Wednesday, 23 September 2015

Death Stalker Scorpion


Contrarily to the popular belief most of the scorpions are relatively harmless to humans as stings produce only local effects (pain, numbness or swelling). However, the Death Starker Scorpion is highly dangerous species because its venom is a powerful cocktail of neurotoxins which causes an intense and unbearable pain, then fever, followed by coma, convulsions, paralysis and death. Fortunately, while a sting from this scorpion is extremely painful, it would be unlikely to kill a healthy, adult human. Young children, the old, or infirm (with a heart condition) are at the biggest risk.
Death stalker scorpions are spread in North Africa and Middle East.
The deathstalker (Leiurus quinquestriatus), is a species of scorpion, a member of the Buthidae family. It is also known as the Israeli yellow scorpion, 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 nameLeiurus quinquestriatus roughly translates into English as "five-striped smooth-tail". Other species of the genus Leiurus are also often referred to as "deathstalkers".

Description[edit]

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[edit]

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, Libya, Mali, Niger, Somalia, Sudan, Tunisia, Iraq, Jordan, Kuwait, Lebanon, Oman, Iran, Afghanistan, Israel, Pakistan, India, Qatar, Saudi Arabia, Syria, Turkey, Kazakhstan, Uzbekistan, United Arab Emirates, and Yemen.

Venom[edit]

A deathstalker eating a cricket in captivity
Neurotoxins in L. quinquestriatus venom include:

Hazards[edit]

The deathstalker is regarded as the most dangerous species of scorpion. Its venomis 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-threateningallergic reaction to the venom. A study from Israel shows a high rate of pancreatitis following envenomation.[7] If a sting fromLeiurus 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[edit]

Main article: Chlorotoxin
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[citation needed].
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[edit]

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[edit]

  1. Jump up^ Minton, Sherman A. (1974). Venom diseases. Thomas. p. 235. ISBN 978-0-398-03051-3. Retrieved April 30, 2010.
  2. Jump up^ The Staff of Cambridge Scientific Abstracts (1993). Entomology abstracts, Volume 24, Issues 10-12. Cambridge Scientific Abstracts. Retrieved April 30, 2010.
  3. Jump up^ Werness, Hope B. (2004). The Continuum encyclopedia of animal symbolism in art. Continuum International Publishing Group. p. 476. ISBN 978-0-8264-1525-7. Retrieved April 30, 2010.
  4. Jump up^ Young, Mark (1998). The Guinness Book of World Records 1998. Bantam Books. p. 768. ISBN 978-0-553-57895-9. Retrieved April 30, 2010.
  5. Jump up^ Zuhair S. Amr & Ratib El-Oran (1994). "Systematics and distribution of scorpions (Arachnida, Scorpionida) in Jordan". Italian Journal of Zoology 61 (2): 185–190. doi:10.1080/11250009409355881.
  6. Jump up^ Lucian K. Ross (2008). "Leiurus quinquestriatus (Ehrenberg, 1828)" (PDF). The Scorpion Files. Retrieved September 17,2011.
  7. Jump up^ http://www.ncbi.nlm.nih.gov/pubmed/2028471
  8. Jump up^ "Scorpion Antivenom Twyford (North Africa)". MAVIN. Poison Centre Munich. January 15, 2010. Retrieved December 1,2010.
  9. Jump up^ "Scorpifav". MAVIN. Poison Centre Munich. January 15, 2010. Retrieved December 1, 2010.
  10. Jump up^ "Saudi National Antivenom and Vaccine Production Center". Retrieved December 1, 2010.
  11. Jump up^ Goldfrank, Lewis R. (2006). Goldfrank's toxicologic emergencies. McGraw-Hill Professional. p. 2064. ISBN 978-0-07-147914-1. Retrieved November 23, 2010.
  12. Jump up^ Eric A. Shalita & Ryan D. Wells (2007). "Treatment of yellow scorpion (Leiurus quinquestriatus) sting: a case report". Journal of the American Pharmacists Association 47 (5): 616–619. doi:10.1331/JAPhA.2007.07051. PMID 17848352.
  13. Jump up^ "Antivenom: Species Covered" (PDF). Miami-Dade Fire Rescue Department. January 2009. Retrieved December 1, 2010.
  14. Jump up^ Liliana Soroceanu, Yancey Gillespie, M. B. Khazaeli & Harald Sontheimer (1998). "Use of chlorotoxin for targeting of primary brain tumors". Cancer Research 58 (21): 4871–4879. PMID 9809993.
  15. Jump up^ Guardian newspaper: How to light up a tumour, 10 September 2015
  16. Jump up^ "Wild Bird and Animal Importation and Possession" (PDF). Vermont Fish and Wildlife Department. August 2010. RetrievedApril 25, 2013. |chapter= ignored (help)
  17. Jump up^ In the UK a licence is required under the 1976 Dangerous Wild Animals Act
  18. Jump up^ "Ordinance No: 07-02. Public Nuisance Ordinance" (PDF). Town of Morrison, Brown County, Wisconsin. Retrieved April 25,2013.
  19. Jump up^ "Licensing of dogs and cats; regulation of animals" (PDF). Village of Pulaski, Wisconsin. Archived from the original (PDF)on July 11, 2012. Retrieved April 25, 2013.
  20. Jump up^ "Public Health and Welfare" (PDF). City of Green Bay, Wisconsin. Archived from the original (PDF) on March 11, 2012. Retrieved April 25, 2013.
  21. Jump up^ "Animal Ordinances Revision as of 4/11/05 passed at 4/11/05Council Mtg." (PDF). City of Brooklyn, Ohio. Archived from the original (PDF) on May 17, 2011. Retrieved April 25, 2013.
  22. Jump up^ "Animal Ordinance Draft" (DOC). Town of Rockland, Brown County, Wisconsin. November 28, 2007. Retrieved April 25, 2013.
Posted by at 1 comment:

