title: Out of the blue: the evolution of horizontally polarized signals in Haptosquilla (Crustacea, Stomatopoda, Protosquillidae).
abstract: The polarization of light provides information that is used by many animals for a number of different visually guided behaviours. Several marine species, such as stomatopod crustaceans and cephalopod molluscs, communicate using visual signals that contain polarized information, content that is often part of a more complex multi-dimensional visual signal. In this work, we investigate the evolution of polarized signals in species of Haptosquilla, a widespread genus of stomatopod, as well as related protosquillids. We present evidence for a pre-existing bias towards horizontally polarized signal content and demonstrate that the properties of the polarization vision system in these animals increase the signal-to-noise ratio of the signal. Combining these results with the increase in efficacy that polarization provides over intensity and hue in a shallow marine environment, we propose a joint framework for the evolution of the polarized form of these complex signals based on both efficacy-driven (proximate) and content-driven (ultimate) selection pressures.
authors.affiliation: School of Biological Sciences, University of Bristol, Tyndall Avenue, Bristol BS8 1TQ, UK.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: How
authors.affiliation: Department of Biology, University of South Dakota, Vermillion, SD 57069, USA.
authors.forename: Megan L
authors.initials: ML
authors.lastname: Porter
authors.affiliation: School of Biological Sciences, University of Bristol, Tyndall Avenue, Bristol BS8 1TQ, UK.
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Radford
authors.affiliation: Department of Biological Sciences, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
authors.forename: Kathryn D
authors.initials: KD
authors.lastname: Feller
authors.affiliation: School of Biological Sciences, University of Bristol, Tyndall Avenue, Bristol BS8 1TQ, UK.
authors.forename: Shelby E
authors.initials: SE
authors.lastname: Temple
authors.affiliation: Department of Integrative Biology, University of California, Berkeley, CA 94720, USA.
authors.forename: Roy L
authors.initials: RL
authors.lastname: Caldwell
authors.affiliation: Queensland Brain Institute, The University of Queensland, St Lucia, QLD 4072, Australia.
authors.forename: N Justin
authors.initials: NJ
authors.lastname: Marshall
authors.affiliation: Department of Biological Sciences, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Cronin
authors.affiliation: School of Biological Sciences, University of Bristol, Tyndall Avenue, Bristol BS8 1TQ, UK nicholas.roberts@bristol.ac.uk.
authors.forename: Nicholas W
authors.initials: NW
authors.lastname: Roberts
mesh_terms: D000819:Animal Communication; D000818:Animals; D005075:Biological Evolution; D003445:Crustacea / Q000033:anatomy & histology* / Q000502:physiology*; D005121:Extremities / Q000033:anatomy & histology*; D008027:Light; D010802:Phylogeny; D059629:Signal-To-Noise Ratio; D013045:Species Specificity; D014796:Visual Perception / Q000502:physiology*
keywords: Mantis shrimp; Multi-modal signal; Polarization vision; Sensory bias; Signal evolution; Stomatopod