|Hottentotta tamulus from Mangaon, Maharashtra, India|
C. L. Koch, 1837
Scorpions are predatory arachnids of the order Scorpiones. They have eight legs and are easily recognized by the pair of grasping pedipalps and the narrow, segmented tail, often carried in a characteristic forward curve over the back, ending with a venomous stinger. Scorpions range in size from 9 mm / 0.3 in. (Typhlochactas mitchelli) to 23 cm / 9 in. (Heterometrus swammerdami).
The evolutionary history of scorpions goes back to the Silurian period 435 million years ago. They have adapted to a wide range of environmental conditions, and they can now be found on all continents except Antarctica. There are about 1,750 described species, with 13 extant (living) families recognised to date. Their taxonomy is being revised in the light of genomic studies.
All scorpions have a venomous sting, but the vast majority of the species do not represent a serious threat to humans, and in most cases, healthy adults do not need any medical treatment after being stung. Only about 25 species are known to have venom capable of killing a human. In some parts of the world with highly venomous species, human fatalities regularly occur, primarily in areas with limited access to medical treatment.
The word "scorpion" is thought to have originated in Middle English between 1175 and 1225 AD from Old French scorpion, or from Italian scorpione, both derived from the Latin scorpius, which is the romanization of the Greek word σκορπίος – skorpíos.
Scorpions are found on all major land masses except Antarctica and New Zealand. Scorpions did not occur naturally in Great Britain, Ireland, Japan, South Korea, and some of the islands in Oceania, but now have been accidentally introduced in some of these places by human trade and commerce. The greatest diversity of scorpions in the Northern Hemisphere is to be found in regions between the latitudes 23 and 38°N. Above these latitudes, the diversity decreases with the northernmost natural occurrence of scorpions being the northern scorpion Paruroctonus boreus at Medicine Hat, Alberta, Canada 50°N. Five colonies of scorpions (Euscorpius flavicaudis) have established themselves in Sheerness on the Isle of Sheppey in the United Kingdom. This small population has been resident since the 1860s, having probably arrived with imported fruit from Africa. This scorpion species is small and completely harmless to humans. At just over 51°N, this marks the northernmost limit where scorpions live in the wild.
Today, scorpions are found in virtually every terrestrial habitat including: high-elevation mountains, caves, and intertidal zones, with the exception of boreal ecosystems such as: the tundra, high-altitude taiga, and the permanently snow-clad tops of some mountains. As regards to microhabitats, scorpions may be ground-dwelling, tree-living, rock-loving or sand-loving. Some species, such as Vaejovis janssi, are versatile and are found in every type of habitat in Baja California, while others occupy specialized niches such as Euscorpius carpathicus, which is endemic to the littoral zone of rivers in Romania.
Scorpion fossils have been found in many strata, including marine Silurian and estuarine Devonian deposits, coal deposits from the Carboniferous Period and in amber. Whether the early scorpions were marine or terrestrial has been debated, though they had book lungs like modern terrestrial species.
The phylogeny of the scorpions has been debated, but genomic analysis consistently places the Bothriuridae as sister to a clade consisting of Scorpionoidea and "Chactoidea". The scorpions diversified between the Devonian and the early Carboniferous. The main division is into the clades Buthida and Iurida. The Bothriuridae diverged starting before temperate Gondwana broke up into separate land masses. The Iuroidea and Chactoidea are both broken up and are shown as "paraphyletic" (with quotation marks).
Thirteen families and about 1,750 described species and subspecies of scorpions are known. In addition, 111 described taxa of scorpions are extinct. This classification is based on that of Soleglad and Fet (2003), which replaced the older, unpublished classification of Stockwell. Additional taxonomic changes are from papers by Soleglad et al. (2005).
- Order Scorpiones
- Parvorder Pseudochactida Soleglad et Fet, 2003
- Parvorder Buthida Soleglad et Fet, 2003
- Parvorder Chaerilida Soleglad et Fet, 2003
- Parvorder Iurida Soleglad et Fet, 2003
- Superfamily Chactoidea Pocock, 1893
- Superfamily Iuroidea Thorell, 1876
- Superfamily Scorpionoidea Latreille, 1802
The body of a scorpion is divided into two parts (tagmata): the cephalothorax or prosoma, and the abdomen or opisthosoma.[a] The opisthosoma is subdivided into a broad anterior portion (called the mesosoma or pre-abdomen), and a narrow tail-like posterior (called the metasoma or post-abdomen).
