Deathstalker

Leiurus quinquestriatus
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Class:	Arachnida
Order:	Scorpiones
Family:	Buthidae
Genus:	Leiurus
Species:	L. quinquestriatus
Binomial name
Leiurus quinquestriatus
Subspecies
Leiurus quinquestriatus hebraeus Leiurus quinquestriatus quinquestriatus

The deathstalker (Leiurus quinquestriatus) is a species of scorpion, a member of the Buthidae family. It is also known as the Palestine yellow scorpion^[1][2][3][4] Omdurman scorpion, Naqab desert scorpion and many other colloquial names, which generally originate from the commercial captive trade of the animal. To eliminate confusion, especially important with potentially dangerous species, the scientific name is normally used to refer to them. The name Leiurus quinquestriatus roughly translates into English as "five-striped smooth-tail". Other species of the genus Leiurus are also often referred to as "deathstalkers".

Description

L. quinquestriatus is yellow, and 30–77 millimetres (1.2–3.0 in) long, with an average of 58 mm (2.3 in).^[5]

Geographic range

L. quinquestriatus can be found in desert and scrubland habitats ranging from North Africa through to the Middle East. Countries where it lives include Algeria, Bahrain, Chad, Egypt, Ethiopia, Palestine, Israel, Libya, Mali, Niger, Somalia, Sudan, Tunisia, Iraq, Jordan, Kuwait, Lebanon, Oman, Iran, Afghanistan, Pakistan, India, Qatar, Saudi Arabia, Syria, Turkey, Kazakhstan, Uzbekistan, United Arab Emirates, and Yemen.

Venom

A deathstalker eating a cricket in captivity

Neurotoxins in L. quinquestriatus venom include:

• Chlorotoxin
• Charybdotoxin
• Scyllatoxin
• Agitoxins types one, two and three

Hazards

The deathstalker is regarded as the most dangerous species of scorpion. Its venom is a powerful mixture of neurotoxins, with a low lethal dose.^[6] While a sting from this scorpion is extraordinarily painful, it normally would not kill a healthy adult human; young children, the elderly, or infirm (such as those with a heart condition and those who are allergic) are at much greater risk. Any envenomation runs the risk of anaphylaxis, a potentially life-threatening allergic reaction to the venom. A study from Israel shows a high rate of pancreatitis following envenomation.^[7] If a sting from Leiurus quinquestriatus does prove deadly, the cause of death is usually pulmonary edema.

Antivenom for the treatment of deathstalker envenomations is produced by pharmaceutical companies Twyford (German)^[8] and Sanofi Pasteur (French),^[9] and by the Antivenom and Vaccine Production Center in Riyadh.^[10] Envenomation by the deathstalker is considered a medical emergency even with antivenom treatment, as its venom is unusually resistant to treatment and typically requires large doses of antivenom.^[11]

In the United States and other countries outside of the typical range of the deathstalker, there is the additional complicating factor that none of the existing antivenoms are approved by the Food and Drug Administration (or equivalent agencies) and are only available as investigational drugs (INDs). The US Armed Forces maintain an investigational drug application^[12] for the AVPC-Riyadh antivenom in the event of envenomation of soldiers in the Gulf War theater of operations, and the Florida Antivenin Bank maintains an IND application for Sanofi Pasteur's Scorpifav antivenom.^[13]

Uses

Deathstalker, at negev desert, Israel.

A component of the deathstalker's venom, the peptide chlorotoxin, has shown potential for treating human brain tumors.^[14] There has also been some evidence to show that other components of the venom may aid in the regulation of insulin and could be used to treat diabetes .

In 2015 clinical trials were beginning of the use of chlorotoxin with a fluorescent molecule attached as brain tumour "paint" (BLZ-100), to mark cancerous cells in real time during an operation. This is important in brain cancer surgery, where it is vital both to remove as many cancerous cells as possible, but not to remove healthy tissue necessary for brain functioning. In preclinical animal trials the technique could highlight extremely small clusters of as few as 200 cancer cells, compared to the standard use of MRI, with a lower limit in excess of 500,000.^[15]

Legality

Possession of L.quinquestriatus may be illegal or regulated in countries with laws prohibiting the keeping of dangerous animals in general. Jurisdictions are increasingly explicitly including L.quinquestriatus in laws requiring permits to keep animals which are not usual pets, or restricting possession of dangerous animals, and in some cases have prohibited the keeping of L.quinquestriatus save by licensed zoos and educational facilities.

In several jurisdictions departments of fish and wildlife require permits for many animals,^[16][17] and a number of cities and municipal governments have prohibited their possession in their bylaws.^{[18][19][20][21][22]}

References

External links

Wikimedia Commons has media related to Leiurus quinquestriatus.

• Leiurus quinquestriatus, WikiPets