Temporal range: Late Ordovician - Recent, 468 - 0 Mya
|Hottentotta tamulus from Maharashtra, India|
Scorpions are eight legged venomous arachnids. They have a long body with an extended tail with a sting. The average adult scorpion is about 3 inches in length. The longest scorpion is the African scorpion, which can be 9 inches long. There are about 1,750 species of scorpions worldwide.
The evolutionary history of scorpions goes back to the Ordovician, about 470 million years ago. They have adapted to a wide range of environments, and live on all continents except Antarctica. They only lived in Antarctica until about 50 Million years ago, when it became cold there. There are 13 living families. Only about 25 species have venom which can kill a human being.
Anatomy[change | change source]
Their body is in three parts. The front section is the cephalothorax; the abdomen is called the mesosoma, and the tail is the metasoma. The body is covered by an exoskeleton which gives them good protection.
Survival in the desert[change | change source]
Scorpions have many ways to survive in the desert. They can slow down their metabolism. This allows them to survive on as little as one insect per year. This ability also allows them to shelter from the sun and heat for extended periods of time, using only little amounts of oxygen. Many people also believe that their claws, or pincers, were once front legs that have turned into what they now are by going through evolution. Nevertheless, the scorpions' claws play a crucial part in their hunting and mating rituals. Scorpions also possess a special, feather-like pair of organs, called pectines that they use to sense even the smallest of movements around them. This allows them to effectively track down and hunt their prey, either above or below the surface. This also warns them of possible dangers, such as other bigger hunters. The scorpion’s most feared and recognized feature is its sting. The sting contains a neurotoxin, which the scorpion uses to paralyze the victim, so it would be easier to kill and eat. They also stay hidden under rocks and that makes their body temperature cool.
Breeding cycle[change | change source]
The mating ritual of scorpions begins when the male and female connect claws. After this they verify that the other scorpion is of the same species, and is the opposite gender. After this, the male leads the female around until it finds a suitable spot to deposit its spermatophore. Once the male has found a suitable spot, he guides the female over it, where it enters her and fertilizes her. The mating ritual can take anywhere between 1 and 26 hours, depending on the male’s ability to find a suitable spot. Only a scorpion that has reached maturity may go through the mating ritual. A scorpion reaches maturity after it has gone through 5 to 7 moults.
Related pages[change | change source]
References[change | change source]
|Wikimedia Commons has media related to: Scorpiones|
|Wikispecies has information on: Scorpiones.|
- Ruppert, Edward E. 2004. et al 2004. Invertebrate zoology. Brooks/Cole. ISBN 978-81-315-0104-7
- František Kovařík (2009). "Illustrated catalog of scorpions, Part I" (PDF). http://kovarex.com/scorpio/pdf/scorpions-Kovarik-2009.pdf. Retrieved January 22, 2011.
- ThinkQuest: Poisonous Animals: Scorpions. 2000. 
- Polis, Gary A. 1990. The biology of scorpions. Stanford University Press. ISBN 978-0-8047-1249-1 
- Scorpion facts and information.