Editing Scorpion (section)

==Biology==

[[File:Scorpion Centruroides limpidus (14587304901).jpg|thumb|''[[Centruroides limpidus]]'' in its rocky shelter]]

Most scorpion species are [[nocturnal]] or [[crepuscular]], finding shelter during the day in burrows, cracks in rocks and tree bark.{{sfn|Stockmann|2015|pp=40–41}} Many species dig a shelter underneath stones a few centimeters long. Some may use burrows made by other animals including spiders, reptiles and small mammals. Other species dig their own burrows which vary in complexity and depth. ''[[Hadrurus]]'' species dig burrows as over {{convert|2|m|abbr=on}} deep. Digging is done using the mouth parts, claws and legs. In several species, particularly of the family Buthidae, individuals may gather in the same shelter; bark scorpions may aggregate up to 30 individuals. In some species, families of females and young sometimes aggregate.{{sfn|Stockmann|Ythier|2010|pp=146, 153–154}}

Scorpions prefer areas where the temperature remains in the range of {{convert|11|–|40|C|F}}, but may survive temperatures from well below freezing to desert heat.<ref>{{cite journal |last=Hadley |first=Neil F. |title=Water Relations of the Desert Scorpion, ''Hadrurus arizonensis'' |journal=[[Journal of Experimental Biology]] |year=1970 |volume=53 |issue=3 |pages=547–558 |doi=10.1242/jeb.53.3.547 |url=https://journals.biologists.com/jeb/article/53/3/547/21677/Water-Relations-of-the-Desert-Scorpion-Hadrurus |pmid=5487163 |bibcode=1970JExpB..53..547H |access-date=30 December 2006 |archive-date=6 April 2008 |archive-url=https://web.archive.org/web/20080406195500/http://jeb.biologists.org/cgi/reprint/53/3/547.pdf |url-status=live }}</ref><ref>{{cite journal |last1=Hoshino |first1=K. |last2=Moura |first2=A. T. V. |last3=De Paula |first3=H. M. G. |title=Selection of Environmental Temperature by the Yellow Scorpion ''Tityus serrulatus'' Lutz & Mello, 1922 (Scorpiones, Buthidae) |journal=Journal of Venomous Animals and Toxins Including Tropical Diseases |year=2006 |volume=12 |issue=1 |pages=59–66 |doi=10.1590/S1678-91992006000100005 |doi-access=free |hdl=11449/68851 |hdl-access=free }}</ref> Scorpions can withstand intense heat: ''[[Leiurus quinquestriatus]]'', ''Scorpio maurus''<!--linked above--> and ''[[Hadrurus arizonensis]]'' can live in temperatures of {{convert|45|–|50|C|F|0|abbr=on}} if they are sufficiently hydrated. Desert species must deal with the extreme changes in temperature from day to night or between seasons; ''[[Pectinibuthus birulai]]'' lives in a temperature range of {{convert|-30|–|50|C|F|0|abbr=on}}. Scorpions that live outside deserts prefer lower temperatures. The ability to resist cold may be related to the increase in the sugar [[trehalose]] when the temperature drops. Some species [[hibernate]].{{sfn|Stockmann|2015|pp=42–43}} Scorpions are resistant to [[ionizing radiation]], surviving nuclear tests in Algeria{{sfn|Stockmann|Ythier|2010|p=157}} and Nevada.<ref>{{Cite journal |last=Allred |first=Dorald M. |date=1973 |title=Effects of a Nuclear Detonation on Arthropods at the Nevada Test Site |url=https://scholarsarchive.byu.edu/byuscib/vol18/iss4/1?utm_source=scholarsarchive.byu.edu%2Fbyuscib%2Fvol18%2Fiss4%2F1&utm_medium=PDF&utm_campaign=PDFCoverPages |journal=Brigham Young University Science Bulletin |volume=18 |issue=4 |pages=1–20 |via=BYU SchoalarsArchive}}</ref>

