Return to the land; the stages of terrestrial recruitment in land crabs

The stage at which land crabs of the Gecarcinidae recruit to land is examined, and discussed in relation to recruitment in other terrestrial crabs. New data are presented for species of Johngarthia, and published data on other species are re-examined and evaluated. The gecarcinids Gecarcinus and Johngarthia appear unique in that the megalops migrates inland into fully terrestrial habitats before moulting to the first crab instar. In other land crabs, so far as is known, the moult to the first crab occurs either in the water, or in moist adjacent habitats.