Episesarma is a genus of swimming crabs species in the family Sesarmidae. Wikipedia
Features: Body width 4-5cm. Body flat and squarish, legs flat with pointed tips. Pincers may be colourful. The sides of the body have a structure with a net-like pattern that help recirculate and oxygenate water in the gill chambers. In this way, these crabs can breathe air and stay out of the water for some time. WildSingapore
Spotted at Sungei Buloh Wetland Reserve