Desert scorpions have several adaptations for water conservation. They excrete insoluble compounds such as [[xanthine]], [[guanine]], and [[uric acid]], not requiring water for their removal from the body. Guanine is the main component and maximizes the amount of nitrogen excreted. A scorpion's cuticle holds in moisture via [[lipid]]s and waxes from epidermal glands, and protects against [[ultraviolet radiation]]. Even when dehydrated, a scorpion can tolerate high [[osmotic pressure]] in its blood.<ref>{{cite book |last=Cowles |first=Jillian |title=Amazing Arachnids |publisher=Princeton University Press |year=2018 |page=33 |isbn=978-0-691-17658-1}}</ref> Desert scorpions get most of their moisture from the food they eat but some can absorb water from the humid soil. Species that live in denser vegetation and in more moderate temperatures will drink water on plants and in puddles.{{sfn|Stockmann|Ythier|2010|p=156}}
[[File:Venom Squirting in Scorpions.svg|thumb|upright=0.9|A few scorpions squirt [[venom]] to deter predators.]]
A scorpion uses its stinger both for killing prey and defense. Some species make direct, quick strikes with their tails while others make slower, more circular strikes which can more easily return the stinger to a position where it can strike again. ''Leiurus quinquestriatus'' can whip its tail at a speed of up to {{convert|128|cm/s|in/s|abbr=on}}<!--Coelho et al, table 3--> in a defensive strike.<ref>{{cite journal |last1=Coelho |first1=P. |last2=Kaliontzopoulou |first2=A. |last3=Rasko |first3=M. |last4=van der Meijden |first4=A. |year=2017 |title=A 'Striking' Relationship: Scorpion Defensive Behaviour and its Relation to Morphology and Performance |journal=Functional Ecology |volume=31|issue=7 |pages=1390–1404 |doi=10.1111/1365-2435.12855|doi-access=free |bibcode=2017FuEco..31.1390C }}</ref>

===Mortality and defense===

Scorpions may be attacked by other arthropods like ants, spiders, [[solifugids]] and [[centipede]]s. Major [[predator]]s include frogs, lizards, snakes, birds, and mammals.{{sfn|Stockmann|2015|pp=36–37}} [[Meerkat]]s are somewhat specialized in preying on scorpions, biting off their stingers and being immune to their venom.<ref name=ms>{{cite journal |title=''Suricata suricatta'' |journal=Mammalian Species |issue=483 |pages=1–8 |date=1994 |last=Van Staaden |first=M. J. |jstor=3504085 |doi=10.2307/3504085 |url=http://www.science.smith.edu/msi/pdf/i0076-3519-483-01-0001.pdf |url-status=dead |archive-date=15 March 2016 |archive-url=https://web.archive.org/web/20160315210848/http://www.science.smith.edu/msi/pdf/i0076-3519-483-01-0001.pdf}}</ref><ref>{{cite journal |last1=Thornton |first1=A. |first2=K. |last2=McAuliffe |date=2006 |title=Teaching in wild meerkats |journal=Science |volume=313 |issue=5784 |pages=227–229 |doi= 10.1126/science.1128727 |pmid=16840701|bibcode=2006Sci...313..227T |s2cid=11490465 |url=https://pdfs.semanticscholar.org/cd30/5c0e32d229d45a2350db58e9ab79ce48761c.pdf |archive-url=https://web.archive.org/web/20200226141432/https://pdfs.semanticscholar.org/cd30/5c0e32d229d45a2350db58e9ab79ce48761c.pdf |url-status=dead |archive-date=26 February 2020 }}</ref> Other predators adapted for hunting scorpions include the [[grasshopper mouse]] and [[desert long-eared bat]], which are also immune to their venom.<ref>{{cite journal |last1=Thompson |first1=Benjamin |title=The Grasshopper Mouse and Bark Scorpion: Evolutionary Biology Meets Pain Modulation and Selective Receptor Inactivation |journal=The Journal of Undergraduate Neuroscience Education |date=June 2018 |volume=16 |issue=2 |pages=R51–R53 |pmid=30057511 |pmc=6057761 }}</ref><ref name="Predator of Scorpions"/> In one study, 70% of the latter's droppings contained scorpion fragments.<ref name="Predator of Scorpions">{{Cite journal | last1=Holderied | first1=M. | last2=Korine | first2=C. | last3=Moritz | first3=T. | title=Hemprich's Long-eared Bat (''Otonycteris hemprichii'') as a Predator of Scorpions: Whispering Echolocation, Passive Gleaning and Prey Selection | journal=Journal of Comparative Physiology A | volume=197 | issue=5 | pages=425–433 | year=2010 | doi=10.1007/s00359-010-0608-3| pmid=21086132 | s2cid=25692517 }}</ref> Scorpions host parasites including [[mite]]s, [[scuttle flies]], [[nematode]]s and some bacteria. The [[immune system]] of scorpions gives them resistance to infection by many types of bacteria.{{sfn|Stockmann|2015|pp=38, 45}}

