The Blue Swimmer Crab (Portunnus pelagicus) is a large crab species that belongs to the ‘Swimming crabs’ family Portunidae. It can be found around the entire Australia coast and is also known to occur in the Indo-western Pacific region and the Mediterranean Sea. The males are generally a mottled blue colour whilst the females have mottled brown however the intensity and pattern of the colouration is very variable. They can be found in coastal estuaries and embayments and are found on sandy/silty bottoms and in amongst seagrass meadows. They are good eating and are sought after by commercial and recreational fishers. The Blue Swimmer Crab (Portunnus pelagicus) has a maximum carapace width of approximately 21cm.