Critter Guide: Scorpion

Scorpion

 

critter_scorpionThere are many scorpions in the Grand Canyon state. Venom from only one of the 30 species of Arizona scorpions, the bark scorpion,  is considered life-threatening. The largest type of scorpion found in the Foothills is the desert hairy scorpion which can reach a length of 95 mm.

They go way back

Scorpions belong to a phylum of joint-legged animals with external skeletons called arthropods. This is the largest group in the animal kingdom with well over a million and a half species.  The oldest known arthropods are the extinct trilobites, marine animals that flourished 550 to 450 million years ago.  One type arthropod, arachnids, include spiders, mites, ticks and scorpions.   All of which produce venom. Most arachnids are meat eating and partial digestion takes place outside the body when digestive enzymes are poured into prey tissue as the prey is held the animal’s pincers. Prey usually consist of other arthropods. Scorpions are the oldest known arthropods that live on land.  Fossil scorpions, very similar to present-day species, are in found in beds of rock over 400 million years old.

Scorpions  have six to 12 eyes depending on the species. Their breathing spores are on their abdomens.

Waiting in ambush

Scorpions spend the daylight hours under cover or in burrows. They emerge at night within their  defended territories and wait to ambush prey consisting of insects, other arthropods, and occasionally small reptiles and young rodents.  They catch the victim with their pincers and kill or paralyze it with a sting. Scorpions are active only when nighttime low temperatures exceed about 77 degrees. They are inactive and rarely seen during winter months.

On their mother’s back

Young scorpions develop within the body of the female and are born alive. After their birth, the mother carries them about on her back until they have undergone at least one molt (shedding of skin).  Eventually they get off their mother’s back to began an independent existence. Scorpions may live for several years.  Scorpions in Arizona are preyed upon by rodents, birds and reptiles.

Not aggressive

Scorpions are not aggressive toward nonprey, and only sting when handled or otherwise molested.  Children and older people, especially those with respiratory problems and heart disease, are particularly vulnerable to the venom.

The author’s scorpion sting

Scorpions have a terrifying and deadly reputation enhanced considerably by Hollywood. However, a scorpion’s sting rarely lives up to its reputation.  This writer was stung on the toe by a scorpion after stepping on it with a bare foot while walking in the back yard at night (In other words, I asked for it!).  The sting  was akin to several simultaneous wasp stings.  I laughed when I saw it was  such a small critter had caused me to jump so high and so many times.  I was relieved it was not a rattlesnake that had delivered my discomfort.   After awhile there was a temporary numbness in my leg, then my lips. I took  some aspirin, rested and was fine. My toe was numb for two days.