BioTechniques
Using Internet databases, Hsiung’s team surveyed the colors of tarantulas from 53 genera and identified 40 genera with blue coloration. They obtained specimens from eight different species to analyze by microscopy and optical modeling.
“We saw different types of nanostructures, such as multilayer structures and quasi-ordered sponge-like structures. … These different types of nanostructures are all capable of producing infinite variations of colors from blue to red,” said Hsiung. “However, they all evolved to produce this specific blue using very different mechanisms, which is rare.”
Hsiung’s team next reconstructed evolutionary trees for the blue species, illustrating that the similar blue coloration had independently evolved at least eight times across multiple species through at least three divergent color-producing nanostructures.
Unlike the structural colors of birds or butterflies, tarantulas produce non-iridescent colors that maintain their hue when viewed from any angle. Understanding how tarantula nanostructures produce color could replace energy-intensive LCD technology, since active backlight illumination would not be required.
“We think the tarantula could be key to addressing these problems, and we are using different nanofabrication technologies to replicate the tarantula nanostructures and produce non-iridescent structural color,” said Hsiung.
Reference
Hsiung BK, Deheyn DD, Shawkey MD, Blackledge TA. Blue reflectance in tarantulas is evolutionarily conserved despite nanostructural diversity. Sci Adv. 2015 Nov 27;1(10):e1500709.