title: High e-vector acuity in the polarisation vision system of the fiddler crab Uca vomeris.
abstract: Polarisation vision is used by a variety of species in many important tasks, including navigation and orientation (e.g. desert ant), communication and signalling (e.g. stomatopod crustaceans), and as a possible substitute for colour vision (e.g. cephalopod molluscs). Fiddler crabs are thought to possess the anatomical structures necessary to detect polarised light, and occupy environments rich in polarisation cues. Yet little is known about the capabilities of their polarisation sense. A modified polarisation-only liquid crystal display and a spherical rotating treadmill were combined to test the responses of fiddler crabs to moving polarisation stimuli. The species Uca vomeris was found to be highly sensitive to polarised light and detected stimuli differing in e-vector angle by as little as 3.2 deg. This represents the most acute behavioural sensitivity to polarised light yet measured for a crustacean. The occurrence of null points in their discrimination curve indicates that this species employs an orthogonal (horizontal/vertical) receptor array for the detection of polarised light.
authors.affiliation: Sensory Neurobiology Group, Queensland Brain Institute, The University of Queensland, St Lucia, QLD 4072, Australia. m.how@uq.edu.au
authors.forename: Martin J
authors.initials: MJ
authors.lastname: How
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Pignatelli
authors.forename: Shelby E
authors.initials: SE
authors.lastname: Temple
authors.forename: N Justin
authors.initials: NJ
authors.lastname: Marshall
authors.forename: Jan M
authors.initials: JM
authors.lastname: Hemmi
mesh_terms: D000818:Animals; D003386:Brachyura / Q000502:physiology*; D005260:Female; D008027:Light; D008297:Male; D008954:Models, Biological; D010775:Photic Stimulation; D014785:Vision, Ocular