Ryan Photographic - Portunidae - Swimming crabs
The family Portunidae is one of the most speciose of the crustaceans with 603 species in 42 genera. The family is characterised by the possession of a flattened paddle-like fifth pair of walking legs which gives them swimming ability unparalleled amongst the crabs. Large mangrove crabs (Scylla) use the paddle for rapid digging in mud. The Portunidae includes several economically important species including the blue crab and the mangrove crab. Some species live commensally on other species. They are widely distributed in shallow water in temperate and tropical oceans.
Lissocarcinus laevis Harlequin swimming crab
Lissocarcinus laevis Harlequin swimming crab, Rao Island, Morotai, Indonesia
Lissocarcinus orbicularis Sea cucumber swimming crab
Lissocarcinus orbicularis Sea cucumber swimming crab, Lembeh, Indonesia 5P7A7588
Portunus pelagicus Blue swimming crab
Portunus pelagicus Blue swimming crab, female Magic Bay Rao, Morotai 5P7A7658