws possessed by the male fiddler crab were used to communicate, specifically to attract the attention of female crabs. Another striking difference is the shape of the stomach (pleon). almost all male Uca crabs have narrow and triangular-shaped pleons, while female crabs have a wider and rounder pleon. It is demonstrated that female crabs incubate fertilized eggs in pleopod.
