Sports bra and Gila monster: Difference between pages

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{{Taxobox
[[Image:Sports bra.jpg|thumb|right|Woman in a sports bra]]
| name = Gila monster
'''Sports bra''' is a [[Brassiere|bra]] that provides firm support for the [[breast]]s. It is intended for wear during vigorous exercise that might cause the breasts to move uncomfortably, preventing [[discomfort]] and [[embarrassment]] during exercise. Sports bras are sturdier than regular bras and offer greater support for the chest, thus increasing comfort and reducing the chance of damage to the [[ligament]]s of the chest during high-impact exercises, such as jogging.
| status = NT
| status_system = iucn3.1
| image = Gila monster2.JPG
| image_width = 250px
| regnum = [[Animal]]ia
| phylum = [[Chordate|Chordata]]
| classis = [[Reptile|Reptilia]]
| ordo = [[Squamata]]
| familia = [[Helodermatidae]]
| genus = ''[[Heloderma]]''
| species = '''''H. suspectum'''''
| binomial = ''Heloderma suspectum''
| binomial_authority = [[Edward Drinker Cope|Cope]], 1869
}}
The '''Gila monster''' ({{pronEng|ˈhiːlə}}, HEE-la), ''Heloderma suspectum'', is a species of [[venom (poison)|venomous]] [[lizard]] native to the [[southwestern United States]] and northern [[Mexico]] (but not Baja California). A heavy, slow moving lizard, up to {{convert|60|cm|ft}} long, the Gila monster is the only venomous lizard native to the United States, and one of only two known species of venomous lizard in North America, the other being its close relative the [[Beaded Lizard]] (''H. horridum'').<ref name="fry">{{cite journal|last=Fry|first = Bryan G.|coauthors=et al.|year=2006|month=February|title=Early evolution of the venom system in lizards and snakes.|journal=Nature|volume = 439|issue=7076|pages=584–588|doi=10.1038/nature04328|url=http://scholar.google.com/scholar?hl=en&q=%22Early%20evolution%20of%20the%20venom%20system%20in%20lizards%20and%20snakes%22%20Letters%20Nature%2010.1038&oe=UTF-8&um=1&ie=UTF-8&sa=N&tab=ws|accessdate=2008-05-14}}</ref> Though the Gila monster is venomous, its sluggish nature means that it represents little threat to humans. However, it has earned a fearsome reputation, and is often killed by hikers and homeowners, despite the fact that it is protected by state law in [[Arizona]] and [[Nevada]].<ref name="ITIS">{{ITIS|ID=174113|taxon=''Heloderma suspectum''|year=2008|date=19 May}}</ref><ref name="iucn">{{cite web|url=http://www.iucnredlist.org/search/details.php/9865/all |title=2007 IUCN Red List &ndash; Search |publisher=Iucnredlist.org |date= |accessdate=2008-09-19}}</ref>


==Taxonomy and etymology==
==Design==
There are two subspecies of Gila monster: the Reticulate Gila Monster (''H. suspectum suspectum'') and the Banded Gila Monster (''H. suspectum cinctum'').<ref name="ITIS"/> The reticulate Gila monster lives in the southern region of the Gila monster's range, while the banded Gila monster is a northern subspecies occurring primarily in the [[Mojave Desert]]. The reticulate Gila monster tends to have its lighter markings broken up by dark scales, giving it a [[wiktionary:reticulate|reticulated]] pattern, while the banded Gila monster generally have more unbroken bands of lighter scales.<ref name="Stebbins"/><ref name="mattison"/>
A sports bra is basically a [[tank top]] with the bottom half cut off. The first sports bra dates from [[1977]]. [[Hinda Miller]] and Lisa Landahl cut up a pair of jockstraps and sewed them together into a bra; it was marketed as the Jogbra.<ref name="miller">{{Cite web |last=Miller |first=Hinda |url=http://www.msmoney.com/mm/success_stories/jogbra_beyond.htm |title=Jogbra and Beyond |publisher=Ms. Money |accessdate=2007-10-26}}</ref> Other designs use gel and water pads, silver fibres, and air bags. A stitchless bra was made by [[Wacoal]], molded, compressed, and shaped. Other bras are knitted in circular patterns, giving varying stretch and support.<ref name="casselman">{{cite journal |last=Casselman |first=Anne |year=2005 |month=November |title=The Physics of Bras |journal=[[Discover (magazine)|Discover]] |volume=26 |issue=11 |pages= |id= |url=http://www.discover.com/issues/nov-05/departments/physics-of-bras/ }}</ref> A common basis is a stretchable, absorbent fabric such as [[Lycra]], and may be designed to draw [[perspiration]] away from the skin to reduce irritation. Sports bras can be classified into either encapsulation brassieres (with molded cups), or compression brassieres that restrict movement by flattening the breasts. Encapsulation is generally better for reducing discomfort; some women prefer compression designs for modesty.


