Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) breeding male basking with Sally Lightfoot Crab (Grapsus grapsus) scavenging dead skin, Hood Island, Galapagos Islands, Ecuador

Michio Hoshino / Marine Iguana (Amblyrhynchus cristatus) group with Sally Lightfoot Crabs (Grapsus grapsus), Galapagos Islands, Ecuador

Tui De Roy / Sally Lightfoot Crab (Grapsus grapsus) pair sharing boulder with Marine Iguanas (Amblyrhynchus cristatus) to escape high tide, Mosquera Island, Galapagos Islands, Ecuador

Tui De Roy / Sally Lightfoot Crab (Grapsus grapsus) group sharing boulder with Marine Iguana (Amblyrhynchus cristatus) trio to escape high tide, Mosquera Island, Galapagos Islands, Ecuador

Tui De Roy / Sally Lightfoot Crab (Grapsus grapsus) group sharing boulder with three Marine Iguana (Amblyrhynchus cristatus) group to escape high tide, Mosquera Island, Galapagos Islands, Ecuador

Tui De Roy / Sally Lightfoot Crab (Grapsus grapsus) feeding along tide pool edge, Punta Espinosa, Fernandina Island, Galapagos Islands, Ecuador

Fred Bavendam / Horseshoe Crab (Limulus polyphemus) group crawling ashore on the high tides of spring to lay their eggs in Delaware Bay's sandy beaches, New Jersey

Sergio Hanquet / Sally lightfoot crab (Percnon gibbesi). Tenerife, Canary Islands.

Sergio Hanquet / Sally lightfoot crab (Percnon gibbesi). Tenerife, Canary Islands.

Sergio Hanquet / Sally lightfoot crab (Percnon gibbesi). Tenerife, Canary Islands.

Sergio Hanquet / Sally lightfoot crab (Percnon gibbesi) group. Tenerife, Canary Islands.

Sergio Hanquet / Gulfweed crab (Planes minutus), epibiont on Loggerhead turtle (Caretta caretta). Tenerife, Canary Islands.