The cephalothorax comprises the carapace, eyes, chelicerae (mouth parts), pedipalps (the pedipalps of scorpions have chelae, commonly called claws or pincers) and four pairs of walking legs. The scorpion's exoskeleton is thick and durable, providing good protection from predators. Scorpions have two eyes on the top of the cephalothorax, and usually two to five pairs of eyes along the front corners of the cephalothorax. While unable to form sharp images, their central eyes are amongst the most light sensitive in the animal kingdom, especially in dim light, and makes it possible for nocturnal species to use starlight to navigate at night. Some species also have light receptors in their tail. The position of the eyes on the cephalothorax depends in part on the hardness or softness of the soil upon which they spend their lives.
The pedipalp is a segmented, chelate (clawed) appendage used for prey immobilization, defense and sensory purposes. The segments of the pedipalp (from closest to the body outwards) are coxa, trochanter, femur (humerus), patella, tibia (including the fixed claw and the manus) and tarsus (moveable claw). A scorpion has darkened or granular raised linear ridges, called "keels" or carinae on the pedipalp segments and on other parts of the body, which are useful taxonomically.
The mesosoma is the broad part of the opisthosoma. Sometimes it is loosely called the abdomen. It consists of the anterior seven somites (segments) of the opisthosoma, each covered dorsally by a sclerotosed plate, its tergite. Ventrally somites 3 to 7 are armoured with matching plates called sternites.
Ventrally somites 1 and 2 are more complex; the first abdominal sternite is modified into a pair of genital opercula covering the gonopore. Sternite 2 forms the basal plate bearing the pectines. Morphologically the pectines are a pair of limbs that function as sensory organs.
The next four somites, 3 to 6, all bear pairs of spiracles. They serve as openings for the scorpion's respiratory organs, known as book lungs. The spiracle openings may be slits, circular, elliptical or oval according to the species of scorpion. There are thus four pairs of book lungs; each consists of some 140 to 150 thin lamellae filled with air inside a pulmonary chamber, connected on the ventral side to an atrial chamber which opens into a spiracle. Bristles hold the lamellae apart. A muscle opens the spiracle and widens the atrial chamber; dorsoventral muscles contract to compress the pulmonary chamber, forcing air out, and relax to allow the chamber to refill.
The 7th and last somite do not bear appendages or any other significant external structures.
The metasoma is commonly known as the scorpion's "tail", though this is in some ways misleading because unlike most so-called tails it is not an appendage or limb. It is in fact part of the opisthosoma. It comprises five segments, of which the fifth segment bears the telson. In many species, it superficially seems as though the metasoma has four segments only, because their first (anterior) metasomal segment gives the impression of being the posterior segment of the mesosoma. The fifth segment of the metasoma is the caudal segment of the opisthosoma, and accordingly bears the anus. The scorpion's telson is the part commonly called the stinger; it is attached to the end of the fifth segment just dorsad from the anus, but as the distal end of the tail at rest normally is carried upside down with the sting pointing forward, the anus usually is above the base of the telson and facing upwards.
The telson includes the vesicle, containing a symmetrical pair of venom glands. Externally it bears the curved sting, the hypodermic aculeus or venom-injecting barb. It is equipped with various sensory hairs, as the sting cannot be guided visually. Each of the venom glands has its own duct to convey its secretion internally along the aculeus from the bulb of the gland to immediately subterminal of the point of the aculeus, where each of the paired ducts has its own venom pore.
Scorpions prefer areas where the temperatures range from 20 to 37 °C (68 to 99 °F), but may survive temperatures ranging from well below freezing to desert heat. Scorpions of the genus Scorpiops living in high Asian mountains, bothriurid scorpions from Patagonia and small Euscorpius scorpions from Central Europe can all survive winter temperatures of about −25 °C (−13 °F). In Repetek (Turkmenistan), seven species of scorpion (of which Pectinibuthus birulai is endemic) live in temperatures varying from −31 to 50 °C (−24 to 122 °F).
Scorpions are nocturnal and fossorial, finding shelter during the day in the relative cool of underground holes or undersides of rocks, and emerging at night to hunt and feed. Scorpions exhibit photophobic behavior, primarily to evade detection by predators such as birds, lizards, rodents like the grasshopper mouse, opossums, and larger mammals including mongooses and the honey badger.
