What causes the fluorescence in scorpions?
The fluorescence is caused by an unidentified substance in a very thin layer in the cuticle of the scorpion called the hyaline layer. Newly molted scorpions do not fluoresce. As the new cuticle hardens, the fluorescent quality increases. 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. Nobody knows the function of the hyaline cuticle or its strange fluorescence. Some have suggested that it serves as UV sensor (all scorpions are basically nocturnal and shun the light). This unusual feature can make scorpions easier to collect and observ