The Gila monster has one close living relative, the Beaded Lizard (''H. horridum''), as well as many extinct relatives in the [[Helodermatidae]] whose evolutionary history may be traced back to the [[Cretaceous]] period. The genus ''Heloderma'' has existed since the [[Miocene]], when ''H. texana'' lived, and fragments of [[osteoderm]]s from the Gila monster have been found in late [[Pleistocene]] (8000-10,000 years ago) deposits near [[Las Vegas, Nevada]]. Because the Helodermatids have remained relatively unchanged morphologically, they are occasionally regarded as [[living fossil]]s.<ref name="varanoid"/> Although the Gila monster appears closely related to the [[monitor lizard]]s (varanids) of Africa, Asia and Australia, the wide geographical separation and unique features not found in the varanids indicates that the Gila monster is better placed in a separate family.<ref name="mattison"/>
A number of women, particularly those with large breasts, find sports bras helpful for easing pain and discomfort or if embarrassment prevents them from participating. Some sports bras are meant to be worn as outerwear, such as for jogging. Most bra research has concentrated on sports bras, where discomfort is directly related to the degree of nipple movement. While sports bras are more effective in this regard than standard bras, they also vary considerably in their effectiveness.


The name ''Gila'' refers to the [[Gila River]] Basin in [[Arizona]], where they were once plentiful.<ref>{{cite web |url=http://www.etymonline.com/index.php?search=gila+monster&searchmode=none |title=Online Etymology Dictionary |format= |work= |accessdate=2008-06-10}}</ref> ''Heloderma'' means "studded skin", from the [[Ancient Greek]] words ''Helos'' &mdash; the head of a nail or stud &mdash; and ''derma'', or skin. ''Suspectum'' comes from the describer, paleontologist [[Edward Drinker Cope]], who suspected that the lizard might be venomous due to the grooves in the teeth.<ref name="varanoid">{{cite book |author=King, Ruth Allen; Pianka, Eric R.; King, Dennis |title=Varanoid Lizards of the World |publisher=Indiana University Press |location=Bloogila monsters fuck pussy real hard|year=2004 |pages= |isbn=0-253-34366-6 |oclc= |doi= |accessdate=}}</ref>
==Exercise discomfort==
About 50 percent of women report some pain or discomfort in their breasts during exercise. This varies considerably in intensity and may depend on what they are wearing. In an Australian study 3 women (17-21, cup sizes B and C) were photographed exercising bare breasted, with two models of a bra, and with a particular sports bra. As expected, breast motion was reduced by bras, and the sports bra was the most effective. The women reported less discomfort with bras and especially with the sports bra. However not all sports bras are created equally and should be properly fitted. <ref>{{cite journal |last=Mason |first=BR |coauthors=Page, KA; Fallon, K |year=1999 |month=June |title=An analysis of movement and discomfort of the female breast during exercise and the effects of breast support in three cases |journal=J Sci Med Sport |volume=2 |issue=2 |pages=134–44 |pmid=10476977 |doi=10.1016/S1440-2440(99)80193-5 }}</ref> A [[2007]] study found that breasts move in three planes of motion during exercise. This study concluded that encapsulation bras are more effective than compression bras at reducing total breast motion during exercise because encapsulation bras reduce motion in two of the three planes, while compression bras reduce motion in only one plane<ref>[http://www.sciencedaily.com/releases/2007/09/070915124901.htm University of Portsmouth (2007, September 23). Bouncing Breasts Spark New Bra Challenge.]</ref>


