Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Scorpiones
Family: Buthidae
Genus: Leiurus
Species: L. quinquestriatus
Background Information on Scorpions
The fossil evidence indicates that the earliest scorpions (400-425 million years ago during the middle Siluran) were aquatic with gills and legs that looked like those species living today(Rubio 13). It is estimated that around 325-350 million years ago scorpions evolved in order to move to land.When scorpion first move to land they were mainly small specimens, there was one large species called Praearcturus gigas, which was about three feet long in length. Scorpions are carnivorous and usually consume invertebrates, but can eat small vertebrates as well. There are currently about 1,500 species of scorpions and subspecies of extant scorpions into sixteen families (Rubio 13).
Description
Leiurus quinqestriatus, which means five-striped smooth-tail, is most commonly know as the Deathstalker, but it also called Omdurman scorpion or Israeli desert scorpion. The Deathstalker is straw yellow in color, and can grow 3.5 to 4.5 inches (9 to 11.5 cm) in length (“Deathstalker Scorpion.”). The scorpion has narrow pedipals, sleek body, and a long thin tail, which usually has a dark segment by the stringer (aculeus). The stringer and pincer tips are usually a darker color than the rest of the body usually almost black in color. Females are typically larger in size compared to males.
Habitat and Range
The Deathstalker is native to the arid rocky desert regions of North Africa and the Middle East. Deathstalker are found in northeastern Africa as far west as Algeria and Niger, as far south as Sudan, and as far west as Somalia. Members of the subspeices L. quinquestriatus hebraeus are found throughout the Middle East as far north as Turkey, east to Iran, and south of Oman and Yemen (Ceceli and Horsfield). They are usually found in burrows in under rocks or abandoned burrows of other animals.
Anatomy
Scorpion are ectothermic and have to seek heat for their surroundings. Scorpions are covered by exoskeleton that helps to support and protect its organs from external forces. The body of scorpion are divided into two sections, the prosoma (cephalothorax) and the opisthosoma (abdomen) (Rubio 15). The Chelicerae allows for the scorpion to tear and grind food into smaller pieces before going into the mouth to by digested. They also have a pair of median eyes, these eyes are are a primate way to perceive depth and spatial awareness. while lateral eyes seem to be more of a biological clock in a sense. The metasoma is looks like what you would call a tail portion of the body that is made up of five segment and at the end it has the telson, which has a portion that contains the stringer that is called the aculeus (Rubio 17). The metasoma contains portions of the intestines and hindgut. It can be used for stinging (for prey and defense), digging, scraping, balance, and climbing (Rubio 18). The Telson also contains the venom glands that produces a toxin. The anal opening is located between the last segment of the metasoma and the telson in the soft tissue. Scorpions have four pairs of jointed legs, which allow them to get around, as well as dig. The scorpion also has a pair of pedipaps , which has the pincers at the end. The main use of pedipaps are for grabbing, holding, and crushing prey, they can also be used for protection,digging, and sensing the surroundings. Scorpions have pectines that allow them to detect vibrations as well as pick up pheromones during mating season.They have setae that are hairlike structures that allow them physical, thermal, chemical, and humidity information from their surroundings.
Toxin
When someone gets stung by a Deathstalker the initial symptoms usually associated with most envenomation (pain, muscle contractions, excessive salivation, respiratory irregularity, twitching and convulsions, an unstable pulse rate, and erratic body temperature), the seriousness of a sting is often initially underestimated (Rubio 34). If the sting has been not treated this can lead to being fatal by heart failure, this happens by the patient going into shock, develop progressive respiratory paralysis, have pulmonary edema, and heart inflammation; with the eventual result likely being heart failure (Rubio 34). Their Venom is most toxic of any known scorpion, they cause 85 percent of all strings report and 90 percent of the deaths caused by scorpion stings (Rubio 33). Chlorotoxin is a peptide in the venom, which is being studied.
[Chlorotoxin has several properties that make it a good starting point for drug design: (i) it is able to bind preferentially to tumor cells, making the design of therapeutics using chlorotoxin as a scaffold to treat glioma and other types of cancer of neuroectodermal origin such as melanoma, neuroblastoma and medullobastoma possible; (ii) to date, no obvious toxicities nor immunogenic responses after being administered to humans have been reported; and (iii) chlorotoxin is reportedly able to enter the brain and be internalized by cells, suggesting that it could be used to deliver drugs to the brain and/or intracellular targets] (Ojeda, Wang, and Crail).
Chlorotoxin has some possibility in the future to help with curing diseases but there needs to be more studies to be done to tell if they will actually be beneficial.
Reproduction
Citations
Ceceli, Ahmet, and John Horsfield. "Leiurus quinquestriatus." Animal Diversity Web, 2012. http://animaldiversity.org/accounts/Leiurus_quinquestriatus/. Accessed 30 November 2016.
“Deathstalker Scorpion.” NewYork-Presbyterian. 2013, http://www.nyp.org/deathstalkerscorpion/scorpion_facts.html. Accessed 30 November 2016.
O’Brien, Kevin, and Kayla Theis. The Five-striped Smooth-tail. The University of Wisoconsin-La Crosse, 2008. https://bioweb.uwlax.edu/bio203/s2014/obrien_kev2/index.htm. Accessed 1 December 2016.
Ojeda, Paola, Conan Wang, and David Craik, “Chlorotoxin: Structure, activity, and potential uses in cancer therapy.” Vol. 106, pg. 25-36. Biopolymers, 1 January 2016. https://www-scopus-com.proxy.lib.iastate.edu/record/display.uri?eid=2-s2.0-84961325346&origin=resultslist&sort=plf-f&src=s&st1=Leiurus+quinquestriatus&st2=&sid=AA6EF2EFD96A9BFF769D4C62DBF02D96.wsnAw8kcdt7IPYLO0V48gA%3a10&sot=b&sdt=b&sl=38&s=TITLE-ABS-KEY%28Leiurus+quinquestriatus%29&relpos=2&citeCnt=2&searchTerm=. Accessed 1 December 2016.
Rubio, Manny. Scorpions. Barron’s Educational Series, 2000.
Image Citations
Grunthaner, Chris. Mating L.Q, 3 June 2009. America. Photobucket, http://s412.photobucket.com/user/jawlessemu/media/100_4589.jpg.html. Accessed 1 December 2016.
Jain, Khusboo. Fig. 18.107, 2016. Biology Discussion, http://www.biologydiscussion.com/invertebrate-zoology/phylum-arthropoda/scorpions-with-diagram-phylum-arthropoda/33501. Accessed 1 December 2016.
Mohney, Gillian. “FDA Approves Study of Scorpion-Derived ‘Tumor Paint’ for Brain Cancer Patients.” ABC News, 27 September 2014. http://abcnews.go.com/Health/fda-approves-study-scorpion-derived-tumor-paint-brain/story?id=25807433. Accessed 1 November 2016.
For reproduction to happen a female has to decide first if the male is good enough to mate with her. The male will grab her pedipalp chelae with his chelae fingers, then they start a dance that is called “promenade à deux”(O’Brien and Theis). If the female will decide after the dance if the male is a good fit, if so the male releases spermatophore. The male then positions the female over the spermatophore where the female takes up the sperm in to her ovariuterus to start reproduction of the embryos (O’Brien and Theis). After the mating is over they go their separate ways. The female's gestation period is between 122 to 227 days long (O’Brien and Theis) . A female can give birth from 12 to 85 offspring at a time with the average being 62 offspring(O’Brien and Theis).