Blue Swimmer Crab also known as Flower Crab, Blue Crab, and Blue Manna Crab, are large crabs found in the intertidal estuaries of the Indian and Pacific Oceans (Asian coasts) and the Middle-Eastern coast of the Mediterranean Sea. The males are bright blue in colour with white spots and characteristically long chelipeds, while the females are a duller green/brown, with a more rounded carapace. The carapace can be up to 20cm (7.9in) wide.