Scorpions are opportunistic predators of small arthropods, although the larger kinds have been known to kill small lizards and snakes. The large pincers are studded with highly sensitive tactile hair, and the moment an insect touches these, they use their chelae (pincers) to catch the prey. Depending on the toxicity of their venom and size of their claws, they then either crush the prey or inject it with neurotoxic venom. This kills or paralyzes the prey, so the scorpion can eat it. Scorpions have an unusual style of eating using chelicerae, small clawlike structures that protrude from the mouth that are unique to the Chelicerata among arthropods. The chelicerae, which are very sharp, are used to pull small amounts of food off the prey item for digestion into a pre-oral cavity below the chelicerae and carapace. Scorpions can ingest food only in a liquid form; they have external digestion. The digestive juices from the gut are egested onto the food and the digested food sucked in liquid form. Any solid indigestible matter (fur, exoskeleton, etc.) is trapped by setae in the pre-oral cavity and ejected by the scorpion.
Scorpions can consume large amounts of food at one sitting. They have an efficient food storage organ and a very low metabolic rate combined with a relatively inactive lifestyle. This enables scorpions to survive long periods when deprived of food. Some are able to survive 6 to 12 months of starvation. Scorpions excrete very little. Their waste consists mostly of insoluble nitrogenous compounds, such as xanthine, guanine and uric acid.
This section needs additional citations for verification. (June 2020) (Learn how and when to remove this template message)
Most scorpions reproduce sexually, and most species have male and female individuals; however, species in some genera, such as Hottentotta and Tityus, and the species Centruriodes gracilis, Liocheles australasiae, and Ananteris coineaui have been reported, not necessarily reliably, to reproduce through parthenogenesis, in which unfertilized eggs develop into living embryos.
Sexual reproduction is accomplished by the transfer of a spermatophore from the male to the female. Scorpions possess a complex courtship and mating ritual to effect this transfer. Mating starts with the male and female locating and identifying each other using a mixture of pheromones and vibrational communication. Once they have satisfied the other that they are of opposite sex and of the correct species, mating can commence.
The courtship starts with the male grasping the female's pedipalps with his own. The pair then perform a "dance" called the "promenade à deux". In this "dance," the male leads the female around searching for a suitable place to deposit his spermatophore. The courtship ritual can involve several other behaviors such as juddering and a cheliceral kiss, in which the male's chelicerae – pincers – grasp the female's in a smaller, more intimate version of the male's grasping the female's pedipalps, and in some cases injecting a small amount of his venom into her pedipalp or on the edge of her cephalothorax.
When the male has identified a suitable location, he deposits the spermatophore and then guides the female over it. This allows the spermatophore to enter her genital opercula, which triggers release of the sperm, thus fertilizing the female. The mating process can take from 1 to 25+ hours, and depends on the ability of the male to find a suitable place to deposit his spermatophore. If mating continues too long, the female may lose interest, ending the process.
Birth and development
Unlike the majority of species in the class Arachnida, which are oviparous, scorpions seem to be universally viviparous. The young are born one by one, expel the embryonic membrane, if any, and the brood is carried about on its mother's back until the young have undergone at least one molt. Before the first molt, scorplings cannot survive naturally without the mother, since they depend on her for protection and to regulate their moisture levels. Especially in species that display more advanced sociability (e.g. Pandinus spp.), the young/mother association can continue for an extended period of time. The size of the litter depends on the species and environmental factors, and can range from 2 to more than 100 scorplings. The average litter however, consists of around eight scorplings.
The young generally resemble their parents. Growth is accomplished by periodic shedding of the exoskeleton (ecdysis). A scorpion's developmental progress is measured in instars (how many molts it has undergone). Scorpions typically require between five and seven molts to reach maturity. Molting commences with a split in the old exoskeleton just below the edge of the carapace (at the front of the prosoma). The scorpion then emerges from this split. The pedipalps and legs are first removed from the old exoskeleton, followed eventually by the metasoma. When it emerges, the scorpion's new exoskeleton is soft, making the scorpion highly vulnerable to attack. The scorpion must constantly stretch while the new exoskeleton hardens to ensure that it can move when the hardening is complete. The process of hardening is called sclerotisation. The new exoskeleton does not fluoresce. As sclerotisation occurs, the fluorescence gradually returns.