==Description==
Although some women athletes are concerned that a sports bra may interfere with breathing, and increased pressure on the rib cage has been demonstrated, no significant effect on breathing can be shown.<ref>
[[Image:Gila fg01.jpg|thumb|right|Closeup of a Helodermatid's skin, comprised of beadlike scales.]]
{{cite journal |last=Bowles |first=KA |authorlink= |coauthors=Steele, JR; Chaunchaiyakul, R |year=2005 |month=Sep |title=Do current sports brassiere designs impede respiratory function? |journal=Med Sci Sports Exerc. |volume=37 |issue=9 |pages=1633–40 |pmid = 16177619 |doi=10.1249/01.mss.0000177590.75686.28 }}</ref>
''H. suspectum'' is a bulky, sausage-shaped lizard with a length of {{convert|30|cm|ft}} to {{convert|60|cm|ft}} and a weight of {{convert|1.3|kg|lb}} to {{convert|2.25|kg|lb}}.<ref name="seaworld">{{cite web |url=http://www.seaworld.org/animal-info/Animal-Bytes/animalia/eumetazoa/coelomates/deuterostomes/chordata/craniata/reptilia/squamata/gila-monster.htm |title=Animal Bytes - Gila Monster |publisher=[[Sea World]] |format= |work= |accessdate=2008-06-09}}</ref> Although smaller than the Beaded Lizard, which can grow to be a {{convert|1|m|ft}} long,<ref name="greene">{{cite book |author=Greene, Harry L.; Pianka, Eric R.; Vitt, Laurie J. |title=Lizards: Windows to the Evolution of Diversity |publisher=University of California Press |location=Berkeley |year=2003 |pages= |isbn=0-520-23401-4 |oclc= |doi= |accessdate=}}</ref> the Gila monster is the largest lizard in the United States.<ref name="seaworld"/> It has a thick tail that is used to store fat, which it can live off of for months, or for years according to several anecdotes. Its tail is proportionately longer than that of the Beaded Lizard, a trait used to differentiate between the two. Unlike many other lizards, a Gila monster's tail does not [[autotomy|autotomize]] and cannot grow back if broken. The Gila monster also possesses large forefeet and sharp claws, ideal for digging, as well as a thick black tongue, used to smell with the help of a [[Jacobson's organ]].<ref name="greene"/>

The Gila monster's scales have the appearance of black, pink, orange, or yellow beads, laid down in intricate patterns. These beads are small bony plates that form [[scale (zoology)|scales]], and are known as [[osteoderms]].<ref name="Audubon">{{cite book | last = Bebler | first = John L. | last2 = King | first2 = F. Wayne | title = The Audubon Society Field Guide to Reptiles and Amphibians of North America | publisher = Alfred A. Knopf |Location= New York | pages = 581 | year= 1979 | isbn = 0394508246}}</ref> The colors of its osteoderms are more vivid than those of its close relative, the Beaded Lizard. The scales on the belly are rectangular rather than rounded. It was the beaded skin of the Gila monster that caught the attention of Native Americans, the designs of which are recreated in Native American art and basketry.<ref name="netherton">{{cite book |author=Netherton, John; Badger, David P. |title=Lizards: A Natural History of Some Uncommon Creatures, Extraordinary Chameleons, Iguanas, Geckos, and More |publisher=Voyageur Press |location=Stillwater, MN |year=2002 |pages= |isbn=0-7603-2579-0 |oclc= |doi= |accessdate=}}</ref> The scales are most vivid when the Gila monster is young; as it ages, the colors become paler and more reticulated.<ref name="greene"/> The Gila monster [[moult|shed]]s its skin in small patches, such that they always seem to be in the process of shedding. Complete [[moult|molting]] is thought to occur once per year.<ref>{{cite journal|last=Bogert|first=C.M.|coauthors=R.M. del Campo|year=1956|title=The Gila monster and its allies: The relationships, habits, and behavior of the lizards of the family Helodermatidae|journal=Bulletin of the American Museum of Natural History|volume=109|pages=1–238}}</ref>

