OphidianDelight
Arachnoknight
- Joined
- May 19, 2011
- Messages
- 190
I was bored at 6am on Saturday morning and decided to find out exactly how and why scorpions fluoresce, not to mention why they don't after molting or as babies. I found a study done by Frost, Butler, Dell and Fet done in 2001 that seems to have hit the nail on the head. Here is the link to the complete article-- http://science.marshall.edu/fet/Euscorpius/fetpubl/Coumarin.pdf
How Scorpions Fluoresce: A Lab Study Summary
4-methyl-7-hydroxycoumarin is the chemical compound that makes scorpions fluoresce under black light. The fluorescent compound is found in the hyaline exocuticle, the top-most layer of exoskeleton; this layer is less than four micrometers thick and contains a dubious amount of chitin. This compound can be extracted; keeping the expired specimen's body in a 70/30 ethanol/water for more than a year will cause the fluid to fluoresce as well.
4-methyl-7-hydroxycoumarin is synthesized as an antispasmodic and a choleretic. Coumarin compounds are predominately found in plants. A scorpion does not fluoresce at first instar and for a short period after each subsequent molt; the fluorescence is assumed to be a result of aromatic molecules in the outer-most layer cross-linking with cuticular proteins in a process called cuticular sclerotization.
It is hypothesized that this adaptation developed during the scorpion's evolution from an aquatic lifeform into a terrestrial; the compound supposedly reduced harm and damage from UV radiation during a fragile step in the scorpion's evolution. A hyaline exocuticle can be found tracing back to the first scorpion fossils, making it possible for one to draw the conclusion that scorpion fluorescence may be a vestigial benefit since modern specimens are highly photophobic and maintain a nocturnal lifestyle.
How Scorpions Fluoresce: A Lab Study Summary
4-methyl-7-hydroxycoumarin is the chemical compound that makes scorpions fluoresce under black light. The fluorescent compound is found in the hyaline exocuticle, the top-most layer of exoskeleton; this layer is less than four micrometers thick and contains a dubious amount of chitin. This compound can be extracted; keeping the expired specimen's body in a 70/30 ethanol/water for more than a year will cause the fluid to fluoresce as well.
4-methyl-7-hydroxycoumarin is synthesized as an antispasmodic and a choleretic. Coumarin compounds are predominately found in plants. A scorpion does not fluoresce at first instar and for a short period after each subsequent molt; the fluorescence is assumed to be a result of aromatic molecules in the outer-most layer cross-linking with cuticular proteins in a process called cuticular sclerotization.
It is hypothesized that this adaptation developed during the scorpion's evolution from an aquatic lifeform into a terrestrial; the compound supposedly reduced harm and damage from UV radiation during a fragile step in the scorpion's evolution. A hyaline exocuticle can be found tracing back to the first scorpion fossils, making it possible for one to draw the conclusion that scorpion fluorescence may be a vestigial benefit since modern specimens are highly photophobic and maintain a nocturnal lifestyle.