title: Color Richness in Cephalopod Chromatophores Originating from High Refractive Index Biomolecules.
abstract: Cephalopods are arguably one of the most photonically sophisticated marine animals, as they can rapidly adapt their dermal color and texture to their surroundings using both structural and pigmentary coloration. Their chromatophore organs facilitate this process, but the molecular mechanism potentiating color change is not well understood. We hypothesize that the pigments, which are localized within nanostructured granules in the chromatophore, enhance the scattering of light within the dermal tissue. To test this, we extracted the phenoxazone-based pigments from the chromatophore and extrapolated their complex refractive index (RI) from experimentally determined real and approximated imaginary portions of the RI. Mie theory was used to calculate the absorbance and scattering cross sections (cm2/particle) across a broad diameter range at λ = 589 nm. We observed that the pigments were more likely to scatter attenuated light than absorb it and that these characteristics may contribute to the color richness of cephalopods.
authors.affiliation: Department of Chemistry, University of New Hampshire , Durham, New Hampshire 03824, United States.
authors.forename: Sean R
authors.initials: SR
authors.lastname: Dinneen
authors.affiliation: Nanomaterials Team, US Army Natick Soldier Research, Development, and Engineering Center , Natick, Massachusetts 01760, United States.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Osgood
authors.affiliation: Department of Chemistry, University of New Hampshire , Durham, New Hampshire 03824, United States.
authors.forename: Margaret E
authors.initials: ME
authors.lastname: Greenslade
authors.affiliation: Department of Chemistry and Chemical Biology, Northeastern University , Boston, Massachusetts 02115, United States.
authors.forename: Leila F
authors.identifier: http://orcid.org/0000-0003-3226-2470
authors.initials: LF
authors.lastname: Deravi
mesh_terms: D000818:Animals; D049830:Cephalopoda / Q000737:chemistry*; D002856:Chromatophores / Q000378:metabolism*; D003116:Color; D003118:Color Perception; D008027:Light; D010078:Oxazines / Q000737:chemistry; D012031:Refractometry; D012542:Scattering, Radiation; D012880:Skin Pigmentation
chemical_list: D010078:Oxazines; C020456:phenoxazinone