These spiders are very unique. They may look like some piece of delicate jewelry, but in fact they’re a rare species of spider. They’re called mirror or sequined spiders and belong to the hwaitesia genus. This genus features spiders with reflective silvery patches on their abdomen.
The scales look like solid pieces of mirror glued to the spider’s back, but they can actually change size depending on how threatened the spider feels. The reflective scales are composed of reflective guanine, which these and other spiders use to give themselves color. Not much information is available about these wonderful spiders, but the dazzling specimens in these photos were photographed primarily in Australia and Singapore.
This unusual and beautiful “sequined” spider reflects light off the many mirrors encompassing its abdomen in order to confuse predators. Thwaitesia spiders are members of the Theridiidae family, which includes tangle-web spiders, cobweb spiders and comb-footed spiders. This particular creature is unique in that its body is covered in what looks like a canvas of mirrors.
Researchers have determined that the spiders use these reflective areas to scatter light in order to evade predation, making it difficult for other animals to see them. These glimmering splotches are most likely crystalline deposits comprised of guanine. Spiders are generally renowned for their camouflage capabilities, highlighted by the diversity of species that are capable of changing color. Some are even able to contract their guanine sequin spots.
Biologist and author of the Find-a-Spider Guide for the Spiders of Southern Queensland Ron Atkinson explained to Science Friday that these unique “mirror” cells are located right under their transparent skin on the spider’s abdomen.
The purpose of the guanine spots is possibly to resemble water droplets that persist in the green vegetation of their native habitats. There are many species of Thwaitesia spiders but many of them may remain unknown to science. They are relatively small animals, measuring 2-5 mm in length, and are completely harmless to humans.
“There are several Thwaitesia in China and Vietnam, as well as one each in Myanmar and New Guinea,” states Atkinson. “I am confident that more Thwaitesia species will be found and described in Southeast Asia in the near future.”