Scorpions glow a vibrant blue-green when exposed to certain wavelengths of ultraviolet light such as that produced by a black light, due to the presence of fluorescent chemicals in the cuticle. One fluorescent component is beta-carboline. Accordingly, a hand-held UV lamp has long been a standard tool for nocturnal field surveys of these animals. Fluorescence occurs as a result of sclerotisation and increases in intensity with each successive instar. This fluorescence may have an active role in scorpion light detection.
Relationship with humans
In general, the venom is fast-acting, allowing for effective prey capture; however, as a general rule, scorpions kill their prey with brute force if they can, as opposed to using venom, which is also used as a defense against predators. The venom is a mixture of compounds (neurotoxins, enzyme inhibitors, etc.), each not only causing a different effect, but possibly also targeting a specific animal. Each compound is made and stored in a pair of glandular sacs and is released in a quantity regulated by the scorpion itself. Of the more than one thousand known species of scorpions, only 25 have venom that is deadly to humans; most of those belong to the family Buthidae (including Leiurus quinquestriatus, Hottentotta spp., Centruroides spp., and Androctonus spp.).
According to the US National Institute for Occupational Safety and Health, scorpion stings can largely be prevented by wearing long sleeves, long trousers, and leather gloves, and by shaking out clothing, bedding, bathroom towels, or shoes before using them. It recommends workers with a history of severe allergic reactions to insect bites or stings to consider carrying an epinephrine autoinjector (EpiPen), and states that they should wear a medical identification bracelet or necklace identifying their allergy.
First aid for scorpion stings is generally symptomatic. It includes strong analgesia, either systemic (opioids or paracetamol) or locally applied (such as a cold compress). Cases of very high blood pressure are treated with anxiety-relieving medications and medications which lower the blood pressure by widening the diameter of blood vessels. Scorpion envenomation with high morbidity and mortality is usually due to either excessive autonomic activity and cardiovascular toxic effects or neuromuscular toxic effects. Antivenom is the specific treatment for scorpion envenomation combined with supportive measures including vasodilators in patients with cardiovascular toxic effects and benzodiazepines when neuromuscular involvement occurs. Although rare, severe hypersensitivity reactions including anaphylaxis to scorpion antivenin (SAV) are possible.
Medical use of venom toxins
Short-chain scorpion toxins constitute the largest group of potassium (K+) channel-blocking peptides. An important physiological role of the KCNA3 channel, also known as KV1.3, is to help maintain large electrical gradients for the sustained transport of ions such as Ca2+ that controls T lymphocyte (T cell) proliferation. Thus KV1.3 blockers could be potential immunosuppressants for the treatment of autoimmune disorders (such as rheumatoid arthritis, inflammatory bowel disease, and multiple sclerosis). The venom of Uroplectes lineatus is clinically important in dermatology.
Several scorpion venom toxins have been investigated for medical use. Chlorotoxin from the deathstalker scorpion (Leiurus quinquestriatus); the toxin blocks small-conductance chloride channels; Maurotoxin from the venom of the Tunisian Scorpio maurus blocks potassium channels. Some antimicrobial peptides in the venom of Mesobuthus eupeus; meucin-13 and meucin-18 have extensive cytolytic effects on bacteria, fungi, and yeasts, while meucin-24 and meucin-25 selectively kill Plasmodium falciparum and inhibit the development of Plasmodium berghei, both malaria parasites, but do not harm mammalian cells.
Middle Eastern culture
The scorpion is a significant animal culturally, appearing as a motif in art, especially in Islamic art in the Middle East. A scorpion motif is often woven into Turkish kilim flat-weave carpets, for protection from their sting. The scorpion is perceived both as an embodiment of evil and a protective force such as a dervish's powers to combat evil. In another context, the scorpion portrays human sexuality. Scorpions are used in folk medicine in South Asia, especially in antidotes for scorpion stings.
Alongside serpents, scorpions are used to symbolize evil in the New Testament. In Luke 10:19 it is written, "Behold, I give unto you power to tread on serpents and scorpions, and over all the power of the enemy: and nothing shall by any means hurt you." Here, scorpions and serpents symbolize evil. Revelation 9:3 speaks of "the power of the scorpions of the earth."