When threatened, a scorpion raises its claws and tail in a defensive posture. Some species [[stridulate]] to warn off predators by rubbing certain hairs, the stinger or the claws.{{sfn|Stockmann|2015|pp=36–37}} Certain species have a preference for using either the claws or stinger as defense, depending on the size of the appendages.<ref>{{cite journal |last1=van der Meijden |first1=A. |last2=Coelho |first2=P. L. |last3=Sousa |first3=P. |last4=Herrel |first4=A. |year=2013 |title=Choose your Weapon: Defensive Behavior is Associated with Morphology and Performance in Scorpions |journal=PLOS ONE |volume=8 |issue=11 |page=e78955 |doi=10.1371/journal.pone.0078955 |pmid=24236075 |pmc=3827323 |bibcode=2013PLoSO...878955V |doi-access=free }}</ref> A few scorpions, such as ''[[Parabuthus]]'', ''[[Centruroides margaritatus]]'', and ''Hadrurus arizonensis''<!--linked above-->, squirt venom in a narrow jet as far as {{convert|1|m|ft|sp=us}} to warn off potential predators, possibly injuring them in the eyes.{{sfn|Stockmann|Ythier|2010|p=90}} Some ''[[Ananteris]]'' species can [[autotomy|shed parts of their tail]] to escape predators. The parts do not grow back, leaving them unable to sting and defecate, but they can still catch small prey and reproduce for at least eight months afterward.<ref>{{cite journal |last1=Mattoni |first1=C. I. |last2=García-Hernández |first2=S. |last3=Botero-Trujillo |first3=R. |last4=Ochoa |first4=J. A. |last5=Ojanguren-Affilastro |first5=A. A. |last6=Pinto-da-Rocha |first6=R. |last7=Prendini |first7=L. |year=2015 |title=Scorpion Sheds 'Tail' to Escape: Consequences and Implications of Autotomy in Scorpions (Buthidae: ''Ananteris'') |journal=PLOS ONE |volume=10 |issue=1 |page=e0116639 |doi=10.1371/journal.pone.0116639|pmid=25629529 |pmc=4309614 |bibcode=2015PLoSO..1016639M |s2cid=17870490 |doi-access=free }}</ref>

===Diet and feeding===

[[File:Scorpion eating solifugid (Marshal Hedin).jpg|thumb|right<!--left-->|Scorpion feeding on a [[solifugid]] ]]

Scorpions generally prey on insects, particularly [[grasshopper]]s, [[Cricket (insect)|cricket]]s, [[termite]]s, [[beetle]]s and [[wasp]]s. Other prey include spiders, [[solifugid]]s, [[woodlice]] and even small [[vertebrate]]s including lizards, snakes and mammals. Species with large claws may prey on earthworms and mollusks. The majority of species are opportunistic and consume a variety of prey though some may be highly specialized; ''[[Isometroides vescus]]'' specializes on burrowing spiders. Prey size depends on the size of the species. Several scorpion species are [[sit-and-wait predator]]s, which involves them waiting for prey at or near the entrance to their burrow. Others actively seek them out. Scorpions detect their prey with [[mechanoreceptive]] and [[chemoreceptive]] hairs on their bodies and capture them with their claws. Small animals are merely killed with the claws, particularly by large-clawed species. Larger and more aggressive prey is given a sting.{{sfn|Stockmann|2015|pp=35–38}}<ref>{{cite web |last=Murray |first=Melissa |title=Scorpions |publisher=Australian Museum |url=https://australian.museum/learn/animals/spiders/scorpions/#:~:text=Scorpions%20are%20nocturnal%20hunters%2C%20feeding,and%20often%20occupying%20their%20burrows |date=3 December 2020 |access-date=13 December 2020 |archive-date=8 November 2020 |archive-url=https://web.archive.org/web/20201108102328/https://australian.museum/learn/animals/spiders/scorpions/#:~:text=Scorpions%20are%20nocturnal%20hunters%2C%20feeding,and%20often%20occupying%20their%20burrows |url-status=live }}</ref>

Scorpions, like other arachnids, digest their food externally. The chelicerae, which are very sharp, are used to pull small amounts of food off the prey item into a pre-oral cavity below the chelicerae and carapace. The digestive juices from the gut are egested onto the food, and the digested food is then sucked into the gut in liquid form. Any solid indigestible matter (such as [[exoskeleton]] fragments) is trapped by [[seta]]e in the pre-oral cavity and ejected. The sucked-in food is pumped into the midgut by the [[pharynx]], where it is further digested. The waste passes through the hindgut and out of the anus. Scorpions can consume large amounts of food during one meal. They have an efficient food storage organ and a very low [[metabolic rate]], and a relatively inactive lifestyle. This enables some to survive six to twelve months of starvation.{{sfn|Polis|1990|pp=296–298}}

