A mass recruitment event in the land crab Gecarcinus ruricola (Linnaeus, 1758) (Brachyura: Grapsoidea: Gecarcinidae), and a description of the megalop

Abstract

A mass return to land of the megalop of the land crab Gecarcinus ruricola is reported. The return occurred in June 2004 on the island of Providencia in the western Caribbean: this is the first detailed report of larval return in this species, and the most detailed report for any gecarcinid. Crabs emerged from the sea as megalops over 2 to 3 days, and moved rapidly landwards. Vast numbers migrated >50 m across land before moulting to the first crab - the megalop is clearly the invasive stage. The megalop is described for the first time, and criteria are identified to discriminate it from other Caribbean gecarcinids. © 2006 The Linnean Society of London.