La Stridulation Chez Les Crabes

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

“…Decapod crustaceans possess a wide variety of morphological features that could potentially generate auditory signals (Guinot- Dumortier & Dumortier 1960). The 2 primary modes of stridulation are believed to be friction of appendages against the cephalothorax or friction of appendages against other appendages (Guinot-Dumortier & Dumortier 1960).…”

“…The complexity of the social behaviour in these sesarmids suggests that some form of intricate communication system exists (Seiple & Salmon 1982). Although the emphasis of studies on grapsoid crab (including sesarmids) communication has been on visual displays (Schöne 1968, Huang et al 2008, given their gregarious nature and the presence of potentially sound-producing morphological structures in many species (Guinot-Dumortier & Dumortier 1960), the use of acoustic signals may be expected.…”

“…Semiterrestrial crabs produce sound by a number of methods (von Hagen 1975): (1) respiration, the movement of fluid across an orifice; (2) convulsion, the free vibration or quivering of appendages; (3) percussion or rapping, the striking of a body part on the substrate; and (4) stridulation or rasping, a file-and-scraper mechanism involving the appendages and/or the cephalothorax (Guinot-Dumortier & Dumortier 1960, Salmon & Horch 1972 where the file (pars stridens), a surface of ridges or tubercles, is rubbed against a scraper (plectrum), which may be a protrusion with a tapering edge or a line of denticulations (Dumortier 1963, Clayton 2005. In general, it is the plectrum that moves against the pars stridens, but the inverse is not uncommon (Guinot-Dumortier & Dumortier 1960).…”

“…In general, it is the plectrum that moves against the pars stridens, but the inverse is not uncommon (Guinot-Dumortier & Dumortier 1960). Rapping and rasping are the most common modes of sound production in acoustic signalling in crabs.…”

“…Much less is known about the Sesarmidae. The presence of ridges on the chelipeds of sesarmids were previously reported (Guinot-Dumortier & Dumortier 1960), but any possible stridulatory function was dismissed due to doubts regarding the plausibility of reciprocal rubbing of the chelipeds (Ortmann 1901). However, rasping was subsequently reported in Sesarma reticulatum by Seiple & Salmon (1982, p. 6) who described it as 'self tapping' in which 'one claw [is] raised and brought down to make contact with the dorsal surface of the manus of the other claw'.…”