title: A dynamic broadband reflector built from microscopic silica spheres in the 'disco' clam Ctenoides ales.
abstract: The 'disco' or 'electric' clam Ctenoides ales (Limidae) is the only species of bivalve known to have a behaviourally mediated photic display. This display is so vivid that it has been repeatedly confused for bioluminescence, but it is actually the result of scattered light. The flashing occurs on the mantle lip, where electron microscopy revealed two distinct tissue sides: one highly scattering side that contains dense aggregations of spheres composed of silica, and one highly absorbing side that does not. High-speed video confirmed that the two sides act in concert to alternate between vivid broadband reflectance and strong absorption in the blue region of the spectrum. Optical modelling suggests that the diameter of the spheres is nearly optimal for scattering visible light, especially at shorter wavelengths which predominate in their environment. This simple mechanism produces a striking optical effect that may function as a signal.
authors: Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720, USA lindseydougherty@berkeley.edu.
authors: Lindsey F
authors: LF
authors: Dougherty
authors: Department of Biology, Duke University, Durham, NC 27708, USA.
authors: Sönke
authors: S
authors: Johnsen
authors: Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720, USA.
authors: Roy L
authors: RL
authors: Caldwell
authors: Queensland Brain Institute, University of Queensland, Brisbane, Queensland 4072, Australia.
authors: N Justin
authors: NJ
authors: Marshall
mesh_terms: D000465:Algorithms; D000818:Animals; D049872:Bivalvia / Q000502:physiology*; D008027:Light; D049449:Luminescence; D046529:Microscopy, Electron, Transmission; D055095:Optics and Photonics; D056951:Photoelectron Spectroscopy; D012542:Scattering, Radiation; D012822:Silicon Dioxide / Q000737:chemistry*; D014741:Video Recording
chemical_list: D012822:Silicon Dioxide
keywords: Ctenoides; bivalve; optics; reflection; scattering; silica