TRUE. Scorpions, dead or alive, and even fossilized scorpions have been found to fluoresce under UV light. An exception seems to be that newly molted scorpions do not fluoresce.

     A) It serves as a UV sensor

     B) It attracts insects that see in the UV spectrum, right to these ambush predators

     C) It serves as a warning to other scorpions and predators

No one knows exactly what the purpose this is for the scorpion but many theories abound. A, B, and C are the most popular reasons, yet still unproven. One thing is certain, it makes it incredibly easy for scientists to find these animals when studying the habits of these nocturnal creatures.

"The fluorescence is caused by an unidentified substance in a very thin layer in the cuticle of the scorpion called the hyaline layer. As the new cuticle hardens, the fluorescent quality increases. Newly molted scorpions do not fluoresce. This indicates that the fluorescent factor is either secreted by the scorpion shortly after molting or that the fluorescence is a by-product of the tanning process. Alcohol in which scorpions have been preserved may also fluoresce. The hyaline layer of the cuticle is very tough stuff. It is often found in scorpion fossils. Even after hundreds of millions of years, while all the other layers of the cuticle have been lost, this hyaline layer remains embedded in fossil rocks. And yes, it still fluoresces. Some have suggested that it serves as UV sensor (all scorpions are basically nocturnal and shun the light)." Paragraph Source: Dr. Scott A. Stockwell stockwell@wrbu.si.edu

[back to photo gallery]

Photo by Kenton Elliott