Blue-Ringed Octopus


(Image credits: Tom Weilenmann)
The Blue-Ringed Octopus is very small, only the size of a golf ball, but its venom is so powerful that can kill a human. Actually it carries enough poison to kill 26 adult humans within minutes, and there is no antidote. They are currently recognized as one of the world’s most venomous animals.
Its painless bite may seem harmless, but the deadly neurotoxins begin working immediately resulting in muscular weakness, numbness, followed by a cessation and breathing and ultimately death.
They can be found in tide pools in the Pacific Ocean, from Japan to Australia.
The blue-ringed octopuses (genus Hapalochlaena) are three (or perhaps four)octopus species that live in tide pools and coral reefs in the Pacific and Indian Oceans, from Japan to Australia. Their primary habitat is around southern New South Wales, South Australia, and northern Western Australia.[1][2] They are recognized as one of the world's most venomous marine animals.[3] Despite their small size, 12 to 20 cm (5 to 8 in), and relatively docile nature, they are dangerous to humans if provoked and handled, because their venom is powerful enough to killhumans.
They can be identified by their characteristic blue and black rings, and yellowish skin. When the octopus is agitated, the brown patches darken dramatically, iridescent blue rings, or clumps of rings, appear and pulsate within the maculae. Typically, 50–60 blue rings cover the dorsal and lateral surfaces of the mantle.
They hunt small crabs, hermit crabs, and shrimp.

Classification[edit]

The genus was described by British zoologist Guy Coburn Robson in 1929.[4]There are four confirmed species of Hapalochlaena, and six possible species still being researched:[5]

Behavior[edit]

An individual blue-ringed octopus tends to use its dermal chromatophore cells to camouflage itself until provoked, at which point it quickly changes color, becoming bright yellow with blue rings or lines. The blue-ringed octopus spends much of its life hiding in crevices. Like all octopuses, it can change its shape easily, which helps it to squeeze into crevices much smaller than itself. This helps safeguard the octopus from predators and it may even pile up rocks outside the entrance to its lair. In common with Octopoda, the blue-ringed octopus swims by expelling water from its funnel in a form of jet propulsion.

Feeding[edit]

The blue-ringed octopus diet typically consists of small crabs, and shrimp, but they may also feed on fish if they can catch them. The blue-ringed octopus pounces on its prey, seizing it with its arms and pulling it towards its mouth. It uses its horny beak to pierce through the tough crab or shrimp exoskeleton, releasing its venom. The venom paralyzes the muscles required for movement, which effectively kills the prey.

Reproduction[edit]

The mating ritual for the blue-ringed octopus begins when a male approaches a female and begins to caress her with his modified arm, the hectocotylus. A male mates with a female by grabbing her, which sometimes completely obscures the female's vision, then transferring sperm packets by inserting his hectocotylus into her mantle cavity repeatedly. Mating continues until the female has had enough, and in at least one species the female has to remove the over-enthusiastic male by force. Males will attempt copulation with members of their own species regardless of sex or size, but interactions between males are most often shorter in duration and end with the mounting octopus withdrawing the hectocotylus without packet insertion or struggle.[6]
Blue-ringed octopus females lay only one clutch of about 50 eggs in their lifetimes towards the end of autumn. Eggs are laid then incubated underneath the female's arms for about six months, and during this process she does not eat. After the eggs hatch, the female dies, and the new offspring will reach maturity and be able to mate by the next year.

Toxicity[edit]

The blue-ringed octopus, despite its small size, carries enough venom to kill 26 adult humans within minutes. Their bites are tiny and often painless, with many victims not realizing they have been envenomated until respiratory depression andparalysis start to set in.[7] No blue-ringed octopus antivenom is available yet, making it one of the deadliest reef inhabitants in the ocean.

