In the Galápagos, Crabs Hitch Rides on Iguanas
by Owen James Burke
“Crabbing a Ride.” Fernandina Island, the Galápagos. Photo: Nancy Leigh/National Geographic Your Shot.
The relationship here has been observed on several occasions, and is said to be a cleaning symbiosis between the “Sally Lightfoot” (Grapsus grapsus) and the marine iguana (Amblyrhynchus cristatus), unique to the Galápagos.
The “Sally Lightfoot”, or red rock crab feeds off of the dead algae on the iguana’s skin, and the iguana is then able to forego the inconvenience of having to maintain its own hygiene. Where can I get one of these things?
“The setting was very eerie,” writes Your Shot member Nancy Leigh. “In the darkness [of] an overcast early morning, there was a large gathering of black juvenile iguanas on the rocks of Punta Espinoza on Fernandina Island in the Galápagos.” While completely surrounded by iguanas, Leigh spotted a bright-red Sally Lightfoot crab climbing onto one of the lizards. “It was a delicate balance … acting fast to capture the moment while respecting their space and not disturbing either animal,” she says.
Browse more Your Shot photographs on NatGeo. -OJB