Scorpion facts
Despite having six to twelve eyes - an obvious pair at the centre of the
carapace and two to five smaller eyes on each side - scorpions do not have good
eyesight. However, they can readily distinguish light from dark and appear to
have excellent low light sensitivity, which helps them to both avoid harsh
sunlight and to navigate by starlight or moonlight. They sense their way around
using sensory hairs and slit organs on the legs, pedipalps and body that pick up
vibrations and scents (mechanoreceptors and chemoreceptors). They also have
special organs on the underside of the body called pectines, which pick up
ground textures and scents.
Scorpions also fluoresce under ultraviolet light, which is a good way for
scientists to find them in the field. The fluorescence is thought to serve as an
ultraviolet sensitivity mechanism, perhaps allowing the scorpion to avoid
damaging light levels.
Males and females find each other by vibration, scent and touch. During mating,
the sensory pectines under the body are used to find a suitable place for the
male to deposit his sperm parcel - the spermatophore. The male and female then
perform a mating dance above the spermatophore, with the female being wrestled
into position over it in order to draw it up into her genital pore. The
fertilised eggs develop inside her body, and she then gives birth to live young.
She carries the pale young scorpions on her back for the first few days or
weeks, until they are strong enough to become independent. The young then
disperse to find food and shelter. Scorpions take a long time to reach maturity,
moulting frequently (up to five or six times over two to six years) in order to
grow, and may live for two to ten years. Some have been recorded as living up to
25 years.
Australian museums factsheet
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 observe. When
darkness falls, portable UV lights can be carried into the field where scorpions
live. Scorpions caught in the nearly invisible UV light glow an eerie greenish
color, making them easy to spot in the darkness.
Fluorescence in scoprioins
http://wrbu.si.edu/www/stockwell/faq/uv.html
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http://www.amonline.net.au/factsheets/scorpions.htm
Did you know?
1. Scorpions kill over a thousand people a year in Mexico.
2. There are over 1500 species of scorpion but only 25 can kill people.
3. Some scorpions can live a year without food or water.
http://www.elton.iinet.net.au/page61.html
more scorpion facts: http://wrbu.si.edu/www/stockwell/faq/size.html
Violent love: scorpion mating is dangerous for both parties. Most scorpions
are loners because of their cannibalistic tendencies. When two scorpions meet,
they usually fight until one is killed and eaten by the winner. After mating,
the smaller scorpion is often in danger of being eaten. As females are usually
bigger, it is the male which usually gets eaten.
The male and female find each other through pheromones, using their pectines.
The male usually makes the first move, although some females do so. He usually
has a complex courtship display to ensure the female knows he is one of her kind
and not lunch. Some males "judder" (rapid rocking, shaking movements) to
advertise his species (Vejovoides, Nebo). Some sting the female, possibly with
pheromones, sedatives or other species identificators. Others club the female
with their tails. Some males (Hadogenes) have ridiculously longer tails than
females, suggesting that the length is important more for mating than hunting
more scorpion facts on this excellent site: http://www.szgdocent.org/ff/f-scorp.htm