title: Under- and over-water halves of Gyrinidae beetle eyes harbor different corneal nanocoatings providing adaptation to the water and air environments.
abstract: Whirligig beetles (Gyrinidae) inhabit water surfaces and possess unique eyes which are split into the overwater and underwater parts. In this study we analyze the micro- and nanostructure of the split eyes of two Gyrinidae beetles genera, Gyrinus and Orectochilus. We find that corneae of the overwater ommatidia are covered with maze-like nanostructures, while the corneal surface of the underwater eyes is smooth. We further show that the overwater nanostructures possess no anti-wetting, but the anti-reflective properties with the spectral preference in the range of 450-600 nm. These findings illustrate the adaptation of the corneal nanocoating of the two halves of an insect's eye to two different environments. The novel natural anti-reflective nanocoating we describe may find future technological applications.
authors.affiliation: Institute of Protein Research, Russian Academy of Sciences, Pushchino, Russian Federation.
authors.forename: Artem
authors.initials: A
authors.lastname: Blagodatski
authors.affiliation: Institute of Protein Research, Russian Academy of Sciences, Pushchino, Russian Federation.
authors.forename: Michail
authors.initials: M
authors.lastname: Kryuchkov
authors.affiliation: Institute of Mathematical Problems of Biology, Russian Academy of Sciences, Pushchino, Russian Federation.
authors.forename: Anton
authors.initials: A
authors.lastname: Sergeev
authors.affiliation: Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russian Federation.
authors.forename: Andrey A
authors.initials: AA
authors.lastname: Klimov
authors.affiliation: Faculty of Physics, Lomonosov Moscow State University, Moscow, Russian Federation.
authors.forename: Maxim R
authors.initials: MR
authors.lastname: Shcherbakov
authors.affiliation: Institute of Protein Research, Russian Academy of Sciences, Pushchino, Russian Federation.
authors.forename: Gennadiy A
authors.initials: GA
authors.lastname: Enin
authors.affiliation: 1] Institute of Protein Research, Russian Academy of Sciences, Pushchino, Russian Federation [2] Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland.
authors.forename: Vladimir L
authors.initials: VL
authors.lastname: Katanaev
mesh_terms: D000222:Adaptation, Physiological; D000388:Air; D000818:Animals; D001517:Coleoptera; D003315:Cornea / Q000502:physiology*; D018625:Microscopy, Atomic Force; D036103:Nanotechnology; D013059:Spectrum Analysis, Raman; D013499:Surface Properties; D014867:Water / Q000737:chemistry*; D017155:Wettability
chemical_list: D014867:Water
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