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tags:biologyanimalstransparency
rel: Butterfly Wings Disruptive Eye Mask
NOTE
Cataloguing times and reasons for animals turning “invisible” through evolved transparency.
Grasswing Butterfly
Firstly, their wings lack the densely packed pigmented scales that are usual in butterflies. Instead, the see-through membrane of their wings is overlaid with sparse, spindly scales leaving gaps for light to pass through.
Glass Frogs
Fascinatingly, it has recently been discovered that this clever camouflage goes even further, with glass frogs possessing the ability to strategically remove red blood cells from circulation when needed, and store them in their liver for a while. This makes them look even clearer and more see-through, as red blood cells are what give blood its vibrant colour.
Research
Applying tartrazine to induce transparency in rats
Achieving optical transparency in live animals with absorbing molecules (2024)
Optical imaging of biological tissues is hindered by the scattering and, to a lesser extent, absorption of light that limits the penetration depth. The authors show that the addition of common dye molecules that absorb in the near ultraviolet and blue regions improve optical transparency in nearby longer wavelengths. In essence, by causing sharp absorption in the blue region, the refractive index in the red part of the spectrum is increased without increasing absorption. The addition of tartrazine was able to make the skin of a live rodent temporarily transparent.