Your Shades of Blue Look Splendens
The male peacock spider is quite literally the itsy-bitsy little spider, only about four millimeters long. No matter their size, these guys have bright colored patterns covering their bodies, used for visual communication and gaining the attention of females.
Maratus splendens uses two different mechanisms to create the hues that appear on the spider’s modified hairs. One way uses pigments, just as humans and flowers do, in order to produce the reds, whites and creams on the spider. The blue appearing on this arachnid is produced by very tiny nanostructures that reflect light of a particular wavelength. These structures are embedded in flat, convex scales which amplify the light reflections. Structural color has been well documented in many species, though it is still much less common than pigment coloration.
“We’ve known for some time that butterflies and moths are doing all sorts of really clever things with manipulating the behavior of light with their scales. What we’re discovering with this study and others is that spiders, which are obviously a very different group of animals, are also playing with light,” stated Nathan Morehouse from the University of Pittsburgh.
Unlike pigments that fade over a period of time, undamaged structural color will not. This is why insects and birds held in museums keep their sheen after so many years. It seems that the majority of creatures produce their blue shades by using structural color rather than with pigments. This does not apply to plants as they easily make blue pigments.
Lead author Doekele Stavenga, professor at the University of Groningen, explains, "The special photonic invention of the Maratus splendens scales is the insertion of two layers of extremely fine threads or filaments that subtly tune the refractive index profile of the multilayers, thus creating the distinct blue color.” Stavenga and a team of researchers used a range of techniques including a scanning electron microscope (SEM) to study the spider’s colors in depth. They discovered that these blue colors are not only structural, but some other type that has never been described before.
So, can female Maratus even see the brilliant colors their suitors flash for their appreciation-or lack of? “We have very good evidence that these animals can see these colors. It would be no surprise for them to see blue but the twist is that they can see, well, we think they can see, the red,” Morehouse says. This would make this species a bit odd among arachnids since many are not known for having good color vision. If the females can interpret the differences between shades of color, then they ought to be able to pick out superior male designs as well.
To think, all of that happening within the teeny tiny ecosystems of these wee spiders. Life really is complex, no matter how small.
--Mi
Image Credit – http://bit.ly/2biOAW0 http://bit.ly/2btGiI8
Source – http://bit.ly/2bihnas