Autotomy of the major claw stimulates molting and suppresses feeding in fiddler crabs

Abstract

Autotomy is a predator escape mechanism in many taxa, including crustaceans. Male fiddler crabs autotomize the major claw, despite its importance in mating, territoriality, and thermoregulation. This claw can be regenerated through molting. We investigated major claw autotomy in the fiddler crab Leptuca pugilator, testing hypotheses that (1) autotomy of the major claw accelerates the molting process, reflecting the importance of this appendage, (2) autotomy of the major claw results in increased feeding to accumulate energy reserves needed for regeneration, (3) this change in feeding is hormonally driven. Autotomy of the major claw accelerated molting. Yet contrary to expectations, autotomy of the claw initially inhibited feeding, with evidence for release of feeding inhibitory factor. These effects are specific to the major claw, and were not seen following autotomy of a walking leg. Acceleration of molting following autotomy of the major claw appears to be an adaptive response reflecting the costs of being without this multi-function structure.