A mangrove tree crab (Aratus pisonii) clings to a leaf near the Smithsonian Institution’s marine laboratory on Galeta Island, Panama, part of the Smithsonian Tropical Research Institute. During high tide, the crabs climb up into the branches and, during low tide, climb back to the mangrove tree's roots and freshly-revealed beach to scavenge for both plant and animal food, including bits of the mangrove trees it lives in.