Chase Dekker / Sea Otter (Enhydra lutris) feeding on Dungeness Crab (Cancer magister), Monterey Bay, California

Agustin Esmoris / Crab (Cyrtograpsus angulatus), Argentina

Konrad Wothe / Sand Bubbler Crab (Dotillidae) on beach with sand balls, left-overs from feeding, Andaman Islands, India

Scott Leslie / Atlantic Rock Crab (Cancer irroratus), Bay of Fundy, Maine

Piotr Naskrecki / Crab (Potamonautidae), Gorongosa National Park, Mozambique

Cyril Ruoso / Short-tailed Crab (Potamocarcinus richmondi) in defensive posture, Barro Colorado Island, Panama

Piotr Naskrecki / Crab (Potamonautes sp) in defensive posture, Silaka Nature Reserve, Eastern Cape, South Africa

Christian Ziegler / Short-tailed Crab (Potamocarcinus sp) in defensive posture, Barro Colorado Island, Panama

James Christensen / Short-tailed Crab (Pseudothelphusidae) in defensive posture on forest floor, Mindo, western slope of Andes, Ecuador

Chien Lee / Cave Crab (Cerberusa tipula) endemic to the limestone caves of Gunung Mulu National Park, Malaysia

Fred Bavendam / Bat Star (Asterina miniata) group scavenging on dead Pacific Rock Crab (Cancer antennarius), Monterey Bay, California

Piotr Naskrecki / Crab (Liberonautes sp) in defensive posture camouflaged on forest floor, Mamang River Forest Reserve, Ghana

Thomas Marent / Arboreal Crab (Malagasya antongilensis), Masoala National Park, Madagascar

Thomas Marent / Arboreal Crab (Malagasya antongilensis), Masoala National Park, Madagascar

Thomas Marent / Crab (Madagapotamon humberti), Montagne des Francais Reserve, Antsiranana, northern Madagascar

Norbert Wu / Red Rock Crab (Cancer productus) pair mating with the female holding the male, Vancouver Island, British Columbia, Canada

Scott Leslie / Jonah Crab (Cancer borealis) hiding in sand, Nova Scotia, Canada

Scott Leslie / Atlantic Rock Crab (Cancer irroratus) hiding in sand, Nova Scotia, Canada

Scott Leslie / Atlantic Rock Crab (Cancer irroratus) on algae, Nova Scotia, Canada

Piotr Naskrecki / Short-tailed Crab (Fredius sp) can often be found outside of water, foraging on the forest floor, Guyana

Ingo Arndt / Edible Crab (Cancer pagurus) ten centimeters wide, Helgoland, Germany

Piotr Naskrecki / Squareback Marsh Crab (Armases cinereum) female, in the family of marine Rock Crabs (Sesarmidae), Costa Rica

Piotr Naskrecki / Arboreal Crab (Malagasya antongilensis) guards a tree hole in a remote forest of northern Madagascar

Piotr Naskrecki / Lobster Claw Crab (Liberonautes latidactylus) female, scouting the forest floor, Guinea, West Africa

Fred Bavendam / Rock Crab (Nectocarcinus integrifrons) eating a scallop, Edithburgh, South Australia

Fred Bavendam / Black Coral Crab (Quadrella maculosa) portrait, underwater, Manado, North Sulawesi, Indonesia

Norbert Wu / Graceful Rock Crab (Cancer gracilis) adult among sand flats, southern California

Fred Bavendam / Red-spotted Coral Crab (Trapezia rufopunctata) living among the stout branches of Cauliflower Coral (Pocillopora eydouxi), Bali, Indonesia

Fred Bavendam / Rock Crab (Nectocarcinus integrifrons) eating a scallop, Edithburgh, South Australia

Fred Bavendam / Splendid Pebble Crab (Etisus splendidus) photographed at night, Bali, Indonesia

Fred Bavendam / Red Rock Crab (Cancer productus) eating a Lion Nudibranch (Melibe leonina), Vancouver Island, British Columbia, Canada

Gary Bell/ Oceanwide / Black Coral Crab (Quadrella maculosa) on coral, Anilao, Philippines

Gary Bell/ Oceanwide / Boxing Crab (Lybia tessellata) holding sea anemones used for defense, Anilao, Philippines

Gary Bell/ Oceanwide / Boxing Crab (Lybia tessellata) holding sea anemone for defense, Bali, Indonesia

Gary Bell/ Oceanwide / Boxing Crab (Lybia tessellata) female with eggs holding sea anemone for defense, Bali, Indonesia

Piotr Naskrecki / Crab (Potamonautes gorongosa), newly discovered species, Gorongosa National Park, Mozambique

Scott Leslie / Atlantic Rock Crab (Cancer irroratus) and Acadian Hermit Crab (Pagurus acadianus) on kelp, Bay of Fundy, Maine

Mark Moffett / Socotra Freshwater Crab (Socotrapotamon socotrensis), Socotra, Yemen

Hiroya Minakuchi / Sand-bubbler Crab (Scopimera globosa) burrow and tracks in sand