Glow-in-the-Dark Scorpions Exposed by UV Light

Image: Matt Reinbold, Flickr

Research reveals that scorpions glow blue-green under black light — and while no one knows exactly why, scientists have put forward some theories.

Scorpions are predatory arachnids native to nearly every continent on earth. Their environmental adaptability makes them formidable opponents, remarkable for their ability to hide camouflaged from predators during the day and hunt in the darkness of the night.

Studies have shown that scorpions fluoresce bright blue when illuminated by black lights, leading scientists to analyze a number of curious theories.

As nocturnal creatures, scorpions loathe the effects of sunlight and UV light in general, including the small amounts produced by bright moonlight. A report in the Journal of Arachnology concludes that scorpions are less active during times of greater UV exposure. This theory is solidified by their extremely sensitive eyesight.


Douglas Gaffin from the University of Oklahoma explains that capacity for the conversion of UV light to the more desirable blue-green glow wavelengths allows them to find better hiding places. In essence, a scorpion’s limited vision is increased to span its entire body by being encapsulated in the color of light it sees best. This gives them the ability to sense light — and “see” — with their entire bodies.

The blue-green glow is created by a beta-carboline component found in the hyaline layer of the scorpion’s cuticle and occurs as a by-product of the hardening of the exoskeleton between molting periods.

While the capacity for scorpions to glow in the dark is beneficial to its own species, it also benefits those trying to avoid contact with these pinching, stinging, armored creatures. Just don’t leave home without your UV light!

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