Ocellate Swimming Crab

Portunus sebae

Also known as the Spotted Swimming Crab. Easily identifiable. Their carapace can reach to about four inches across. Like other swimming crabs, their rear hind legs have evolved into paddles that are used for swimming and digging into the sand to hide.    They inhabit  reefs and hide in caves or recesses or under rocks ledges during the day. I was fortunate enough to see this specimen during a night snorkel. It was at a depth of about 2 feet. They are a True Crab.