Moulting Behaviour of Birgus latro

Abstract

THE moulting behaviour of Birgus latro, the coconut or robber crab, has never been described even though this crab has been the subject of many observations. Weins¹ reviewed these observations most recently, and Harms² reviewed the older literature. Neither moulting nor the moulting behaviour is mentioned in these reports with the exception of a photograph of a recently moulted B. latro by Harms. Furthermore, in several years of observation of B. latro in the Marshall Islands, exuviæ or freshly moulted crabs were never found although scores of burrows have been examined, often with the aid of local residents. Small individuals with a cephalothorax length of less than about 30 mm are relatively rarely found even when special efforts are made. Prof. Donald C. Matthews of the University of Hawaii has had similar experiences (personal communication, December 1962).