The mechanism of color change in the neon tetra fish: a light-induced tunable photonic crystal array.
The fresh water fish neon tetra has the ability to change the structural color of its lateral stripe in response to a change in the light conditions, from blue-green in the light-adapted state to indigo in the dark-adapted state. The colors are produced by constructive interference of light reflected from stacks of intracellular guanine crystals, forming tunable photonic crystal arrays. We have used micro X-ray diffraction to track in time distinct diffraction spots corresponding to individual crystal arrays within a single cell during the color change. We demonstrate that reversible variations in crystal tilt within individual arrays are responsible for the light-induced color variations. These results settle a long-standing debate between the two proposed models, the "Venetian blinds" model and the "accordion" model. The insight gained from this biogenic light-induced photonic tunable system may provide inspiration for the design of artificial optical tunable systems.
Department of Structural Biology, Weizmann Institute of Science, Rehovot, 76100 (Israel).
Dvir
D
Gur
Department of Structural Biology, Weizmann Institute of Science, Rehovot, 76100 (Israel).
Benjamin A
BA
Palmer
Department of Physics of Complex Systems Institution, Weizmann Institute of Science, Rehovot, 76100, (Israel).
Ben
B
Leshem
Department of Physics of Complex Systems Institution, Weizmann Institute of Science, Rehovot, 76100, (Israel).
Dan
D
Oron
Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam (Germany).
Peter
P
Fratzl
Department of Structural Biology, Weizmann Institute of Science, Rehovot, 76100 (Israel).
Steve
S
Weiner
Department of Structural Biology, Weizmann Institute of Science, Rehovot, 76100 (Israel). lia.addadi@weizmann.ac.il.
Lia
L
Addadi
D000818:Animals; D003116:Color; D005399:Fishes; D008027:Light; D008954:Models, Biological; D055095:Optics and Photonics; D017785:Photons; D014961:X-Ray Diffraction
X-ray diffraction; biomineralization; guanine crystals; structural colors; tunable photonic crystals