Thursday, May 12, 2016

Spinning Tales About Scorpions



Scorpions are arthropods—classified as arachnids.  They prevail worldwide except Antarctica.   Fossils, some revealed in coal and amber, suggest they existed around 430 million years.   Special features are molting exoskeletons, 8 legs, crab-like claws, and forward curled tails tipped with stingers which release neurotoxic venom.  Vibrations and sense of smell compensate for poor eyesight—even with up to 12 eyes.  Coloration provides camouflage and depends on where they live; it may include red, yellow, green, tan, brown, or black.  Some are white—as babies or after molting.  Adult length is less than l inch to over 8 inches.  Longevity usually spans 3-5 years.
During courtship, mates grasp pincers and dance.  Females are commonly larger.  Following live births, scorplings cling to mothers’ backs until molting.  Broods range from 2-100.  Females may eat their young to survive.
Loose soil and warm, dry climates are preferable, but habitats are adaptable:  deserts (common), rain forests, even the Himalayas.  In snowy areas, hibernation occurs.  Incredibly, researchers froze scorpions overnight, and, when thawed out the next day, they walked away. 
Extremely sensitive to light, they might take shelter during the day in sand, rocks, burrows, trees, or potted plants.  Thus, they avoid predators like birds and also retain crucial body moisture.  They may invade homes, especially under construction, since they squeeze through cracks as thin as credit cards.  They glow under ultraviolet light—beneficial to exterminators.
These opportunistic nocturnal predators relish insects.  Prey is crushed with pincers or paralyzed or killed with venom.  Digestive fluids liquefy prey before ingestion.  When food is scarce, scorpions can endure 6 to 12 months of starvation. 
Florida scorpon - photo Wildflorida.com


Among species, venom is unique.  Smaller species are often more toxic; larger species sometimes need only intimidate.  Newborns should not be underestimated.  To conserve venom, dosage is regulated according to victims; dry stings occur.  
Approximately 90 species inhabit the United States, chiefly in the Southwest.  Most dangerous in North America are the Arizona bark scorpions.  They are robust and can survive nuclear ground zero.  Though scorpions are customarily solitary, this species lives in packs.   Probably, the world’s deadliest are the fattail and the deathstalker scorpions of Africa and the Middle East and the Indian red scorpions.  Fortunately, Florida’s 3 species are considered minor pests.
Less than 5% of humans (particularly the young, elderly, and allergic) need treatment for stings delivered by threatened scorpions.  Stings are generally just painful—comparable to a wasp sting.  Fatalities are rare in this country. 
Scorpion venom is used in insecticides and vaccines.  In Pakistan, the venom of large black scorpions is worth thousands of dollars for medicinal research.  Ancient Chinese physicians used scorpion venom for drooping eyelids.  Helpful scorpions!

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