The scorpion with its powerful sting has been used as the name or symbol of various products and brands, including Italy's Abarth racing cars. In the Roman army, the scorpio was a torsion siege engine used to shoot a projectile. The British Army's FV101 Scorpion was an armoured reconnaissance vehicle or light tank in service from 1972 to 1994. It holds the Guinness world record for the fastest production tank. A version of the Matilda II tank, fitted with a flail to clear mines, was named the Matilda Scorpion. Several ships of the Royal Navy have been named HMS Scorpion, including an 18-gun sloop in 1803, a turret ship in 1863, and a destroyer in 1910. A hand- or forearm-balancing asana in modern yoga as exercise with the back arched and one or both legs pointing forwards over the head is called Scorpion pose. A variety of martial arts films and video games have been entitled Scorpion King. A Montesa scrambler motorcycle was named Scorpion.
Scorpions have equally appeared in western artforms including film and poetry: the surrealist filmmaker Luis Buñuel made symbolic use of scorpions in his 1930 classic L'Age d'or (The Golden Age), while Stevie Smith's last collection of poems was entitled Scorpion and other Poems.
"Scorpion and snake fighting", Anglo-Saxon Herbal, c. 1050
Still life with scorpion and frog by Hermenegildo Bustos, 1874
- As there is currently neither paleontological nor embryological evidence that arachnids ever had a separate thorax-like division, there exists an argument against the validity of the term cephalothorax, which means fused cephalon (head) and the thorax. Similarly, arguments can be formed against use of the term abdomen, as the opistosoma of all scorpions contains a heart and book lungs, organs atypical of an abdomen.
- "Scorpion facts and information". ScorpionWorlds. Retrieved 19 February 2015.
- Rubio, Manny (2000). "Commonly Available Scorpions". Scorpions: Everything About Purchase, Care, Feeding, and Housing. Barron's. pp. 26–27. ISBN 978-0-7641-1224-9.
The Guinness Book of Records claims [...] Heterometrus swammerdami, to be the largest scorpion in the world [9 inches (23 cm)]
- Kovařík, František (2009). "Illustrated catalog of scorpions, Part I" (PDF). Retrieved 22 January 2011.
- "Diseases and Conditions – Scorpion stings". Mayo Clinic. Retrieved 3 July 2015.
- Polis 1990, p. 1.
- "Scorpion". American Heritage Dictionary (4th ed.). 2003. Retrieved April 14, 2010.
- "Scorpion". Dictionary.com. Random House. Retrieved April 14, 2010.
- σκορπιός, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus.
- Polis 1990, p. 249.
- Polis 1990, p. 251.
- Benton, T. G. (1992). "The ecology of the scorpion Euscorpius flavicaudis in England". Journal of Zoology. 226 (3): 351–368. doi:10.1111/j.1469-7998.1992.tb07484.x.
- Benton, T. G. (1991). "The life history of Euscorpius flavicaudis (Scorpiones, Chactidae)" (PDF). Journal of Arachnology. 19: 105–110.
- Rein, Jan Ove (2000). "Euscorpius flavicaudis". The Scorpion Files. Norwegian University of Science and Technology. Retrieved 2008-06-13.
- Polis 1990, pp. 251–252.
- Huber, Bernhard A.; Bradley J. Sinclair; K.-H. Lampe (2005). African biodiversity: molecules, organisms, ecosystems. Springer. p. 26. ISBN 978-0-387-24315-3.
- Ramel, Gordon. "The Earthlife Web: The Scorpions". The Earthlife Web. Retrieved 2010-04-08.
- s:The Scottish Silurian Scorpion. The Quarterly Journal of Microscopical Science. N. S. 1901. Vol. 44. pl. 19
- Howard, Richard J.; Edgecombe, Gregory D.; Legg, David A.; Pisani, Davide; Lozano-Fernandez, Jesus (2019). "Exploring the evolution and terrestrialization of scorpions (Arachnida: Scorpiones) with rocks and clocks". Organisms Diversity & Evolution. 19 (1): 71–86. doi:10.1007/s13127-019-00390-7. ISSN 1439-6092.
- Andrew Jeram (June 16, 1990). "When scorpions ruled the world". New Scientist.
- Gerhard Scholtz; Carsten Kamenz (2006). "The book lungs of Scorpiones and Tetrapulmonata (Chelicerata, Arachnida): evidence for homology and a single terrestrialisation event of a common arachnid ancestor". Zoology. 109 (1): 2–13. doi:10.1016/j.zool.2005.06.003. PMID 16386884.
- Jason A. Dunlop; O. Erik Tetlie; Lorenzo Prendini (2008). "Reinterpretation of the Silurian scorpion Proscorpius osborni (Whitfield): integrating data from Palaeozoic and recent scorpions". Palaeontology. 51 (2): 303–320. doi:10.1111/j.1475-4983.2007.00749.x.