Venom[edit]

Blue-ringed octopus from New South Wales, Australia
The octopus produces venom containing tetrodotoxin, histamine, tryptamine,octopamine, taurine, acetylcholine, and dopamine. The venom can result in nausea,respiratory arrest, heart failure, severe and sometimes total paralysis, blindness, and can lead to death within minutes if not treated. Death, if it occurs, is usually from suffocation due to paralysis of the diaphragm.
The major neurotoxin component of the blue-ringed octopus is a compound that was originally known as maculotoxin but was later found to be identical to tetrodotoxin,[8]a neurotoxin also found in pufferfish, and in some poison dart frogs.[9] Tetrodotoxin is 1,200 times more toxic than cyanide.[10] Tetrodotoxin blocks sodium channels, causing motor paralysis, and respiratory arrest within minutes of exposure. The tetrodotoxin is produced by bacteria in the salivary glands of the octopus.[11]
A person has to be in contact with the octopus to be envenomated. The octopus's first instinct is to flee. If the threat persists, the octopus will go into a defensive stance, and show its blue rings. Only if cornered, and touched, will a person be in danger of being bitten and envenomated.

Effects[edit]

Tetrodotoxin causes severe and often total body paralysis. Tetrodotoxin envenomation can result in victims being fully aware of their surroundings but unable to breathe. Because of the paralysis that occurs, they have no way of signaling for help or any way of indicating distress. The victim remains conscious and alert in a manner similar to curare or pancuronium bromide. This effect, however, is temporary and will fade over a period of hours as the tetrodotoxin is metabolized and excreted by the body.
The symptoms vary in severity, with children being the most at risk because of their small body size.

Treatment[edit]

First aid treatment is pressure on the wound and artificial respiration once the paralysis has disabled the victim's respiratory muscles, which often occurs within minutes of being bitten. Because the venom primarily kills through paralysis, victims are frequently saved if artificial respiration is started and maintained before marked cyanosis and hypotension develop. Efforts should be continued even if the victim appears not to be responding. Respiratory support, together with reassurance, until medical assistance arrives ensures the victims will generally recover well.
It is essential that rescue breathing be continued without pause until the paralysis subsides and the victim regains the ability to breathe on their own. This is a daunting physical prospect for a single individual, but use of a bag valve mask respirator reduces fatigue to sustainable levels until help can arrive.
Definitive hospital treatment involves placing the patient on a medical ventilator until the toxin is removed by the body.
Victims who survive the first 24 hours usually recover completely.[12]

Popular culture[edit]

The Blue-ringed Octopus is the prominent symbol of the secret order of female bandits and smugglers in the James Bondfilm Octopussy, appearing in an aquarium tank, on silk robes, and as a tattoo on women in the order.[13][14]

References[edit]

  1. Jump up^ Surf Lifesaving Training Manual, 32nd edition
  2. Jump up^ CBS News http://www.cbsnews.com/8301-202_162-57591718/tiny-but-deadly-spike-in-blue-ringed-octopus-sightings-sparks-fear-of-invasion-in-japan/
  3. Jump up^ "Ocean's Deadliest: The Deadliest Creatures -- Greater Blue-Ringed Octopus". Animal Planet.
  4. Jump up^ Robson, G. C. (1929). "Notes on the Cephalopoda. - VIII. The genera and subgenera of Octopodinae and Bathypolypodinae".Annals and Magazine of Natural History: Series 10 3 (18): 607–608. doi:10.1080/00222932908673017.
  5. ^ Jump up to:a b Rudramurthy, N.; Sethi, S. N. (November 2013). "Blue ring Octopus, Hapalochlaena nierstraszi, from the Bay of Bengal along the Chennai Coast". Fishing Chimes 33 (82-83).
  6. Jump up^ Cheng, M.W. & R.L. Caldwell 2000. Sex identification and mating in the blue-ringed octopus, Hapalochlaena lunulata. Anim Behav. 60(1): 27-33.
  7. Jump up^ "Dangers on the Barrier Reef". Archived from the original on 2006-12-05. Retrieved 2006-12-06.
  8. Jump up^ Sheumack DD, Howden ME, Spence I, Quinn RJ (1978). "Maculotoxin: a neurotoxin from the venom glands of the octopus Hapalochlaena maculosa identified as tetrodotoxin". Science 199 (4325): 188–9. doi:10.1126/science.619451.PMID 619451.
  9. Jump up^ Daly, J.W., Gusovsky, F., Myers, C.W., Yotsuyamashita, M., and Yasumoto, T. (1994). "1st Occurrence of Tetrodotoxin in a Dendrobatid Frog (Colostethus-Inguinalis), with Further Reports for the Bufonid Genus Atelopus". Toxicon 32 (3): 279–285.doi:10.1016/0041-0101(94)90081-7. PMID 8016850.
  10. Jump up^ Furlow, Bryant. "Tetrodotoxin and the Life Tree". Retrieved 2011-04-22.
  11. Jump up^ Dr. Roy Caldwell. "What makes blue-rings so deadly?". Retrieved 2007-03-19.
  12. Jump up^ Lippmann, John and Bugg, Stan, "DAN S.E. Asia-Pacific Diving First Aid Manual", J.L. Publications, Australia, May 2004.ISBN 0-646-23183-9
  13. Jump up^ http://www.imdb.com/title/tt0086034/trivia
  14. Jump up^ http://www.cbsnews.com/news/tiny-but-deadly-spike-in-blue-ringed-octopus-sightings-sparks-fear-of-invasion-in-japan/
Posted by at No comments:
Subscribe to: Posts (Atom)