Ingo Arndt / Blue Crab (Discoplax hirtipes) with claws raised in defensive / aggressive posture, endemic to Christmas Island, Indian Ocean, Australian Territory

Ingo Arndt / Blue Crab (Discoplax hirtipes) with claws raised in defensive / aggressive posture, endemic to Christmas Island, Indian Ocean, Australian Territory

Adrian Davies / Blackback land crab (Gecarcinus lateralis) dragging leaf into burrow, Barbados.

Pete Oxford / Blue Land Crab (Cardisoma guanhumi) male, Banco Chinchorro, Yucatan Peninsula, Mexico

Ingo Arndt / Blue Crab (Discoplax hirtipes) in defensive posture, Christmas Island, Indian Ocean, Territory of Australia

Heather Angel / Land crab crawling on red sandstone after overnight storm. Shunan Zhuhai National Park, Sichuan Province, China.

Piotr Naskrecki / Brown Land Crab (Cardisoma carnifex), Vamizi Island, Mozambiqiue

David Fleetham / Land crab (Gecarcinidae) pausing just above high tide mark, Savusavu, Fiji.

Kevin Schafer / Purple Land Crab (Gecarcinus ruricola) juvenile, Zapata Peninsula, Cuba

Luis Quinta / White forest crab (Cardisoma armatum) Island of Principe UNESCO Biosphere Reserve, Democratic Republic of Sao Tome and Principe, Gulf of Guinea.

Luis Quinta / White forest crab (Cardisoma armatum) portrait, seen through claw, Island of Principe UNESCO Biosphere Reserve, Democratic Republic of Sao Tome and Principe, Gulf of Guinea.

Luis Quinta / White forest crab (Cardisoma armatum) Island of Principe UNESCO Biosphere Reserve, Democratic Republic of Sao Tome and Principe, Gulf of Guinea.