- G. Kühl; A. Bergmann; J. Dunlop; R. J. Garwood; J. Rust (2012). "Redescription and palaeobiology of Palaeoscorpius devonicus Lehmann, 1944 from the Lower Devonian Hunsrück Slate of Germany". Palaeontology. 55 (4): 775–787. doi:10.1111/j.1475-4983.2012.01152.x.
- Gess, R. W. (2013). "The earliest record of terrestrial animals in Gondwana: a scorpion from the Famennian (Late Devonian) Witpoort Formation of South Africa". African Invertebrates. 54 (2): 373–379. doi:10.5733/afin.054.0206.
- Dunlop, Jason A.; David Penney; O. Erik Tetlie; Lyall I. Anderson (2008). "How many species of fossil arachnids are there" (PDF). Journal of Arachnology. 36 (2): 262–272. doi:10.1636/CH07-89.1.
- Sharma, Prashant P.; Baker, Caitlin M.; Cosgrove, Julia G.; Johnson, Joanne E.; Oberski, Jill T.; Raven, Robert J.; Harvey, Mark S.; Boyer, Sarah L.; Giribet, Gonzalo (2018). "A revised dated phylogeny of scorpions: Phylogenomic support for ancient divergence of the temperate Gondwanan family Bothriuridae". Molecular Phylogenetics and Evolution. 122: 37–45. doi:10.1016/j.ympev.2018.01.003. ISSN 1055-7903.
- Soleglad, Michael E.; Victor Fet (2003). "High-level systematics and phylogeny of the extant scorpions (Scorpiones: Orthosterni)" (multiple parts). Euscorpius. 11: 1–175. Retrieved 2008-06-13.
- Scott A. Stockwell (1989). Revision of the Phylogeny and Higher Classification of Scorpions (Chelicerata). Ph.D. Dissertation, University of California, Berkeley
- Michael E. Soleglad; Victor Fet; F. Kovařík (2005). "The systematic position of the scorpion genera Heteroscorpion Birula, 1903 and Urodacus Peters, 1861 (Scorpiones: Scorpionoidea)" (PDF). Euscorpius. 20: 1–38. Retrieved 2008-06-13.
- V. Fet; E. Soleglad (2005). "Contributions to scorpion systematics. I. On recent changes in high-level taxonomy" (PDF). Euscorpius (31): 1–13. ISSN 1536-9307. Retrieved 2010-04-07.
- Shultz, Stanley; Shultz, Marguerite (2009). The Tarantula Keeper's Guide. Hauppauge, New York: Barron's. p. 23. ISBN 978-0-7641-3885-0.
- Polis 1990, p. 10.
- Arthropod Diversity and Conservation in the Tropics and Sub-tropics
- "Department of Entomology". Texas A&M University. Archived from the original on 1999-08-22. Retrieved 2012-05-03.
- "WRBU Scorpion Identification". Wrbu.org. Retrieved 2012-05-03.
- Polis 1990, p. 12.
- Knowlton, E. D., Gaffin, D. D. (June, 2011) "Functionally redundant peg sensilla on the scorpion pecten", NCBI.
- Polis 1990, pp. 13–15.
- Evolutionary Developmental Biology of Invertebrates 3 Ecdysozoa I: Non-Tetraconata
- Polis 1990, p. 21.
- Polis 1990, p. 15.
- Polis 1990, p. 9.
- Yigit, N. Benli, M. Fine structural analysis of the stinger in venom apparatus of the scorpion Euscorpius mingrelicus. Journal of Venom and Animal Toxins including Tropical Diseases V.16, n.1, p.76-86, 2010. ISSN 1678-9199.
- Hadley, Neil F. (1970). "Water relations of the desert scorpion, Hadrurus arizonensis" (PDF). Journal of Experimental Biology. 53 (3): 547–558. PMID 5487163.
- Hoshino, K.; A. T. V. Moura; H. M. G. De Paula (2006). "Selection of environmental temperature by the yellow scorpion Tityus serrulatus Lutz & Mello, 1922 (Scorpiones, Buthidae)" (PDF). Journal of Venomous Animals and Toxins Including Tropical Diseases. 12 (1): 59–66. doi:10.1590/S1678-91992006000100005.