===Mating===

[[File:Dancing scorpions-66970ep.jpg|thumb|right|Male and female scorpion during ''promenade à deux'']]

Most scorpions reproduce sexually, with male and female individuals; species in some genera, such as ''[[Hottentotta]]'' and ''[[Tityus (genus)|Tityus]]'', and the species ''[[Centruroides gracilis]]'', ''[[Liocheles australasiae]]'', and ''[[Ananteris coineaui]]'' have been reported, not necessarily reliably, to reproduce through [[parthenogenesis]], in which unfertilized eggs develop into living [[embryo]]s.<ref name="Lourenço 2008">{{cite journal |last=Lourenço |first=Wilson R. |author-link=Wilson R. Lourenço |title=Parthenogenesis in Scorpions: Some History – New Data |journal=Journal of Venomous Animals and Toxins Including Tropical Diseases |volume=14 |issue=1 |year=2008 |issn=1678-9199 |doi=10.1590/S1678-91992008000100003 |doi-access=free}}</ref> Receptive females produce [[pheromone]]s which are picked up by wandering males using their pectines to comb the substrate. Males begin courtship by moving their bodies back and forth, without moving the legs, a behavior known as juddering. This appears to produce ground vibrations that are picked up by the female.{{sfn|Stockmann|2015|p=47}}

The pair then make contact using their pedipalps, and perform a [[dance]] called the ''promenade à deux'' (French for "a walk for two"). In this dance, the male and female move back and forth while facing each other, as the male searches for a suitable place to deposit his spermatophore. The courtship ritual can involve several other behaviors such as a cheliceral kiss, in which the male and female grasp each other's mouth-parts, ''arbre droit'' ("upright tree") where the partners elevate their posteriors and rub their tails together, and sexual stinging, in which the male stings the female in the chelae or mesosoma to subdue her. The dance can last from a few minutes to several hours.{{sfn|Stockmann|2015|pp=47–50}}{{sfn|Stockmann|Ythier|2010|pp=126–128}}

When the male has located a suitably stable substrate, such as hard ground, agglomerated sand, rock, or tree bark, he deposits the spermatophore and guides the female over it. This allows the spermatophore to enter her genital opercula, which triggers release of the sperm, thus fertilizing the female. A [[mating plug]] then forms in the female to prevent her from mating again before the young are born. The male and female then abruptly separate.{{sfn|Stockmann|2015|pp=49–50}}{{sfn|Stockmann|Ythier|2010|p=129}} [[Sexual cannibalism]] after mating has only been reported anecdotally in scorpions.<ref name="Peretti1999">{{cite journal |last=Peretti |first=A. |title=Sexual Cannibalism in Scorpions: Fact or Fiction? |journal=Biological Journal of the Linnean Society |volume=68 |issue=4 |year=1999 |pages=485–496 |issn=0024-4066 |doi=10.1111/j.1095-8312.1999.tb01184.x |doi-access=free}}</ref>

===Birth and development===

[[File:scorpionwithyoung.JPG|thumb|''[[Compsobuthus werneri]]'' female with [[Offspring|young]] ]]

[[Gestation]] in scorpions can last for over a year in some species.{{sfn|Polis|1990|p=161}} They have two types of [[embryonic development]]; apoikogenic and katoikogenic. In the apoikogenic system, which is mainly found in the Buthidae, embryos develop in yolk-rich eggs inside [[Ovarian follicle|follicles]]. The katoikogenic system is documented in Hemiscorpiidae, Scorpionidae and Diplocentridae, and involves the embryos developing in a [[diverticulum]] which has a teat-like structure for them to feed through.<ref>{{cite journal |last=Warburg |first=M. R. |year=2010 |title=Reproductive System of Female Scorpion: A Partial Review |journal=The Anatomical Record |volume=293 |issue=10 |pages=1738–1754 |doi=10.1002/ar.21219 |pmid=20687160 |s2cid=25391120 |doi-access=free}}</ref> Unlike the majority of arachnids, which are [[oviparous]], hatching from eggs, scorpions seem to be universally [[viviparous]], with live births.<ref name="Warburg">{{cite journal |last1=Warburg |first1=Michael R. |title=Pre- and Post-parturial Aspects of Scorpion Reproduction: a Review |journal=European Journal of Entomology |date=5 April 2012 |volume=109 |issue=2 |pages=139–146 |doi=10.14411/eje.2012.018 |doi-access=free }}</ref> They are unusual among terrestrial arthropods in the amount of care a female gives to her offspring.{{sfn|Polis|1990|p=6}} The size of a brood varies by species, from 3 to over 100.<ref name="Scharff"/> The body size of scorpions is not correlated either with brood size or with life cycle length.<ref>{{cite journal |last=Monge-Nájera |first=J. |year=2019 |title=Scorpion Body Size, Litter Characteristics, and Duration of the Life Cycle (Scorpiones) |journal=Cuadernos de Investigación UNED |volume=11 |issue=2 |pages=101–104}}</ref>

