Shawshank LEDz Inc
My Account Contact Us
Home > About Scorpions
 

About Scorpions

Interesting Scorpion Facts

• California and Arizona have the largest assortment of scorpions, the count is approximately 60 species
• When exposed to ultraviolet light (black light) scorpions glow. This occurs because fluorescent chemicals are present in the cuticle
• One scorpion can have a brood of 2 to 100 babies
• Scorpions have a unique courting behavior that is specifically referred to as the "promenade à deux"
• Scorpions “sting” when threatened, and their venom is neurotoxic
• The Bark Scorpion, found primarily in Arizona, can scale walls and ceilings, then drop into beds, cribs, onto the kitchen table, etc.
• There are known to be more than 1500 scorpion species worldwide

Scorpions are venomous eight-legged carnivorous arthropods. They belong to the class Arachnida, and the order Scorpiones. There are approximately 2,000 species of scorpions spread across varies locations of the world. Scorpions are related to ticks, spiders, mites, and harvestmen along with many other Arachnida class members. Their extended bodies are segmented, with an erectile tail holding the telson (the sting) at the end. There are thought to be approximately 1,300 species of scorpions worldwide. According to fossil record, they are thought to have been living for nearly 430 million years.

For general identification, scorpions have four pairs of legs, one set of pincers, a long segmented tail and three to six pairs of eyes. They have a “crablike” appearance with their hard outer shell. There are many color variations ranging from a clearish tan to black.

ANATOMY

Scorpion's bodies have two parts, a cephalothorax and the opisthosoma. The cephalothorax (also referred to as the prosoma) is the head. The opisithosoma is the abdomen.

The cephalothorax is shielded by the carapace, which is a hard, bony, protective outer layer. The carapace (in most species) supports a set of eyes at the top center. Two to five pairs of eyes (depending on the species) are found at the front corners of the carapace. Chelicerae (the scorpion's mouthparts), and a pair of pedipalps (the claws used for prey capturing and mating) complete the anatomy of the head. The pedipalps are covered with trichobothria, sensory setae, that are able to sense airborne vibrations.

The opisithosoma, or abdomen is made up of the mesosoma, which is the main body, and the metasoma, which is the tail.

The mesosoma is divided by six different segments and is protected by a bony armor with chitinous plates, called tergites and sternites. The tergites are on the upper portion of the abdomen and the sternites are on the lower part of the abdomen. The sexual organs and genitals are located in the first segment. The second segment houses the pectines, which are feathery sensory organs that hang beneath the abdomen and trail on the ground. They are coated with chemosensors, which are used to detect minute chemical signals that are thought to alarm the scorpions of approaching prey. The pectines are also used in mating behaviors. The last four segments contain the respiratory structure. The respiratory structure, which is commonly referred to as "book lungs," are spiracles that open up into the scorpion's body. The outer surfaces of the legs and the body are covered with thick hairs that are very sensitive to direct touch. At the tips of the legs are small organs that detect vibrations from the ground.

The metasoma is also divided into six segments and curves upwards. The last segment has both the anus and the telson, which is the sting. The telson contains a bulbous vesicle holding a pair of venom glands and the hypodermic aculeus. The aculeus is a sharp, curved, venom injecting stinger. Scorpions, as a rare genetic abnormality, can have two tails.

Most of the species of scorpions reach a length of two to three inches at adulthood. The African Scorpion (Hadogenes troglodytes) is likely the longest scorpion in the world. It often grows to a length of more than 8 inches. The Giant Desert Hairy Scorpions, which are members of the genus Hadrurus, are likely the largest scorpions found in the U.S. They can reach a length of around 5 inches.

REPRODUCTION AND LIFE CYCLE

First, the male scorpion tracks down the female by following the pheromones that she emits. Once the male locates her, the courtship behavior begins with the use of the pedipalps. Using his pedipalps, he grabs the female by her pedipalps and will “dance” with the female. They move backward and sideways in a dance like motion that is specifically referred to as “promenade a deux.” During the dance, the male drags the female in the dance like motions until they reach a suitable, flat surface location. He wrestles her to accept the deposit of his spermatophore (this is a stalk like structure containing the sperm). The spermatophore is then drawn up into the females genitals. Her genital opening is towards the front of her abdomen, on the underside. In the courtship behaviors of particular species, the male will sting the female during the process to help subdue her. Sometimes, if the male remains near after mating, he will be killed and eaten. There are two known species that are able to reproduce without mating.