- Kovařík, František (1998). Štíři [Scorpions] (in Czech). Jihlava: Madagaskar. p. 19. ISBN 978-80-86068-10-7.
- "Scorpions". Australian Museum. Archived from the original on 2009-03-02. Retrieved 2008-06-13.
- Polis 1990, pp. 296–297.
- Polis 1990, pp. 297–298.
- Lourenço, W. R. (2008). "Parthenogenesis in scorpions: some history - new data". Journal of Venomous Animals and Toxins including Tropical Diseases. 14 (1). doi:10.1590/S1678-91992008000100003. ISSN 1678-9199.
- Hickman, Cleveland P., Jr.; Larry S. Roberts; Allan Larson; Helen I'Anson; David Eisenhour (2005-02-01). Integrated Principles of Zoology (13 ed.). McGraw-Hill Science/Engineering/Math. p. 380. ISBN 978-0-07-310174-3.
- Peretti, A. (1999). "Sexual cannibalism in scorpions: fact or fiction?". Biological Journal of the Linnean Society. 68 (4): 485–496. doi:10.1111/j.1095-8312.1999.tb01184.x. ISSN 0024-4066.
- Warburg, M. R. (2012). "Pre-and post-parturial aspects of scorpion reproduction: a review". European Journal of Entomology. 109 (2): 139–46. doi:10.14411/eje.2012.018.
- Lourenco, W. R. (2000). "Reproduction in scorpions, with special reference to parthenogenesis" (PDF). In S. Toft; N. Scharff (eds.). European Arachnology. Aarhus University Press. pp. 71–85. ISBN 978-877934-0015.
- Stachel, Shawn J.; Scott A. Stockwell; David L. Van Vranken (August 1999). "The fluorescence of scorpions and cataractogenesis". Chemistry & Biology. 6 (8): 531–539. doi:10.1016/S1074-5521(99)80085-4. PMID 10421760.
- Gaffinr, Douglas D.; Lloyd A. Bumm; Matthew S. Taylor; Nataliya V. Popokina; Shivani Mann (2012). "Scorpion fluorescence and reaction to light" (PDF). Animal Behaviour. 83 (2): 429–436. doi:10.1016/j.anbehav.2011.11.014.
- Rodríguez de la Vega, Ricardo C.; Nicolas Vidal; Lourival D. Possani (2013). "Scorpion Peptides". In Abba J. Kastin (ed.). Handbook of Biologically Active Peptides (2nd ed.). pp. 423–429. doi:10.1016/B978-0-12-385095-9.00059-2. ISBN 978-0-12-385095-9.
- "Poisonous Animals: Scorpions". ThinkQuest. 2000. Archived from the original on 2005-04-03. Retrieved December 16, 2009.
- "Insects and Scorpions". NIOSH. 1 July 2016. Retrieved 15 July 2016.
- Buma, Adriaan Hopperus; David G. Burris; Alan Hawley; James M. Ryan; Peter F. Mahoney (2009). "Scorpion sting". Conflict and Catastrophe Medicine: A Practical Guide (2nd ed.). Springer. p. 518. ISBN 978-1-84800-351-4.
- Bhoite, R. R.; Bhoite, G.R.; Bagdure, D. N.; Bawaskar, H. S. (2015). "Anaphylaxis to scorpion antivenin and its management following envenomation by Indian red scorpion, Mesobuthus tamulus". Indian Journal of Critical Care Medicine. 19 (9): 547–549. doi:10.4103/0972-5229.164807. PMC 4578200. PMID 26430342.
- DeBin, J. A.; G. R. Strichartz (1991). "Chloride channel inhibition by the venom of the scorpion Leiurus quinquestriatus". Toxicon. 29 (11): 1403–1408. doi:10.1016/0041-0101(91)90128-E. PMID 1726031.
- Chandy, K. George; Heike Wulff; Christine Beeton; Michael Pennington; George A. Gutman; Michael D. Cahalan (May 2004). "K+ channels as targets for specific immunomodulation". Trends in Pharmacological Sciences. 25 (5): 280–289. doi:10.1016/j.tips.2004.03.010. PMC 2749963. PMID 15120495.
- Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007). Dermatology: 2-Volume Set. St. Louis: Mosby. p. 1315. ISBN 978-1-4160-2999-1.
- Deshane, Jessy; Craig C. Garner; Harald Sontheimer (2003). "Chlorotoxin inhibits glioma cell invasion via matrix metalloproteinase-2". Journal of Biological Chemistry. 278 (6): 4135–4144. doi:10.1074/jbc.M205662200. PMID 12454020.
