Sound production and reception in mangrove crabs Perisesarma spp. (Brachyura: Sesarmidae)

Abstract

Acoustic signalling and sound production structures in the sesarmid crabs Perisesarma eumolpe (De Man) and P. indiarum (Tweedie) from Mandai mangroves, Singapore, were examined using 40 to 20 000 Hz sound recordings and scanning electron microscopy. The sound receptor, Barth's myochordotonal organ, was identified in both species. Only male crabs were found to display acoustically, and only during agonistic interactions. The present study also revealed key speciesspecific differences in the morphology of the stridulatory organs, stridulatory movements and resulting sounds produced. The findings show that acoustic signalling may be a significant component in the social behaviour of mangrove sesarmid crabs.