Meeting Abstract

7.3  Monday, Jan. 4  Deep-sea silver: photonics and biochemistry of semi-coherent broadband reflectors on squid eyes SWEENEY, A.M.*; HOLT, A.L.; MASON, E.; MORSE, D.E.; University of California, Santa Barbara; University of California, Santa Barbara; University of California, Santa Barbara; University of California, Santa Barbara sweeney@lifesci.ucsb.edu

The eyes of most species of squid are covered in a silver layer which exhibits unusual cell biology, biochemistry, optical properties and visual ecology. This layer comprises a semi-coherent photonic reflector with unique angle- and polarization-independent reflectivity, making these tissues a model for a self-assembled wavelength-independent dielectric mirror. The optical material is composed of layered spindle-shaped cells providing high refractive index regions, and an expanded extracellular glycocalyx providing low refractive index regions. The optically homogeneous infill of the spindle-shaped cells is composed of a mixture of reflectin protein and a novel protein characterized by its high hydrophobic amino acid content. Interesting variations in the optical geometry and composition of this silver layer correspondingly change with the visual ecology of deep-sea squid species and have implications for underwater camouflage. The discovery of a second optically active protein in these reflective cells initiates our exploration of the organizing principles of self-assembly of soft photonic structures in organisms.