Before giving birth, the female elevates the front of her body and positions her pedipalps and front legs under her to catch the young ("birth basket"). The young emerge one by one from the genital opercula, expel the embryonic membrane, if any, and are placed on the mother's back where they remain until they have gone through at least one [[ecdysis|molt]]. The period before the first molt is called the pro-juvenile stage; the young are unable to feed or sting, but have [[Sucker (zoology)|suckers]] on their tarsi, used to hold on to their mother. This period lasts 5 to 25 days, depending on the species. The brood molt for the first time simultaneously in a process that lasts 6 to 8 hours, marking the beginning of the juvenile stage.<ref name="Scharff">{{cite book |last=Lourenço |first=Wilson R. |author-link=Wilson R. Lourenço |title=European Arachnology |chapter=Reproduction in Scorpions, with Special Reference to Parthenogenesis |year=2000 |editor1-first=S. |editor1-last=Toft |editor2-first=N. |editor2-last=Scharff |publisher=Aarhus University Press |isbn=978-877934-0015 |pages=74–76 |chapter-url=http://www.european-arachnology.org/wdp/wp-content/uploads/2015/08/071-085_Lourenco.pdf |access-date=14 December 2020 |archive-date=31 May 2021 |archive-url=https://web.archive.org/web/20210531031223/http://www.european-arachnology.org/wdp/wp-content/uploads/2015/08/071-085_Lourenco.pdf |url-status=live }}</ref>

Juvenile stages or [[instar]]s generally resemble smaller versions of adults, with fully developed pincers, hairs and stingers. They are still soft and lack pigments, and thus continue to ride on their mother's back for protection. They become harder and more pigmented over the next couple of days. They may leave their mother temporarily, returning when they sense potential danger. Once the exoskeleton is fully hardened, the young can hunt prey on their own and may soon leave their mother.{{sfn|Stockmann|2015|p=54}} A scorpion may molt six times on average before reaching maturity, which may not occur until it is 6 to 83 months old, depending on the species. Some species may live up to 25 years.{{sfn|Polis|1990|p=161}}

===Fluorescence===

{{multiple image|image1=Sorpion Under Blacklight edit.jpg|caption1=This black [[emperor scorpion]] (''Pandinus imperator'') [[fluoresce]]s light blue.|width1=200|image2=Scorpion with babies in UV.jpg|caption2=The mother glows bright teal, the young a dull grey.|width2=113}}

Scorpions glow a vibrant blue-green when exposed to certain wavelengths of [[ultraviolet]] light, such as that produced by a [[black light]], due to [[fluorescent]] chemicals such as [[beta-carboline]] in the cuticle. Accordingly, a hand-held ultraviolet lamp has long been a standard tool for nocturnal field surveys of these animals. Fluorescence occurs as a result of [[sclerotization]] and increases in intensity with each successive instar.<ref name="Stachel 1999 531–539">{{cite journal |first1=Shawn J. |last1=Stachel |first2=Scott A. |last2=Stockwell |first3=David L. |last3=Van Vranken |date=August 1999 |title=The Fluorescence of Scorpions and Cataractogenesis |journal=Chemistry & Biology |volume=6 |pages=531–539 |doi=10.1016/S1074-5521(99)80085-4 |pmid=10421760 |issue=8 |doi-access=free }}</ref> This fluorescence may have an active role in the scorpion's ability to detect light.<ref>{{cite journal |last1=Gaffinr |first1=Douglas D. |last2=Bumm |first2=Lloyd A. |last3=Taylor |first3=Matthew S. |last4=Popokina |first4=Nataliya V. |last5=Mann |first5=Shivani |year=2012 |title=Scorpion Fluorescence and Reaction to Light |journal=[[Animal Behaviour (journal)|Animal Behaviour]] |issue=2 |doi=10.1016/j.anbehav.2011.11.014 |volume=83 |pages=429–436 |s2cid=17041988 |url=https://zenodo.org/record/895450 |access-date=18 May 2018 |archive-date=6 November 2020 |archive-url=https://web.archive.org/web/20201106153700/https://zenodo.org/record/895450 |url-status=live }}</ref>

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