Appearance
Carapace of Dardanus arrosor can reach a length of 6–8 centimetres (2.4–3.1 in). The color varies from bright red to bright orange. The eyestalks are robust, not very long, dilated at the tip and alternately streaked with red and white. The eyes are bluish. Claws show hair-like spines and warty tubercles. The left claw is more developed than the right one, but in both claws the tip is black or yellowish. The abdomen is asymmetrical, bare and hidden within a shell.