A harlequin swimming crab (Lissocarcinus laevis), lives with this sea anemone in symbiosis, Philippines, Southeast Asia, Asia

A harlequin swimming crab (Lissocarcinus laevis) hides under an anemone, Wakatobi National Park, Indonesia.

A harlequin swimming crab (Lissocarcinus laevis) sits on the seafloor of Lembeh Strait, Indonesia.

A mother sea otter (Enhydra lutris) eating a Dungeness crab with her pup in the Inian Islands, Southeast Alaska, United States of America, North America

Swimming Crab (Liocarcinus depurator), legs spread out, viewed from above showing swimmerettes on hind legs, sandy seabed, St Abbs, Scotland, UK North Sea

Velvet Swimming Crab (Necora puber) in anemone. Babbacombe, Torquay, South Devon, UK Restricted resolution (Please contact us). (RR)

Velvet swimming crab (Liocarcinus puber), St Brides, Pembrokeshire, Wales, UK, Europe (rr)

Brown Swimming Crab (Liocarcinus navigator), clear view of crab showing colour and shell markings, St Abbs, Scotland, UK North Sea

Velvet Swimming Crab (Necora puber), viewed from above, crab is hiding under rim of anemone's colourful tentacles, St Abbs, Scotland, UK

Brown Swimming Crab (Liocarcinus navigator), clear view of crab showing colour and shell markings, St Abbs, Scotland, UK North Sea

Velvet Swimming Crab (Necora puber), view showing underside, dark tipped claws and brilliant red eyes, St Abbs, Scotland, UK

Brown Swimming Crab (Liocarcinus navigator), clear view of crab showing colour and shell markings, St Abbs, Scotland, UK North Sea

Velvet swimming crab (Liocarcinus puber) positioned in a crevice. UK.

Velvet swimming crab (Liocarcinus puber), St Brides, Pembrokeshire, Wales, UK, Europe

Brown Swimming Crab (Liocarcinus navigator), clear view of crab showing colour and shell markings, St Abbs, Scotland, UK North Sea

Brown Swimming Crab (Liocarcinus navigator), clear view of crab showing colour and shell markings, St Abbs, Scotland, UK North Sea

Swimming crab, Charybdis acutifrons, Gato Island, Cebu, Philippines.

The Blacktail Snapper (Lutjanus fulvus) reach 13 inches in length and feed mostly on small fish and crabs. This is one of several species that were sucessfully introduced to Hawaii, Hawaii, United States of America

The Hawaiian Swimming Crab (Charybdis hawaiensis) adult is about 3 inches across it's carapace, Hawaii, United States of America

Channel-clinging crab foraging for food in a marine reserve.

Red-legged Swimming Crab, Portunus convexus, Djibouti, Djibuti, Africa, Afar Triangle, Gulf of Aden, Gulf of Tadjourah

Red-legged Swimming Crab eating fish, Portunus convexus, Djibouti, Djibuti, Africa, Afar Triangle, Gulf of Aden, Gulf of Tadjourah

Scuba diver and Spider hermit crabs in anemone, Stenorhynchus seticornis, Netherlands Antilles, Bonaire, Caribbean Sea

Mating Swimming Crab, Portunidae, Micronesia, Palau

Red-legged Swimming Crab eating fish, Portunus convexus, Djibouti, Djibuti, Africa, Afar Triangle, Gulf of Aden, Gulf of Tadjourah

Red-legged Swimming Crab, Portunus convexus, Djibouti, Djibuti, Africa, Afar Triangle, Gulf of Aden, Gulf of Tadjourah

Red-legged Swimming Crab, Portunus convexus, Djibouti, Djibuti, Africa, Afar Triangle, Gulf of Aden, Gulf of Tadjourah

Red-legged Swimming Crab eating fish, Portunus convexus, Djibouti, Djibuti, Africa, Afar Triangle, Gulf of Aden, Gulf of Tadjourah

Swimming crab (Cronius ruber). Newly cited species in the Canary Islands (2015). Due to its large number of observations it is considered invasive. Marine invertebrates of the Canary Islands, Tenerife.

Great Black-backed Gulls with a comb in the beak, France