- Carlier, E.; S. Geib; M. De Waard; V. Avdonin; T. Hoshi; Z. Fajloun; H. Rochat; J.-M. Sabatier; R. Kharrat (2000). "Effect of maurotoxin, a four disulfide-bridged toxin from the chactoid scorpion Scorpio maurus, on Shaker K+ channels". The Journal of Peptide Research. 55 (6): 419–427. doi:10.1034/j.1399-3011.2000.00715.x. PMID 10888198.
- Gao, Bin; Patrick Sherman; Lan Luo; John Bowie; Shunyi Zhu (2009). "Structural and functional characterization of two genetically related meucin peptides highlights evolutionary divergence and convergence in antimicrobial peptides". FASEB Journal. 23 (4): 1230–1245. doi:10.1096/fj.08-122317. PMID 19088182.
- Gao, Bin; Jia Xu; Maria del Carmen Rodriguez; Humberto Lanz-Mendoza; Rosaura Hernández-Rivas; Weihong Du; Shunyi Zhu (2010). "Characterization of two linear cationic antimalarial peptides in the scorpion Mesobuthus eupeus". Biochimie. 92 (4): 350–359. doi:10.1016/j.biochi.2010.01.011. PMID 20097251.
- Forney, Matthew (June 11, 2008). "Scorpions for Breakfast and Snails for Dinner". The New York Times.
- Frembgen, Jürgen Wasim (2004). "The scorpion in Muslim folklore". Asian Folklore Studies. 63 (1): 95–123.
- Erbek, Güran (1998). Kilim Catalogue No. 1 (1st ed.). May Selçuk A. S.
- Polis 1990, p. 462.
- "Pharaonic Gods". Egyptian Museum. 13 May 2008. Archived from the original on 13 May 2008.
- Pulpit Commentary on Luke 10, accessed 29 October 2018
- Revelation 9:3
- "Abarth Logo: Design and History". Famouslogos.net. Archived from the original on 11 June 2013. Retrieved 2011-07-28.
- Vitruvius, De Architectura, X:10:1-6.
- "FV101 Scorpion: Keeping the Light Tank Relevant". HistoryNet. Retrieved 23 June 2020.
- "Fastest tank". Guinnessworldrecords.com. 26 March 2002. Retrieved 31 May 2014.
- Fletcher, David (2017). British Battle Tanks: British-made Tanks of World War II. Bloomsbury. p. 37. ISBN 978-1-4728-2003-7.
- Winfield, Rif (2008). British Warships in the Age of Sail 1793–1817: Design, Construction, Careers and Fates. Seaforth. p. 291. ISBN 978-1-86176-246-7.
- Parkes, Oscar (1990). British Battleships (reprint of the 1957 ed.). Annapolis, MD: Naval Institute Press. pp. 78–79. ISBN 1-55750-075-4.
- The Times (London), Wednesday, 31 August 1910, p. 5
- YJ Editors; Budig, Kathryn (1 October 2012). "Kathryn Budig Challenge Pose: Scorpion in Forearm Balance". Yoga Journal.
- Wallis, J. Doyle (2004). "Operation Scorpio". DVD Talk. Retrieved 2015-06-19.
- "The Scorpion King". Box Office Mojo. Retrieved 4 January 2010.
- Provo, Frank (2002). "The Scorpion King: Sword of Osiris Review". GameSpot. Retrieved 24 June 2020.
- Salvadori, Clement (17 January 2019). "Retrospective: 1974-1977 Montesa Cota 247-T". Rider Magazine. Retrieved 25 June 2020.
Permanyer persisted, built larger engines, and in 1965 showed the 247cc engine (21 horsepower at 7,000 rpm) in a Scorpion motocrosser.
- Weiss, Allen S. (1996). "Between the sign of the scorpion and the sign of the cross: L'Age d'or". In Rudolf E. Kuenzli (ed.). Dada and Surrealist Film. MIT Press. pp. 159–175. ISBN 978-0-262-61121-3.
- "Stevie Smith: Bibliography". Poetry Foundation. Retrieved 1 July 2019.
- Polis, Gary (1990). The Biology of scorpions. Stanford University Press. ISBN 978-0-8047-1249-1. OCLC 18991506.
|Wikispecies has information related to Scorpiones|
|Wikimedia Commons has media related to:|