Land Crabs on Ascension
The Land crab ( Johngarthia lagostoma ) is a species of which is found on Ascension. This species is only otherwise found on three small Brazilian islands – Trinidade, Atol de Rocas and Fernando de Noronha. Land crabs evolved from marine ancestors and now inhabit terrestrial environments. They are still linked to the ocean as they must migrate to the shore to release eggs into the sea and the eggs hatch in the water (spending a brief period as zooplankton) before emerging onto the land to spend the rest of their lives on terrestrial ground. The land crabs on Ascension are also the second largest native animal found here on Ascension. Land crabs are important keystone species of island communities as predators, litter controllers and seed dispersers. Through these functions they form a key part in the food web and help cycle nutrients through the environment. Land Crab Surveys There are three possible origins of the land crabs on Ascension – America, Afric