The gestational period ranges from several months to a year and a half, varying by species. The brood size ranges from one to over a hundred young scorpions which develop as embryos in the females ovariuterus. The average brood count is thought to be between eight and twenty five scorpions. After birth they crawl up onto the females back where they are carried for about the first two weeks of life. This behavior, classifying the scorpions as being viviparous, ends just after the first molt. While they are on their mothers back, they get water that is transferred through the mothers’ cuticle, and survive off of stored food supply. When the molt occurs, their first shell (which is soft) is shed. After this has occurred, they have developed enough strength and are large enough to care for themselves. Some species display more social development than others, and in these species, the first period of protection by the mother can be longer.

Scorpions reach maturity in two to six years, molting 5 to7 times during this period. With each molt, their out exoskeletal layer splits just below the carapace. The scorpion then crawls out to grow into the next one. The new shell is soft, making them vulnerable until it grows and hardens. The scorpion stretches frequently while the shell is soft, ensuring that it will be large enough when it hardens. Sclerotization is the term used for this hardening process. During the sclerotization process, while the shell is soft, the scorpions to not fluoresce. This will return gradually as the shell hardens.

The actual lifespan of most species is unknown. The lifespan range is thought to vary between four and twenty five years.

HABITAT

In the United State, the highest concentration of scorpions are in the semi-arid regions of Arizona, adjacent parts of California, and some areas of New Mexico and Texas. While there are about 90 species in the US, all but four are west of the Mississippi River.
The preferred temperature range for scorpions is between 68°F and 99°F. They are capable of surviving in a much wider temperature range though. They can hibernate through winter, and aestivate through a hot desert summer. A few species are able to survive winter temperatures dipping as low as -25°C. These few species are the Scorpiops of the high Asian mountains, the Bothriurids of Patagonia, and the Euscorpios from middle Europe.

Scorpion are most prevalent in warm habitats, but have adapted too many different environments including the high elevations of the Andes Mountains, the Asian Himalayas and the Alps. In snowy areas, scorpions hibernate during cold periods. In areas of drought they can aestivate, which means they get through the drought by being in a dormant or inactive state. Scorpions can survive in areas such as plains, savannahs, caves, forests (deciduous and mountainous pine).

BEHAVIORS

Scorpions are nocturnal and fossorial beings. They actively hunt and feed at night, and take shelter in cool, dry places by day. They hide under rocks, in holes, in logs, crevices and burrows. Fossorials are classified as having limbs adapted for digging. Some species dig, creating their own burrows. Scorpions avoid light to limit their visibility by predators. Some of their predators include mice, possums, rats, centipedes, tarantulas, lizards, bats and birds.

Scorpions prey on all types of insects, including spiders, centipedes and other scorpions. Larger scorpions can also feed on small vertebrates, including lizards, snakes and mice. They sometimes paralyze their prey with venom prior to capturing the prey with their pedipalps. Scorpions have small claw like structures protruding from their mouths that are called chelicerae. The chelicerae are very sharp, and are used to dissect prey into small pieces. Scorpions are only able to digest liquid forms of food, so solid remains are disposed of by the scorpion. Some species of scorpions can spray an acid onto their prey to dissolve parts into a more liquid form.

VENOM

All scorpion species carry venom. They use the venom to subdue prey for capture, to defend themselves when threatened, and in the mating process. All species, but one, carry venom that is considered to be neurotoxic. The only species that differs is the Hemiscorpius lepturus, whose venom is cytoxic. The neurotoxic venom is made up of a wide range of small proteins, salts, peptides and molecules that effect neurons responsible for action potentials. This venom affects the victims’ neurotransmission. Some scorpions release a pre-venom that is less toxic prior to releasing the more potent venom if threat continues. The pre-venom is translucent, is weaker, and is intended to stun. The next release is a more toxic venom, opaque in color, and is designed to kill. Scorpions have muscular control of the amount of venom released, according to the size of their target. When a scorpion has depleted their venom supply, it can take days to replenish.
While the venomous sting of most species is not deadly, it can be. Human death as a result of a scorpion sting is more typically in the young, elderly and ill. It is possible to be allergic to the scorpions venom, which can cause anaphylactic shock, and even death. Most often, the sting is not deadly. Scorpion stings cause swelling, pain, warmth, tenderness and numbness. The numbness at the location of the sting can last for days. A more serious sting can also cause cardiovascular issues such as tachycardia, bradycardia and on rare occasion, even pulmonary edema.

North American scorpion stings are typically mild, but that is not necessarily the case with the Arizona Bark Scorpion. The Arizona bark scorpion has a more toxic sting. Children are more likely to have more severe reactions from the Arizona Bark Scorpion. Some of the symptoms can include increased saliva, restlessness, sweating, muscle twitching/jerking, and abnormal head, eye and neck movements. If you suspect that you have been stung by a Bark Scorpion, you should seek medical attention immediately.

Medical treatment is not always necessary, but is a safe choice. Less serious stings are often treated with ice and ointments, but some require anti-venom or intravenous medications. If you have been stung, you can contact poison control for information at 1-800-222-1222.