Teardrop Crab Inside a Sponge

Photograph by Paul Sutherland, National Geographic

A cryptic teardrop crab (Pelia mutica) seeks refuge inside a sponge near Bonaire Island in the Caribbean. Relying on camouflage, the crab's bright red carapace averages only 0.5 inches (1.3 centimeters) in length and can be covered by tunicates or sponges.