Portunus pelagicus, also known as the blue crab, blue swimmer crab, blue manna crab and flower crab is a species of large crab found in the Indo-Pacific, including off the coasts Indonesia, Malaysia, Cambodia, Thailand, the Philippines, and Vietnam; and in the intertidal estuaries around most of Australia and east to New Caledonia.

Blue swimming crab or flower crab, Portunus pelagicus is an economically important species in tropical and subtropical oceans [ 18, 19 ]. Typically, the shallow bays with sandy bottoms are home to huge populations of this species [ 20 ].