
a. Area of chitinous ridges (fiddle) rubbed against b. ridge on the ischium (bow) to produce sound.
Note that the ridges on a are of two kinds, coarse and fine, giving the possibility of two tones.
This was going to be coming up later in the week, but couldn’t wait to share it once I read its label. The original beholder has noted that this cool crab used differently surfaced ridges to produce different tones of sound. Makes you wonder what they’re saying to eachother behind our backs! Ocypoda refers to the common name ‘Ghost Crabs’ which are so called because of their nocturnal behaviour and white appearance. Ghost crabs dominate sandy shores in tropical and subtropical areas, replacing the sandhoppers that predominate in cooler areas. Adult ghost crabs build burrows deep into the sand, where they reside during the hottest parts of the day. This particular species is characterised by a box-shaped body, 6–8 centimetres across the carpace, with a darker markings towards the rear in the shape of an H. (WARNING: this info is based on pages from Wikipedia, so may well be wrong).