==Distribution and habitat==
[[Image:Gila Monster head.jpg|thumb|right|A Gila monster's head. The bead-like scales can be observed, as well as the strong forelegs and claws suitable for digging.]]
The Gila monster is found in the [[Southwestern United States]] and Mexico, a range entailing [[Sonora]], [[Sinaloa]], [[Arizona]], parts of [[California]], [[Nevada]], [[Utah]], and [[New Mexico]] (but not Baja California). They inhabit [[scrubland]], succulent desert, and oak woodland, seeking shelter in burrows, thickets, and under rocks in locations with ready access to moisture.<ref name="Stebbins">{{cite book |last= Stebbins|first= Robert|title= Western Reptiles and Amphibians|year= 2003||publisher= Houghton Mifflin |pages = 338-339, 537|location= [[New York]]|isbn= 0395982723}}</ref> In fact, Gila monsters seem to like water, and can be observed immersing themselves in puddles of water after a summer rain.<ref name="cavendish">{{cite book |author= |title=Endangered Wildlife and Plants of the World |publisher=[[Marshall Cavendish]] |location=London |year=2001 |pages=629-630 |isbn=0-7614-7199-5 |oclc= |doi= |accessdate=}}</ref> They avoid living in open areas such as flats and farmland.<ref name="nzp">{{cite web |url=http://nationalzoo.si.edu/Animals/ReptilesAmphibians/Facts/FactSheets/Gilamonster.cfm |title=Gila Monster Fact Sheet |publisher=[[Smithsonian National Zoological Park]] |format= |work= |accessdate=2008-06-06}}</ref>

==Ecology==
It is estimated that the Gila monster spends 95% of its time underground in mammal burrows or rocky shelters. It is active in the morning during the dry season (spring and early summer); later in the summer it may be active on warm nights or after a [[thunderstorm]]. On the surface, it maintains a body temperature of about {{convert|30|C|F}}.<ref name="greene"/>

===Diet===
The Gila monster feeds primarily on bird and reptile [[Egg (biology)|egg]]s, and occasionally upon small birds, mammals, frogs, lizards, insects, and [[carrion]].<ref name="animal">{{cite book |author=Wilson, Don W.; Burnie, David |title=Animal |publisher=DK |location=London |year=2001 |pages=419 |isbn=0-7894-7764-5 |oclc= |doi= |accessdate=}}</ref> The Gila monster eats infrequently (only five to ten times a year in the wild),<ref>{{cite web |url=http://www2.philadelphiazoo.org/zoo/Meet-Our-Animals/Reptiles/Lizards-and-Snakes/Gila-Monster.htm |title=Meet Our Animals: Gila monster |publisher=[[Philadelphia Zoo]] |format= |work= |accessdate=2008-09-20}}</ref> but when it does feed, it may eat up to one-third of its body mass.<ref>{{cite journal |author=Christel CM, DeNardo DF, Secor SM |title=Metabolic and digestive response to food ingestion in a binge-feeding lizard, the Gila monster (Heloderma suspectum) |journal=J. Exp. Biol. |volume=210 |issue=Pt 19 |pages=3430–9 |year=2007 |month=October |pmid=17872997 |doi=10.1242/jeb.004820 |url= |accessdate=}}</ref> It uses its extremely acute sense of smell to locate prey, especially eggs. Its sense of smell is so keen that it can locate and dig up chicken eggs buried {{convert|15|cm|in}} deep and accurately follow a trail made by rolling an egg.<ref name="mattison"/>

Prey may be crushed to death if large or eaten alive if small, swallowed head-first and helped down by muscular contractions and neck flexing. Unusually, after food has been swallowed, the Gila monster immediately resumes tongue flicking and search behavior, probably as a result of a history of finding clumped prey such as eggs and babies in nests.<ref name="greene"/> Gila monsters are able to climb trees and [[cactus|cacti]] in search of eggs.<ref name="netherton"/>

===Venom===
{{rquote|right|I have never been called to attend a case of Gila monster bite, and I don’t want to be. I think a man who is fool enough to get bitten by a Gila monster ought to die. The creature is so sluggish and slow of movement that the victim of its bite is compelled to help largely in order to get bitten.|Dr. Ward, ''Arizona Graphic'', September 23, 1899}}

Venom is produced in modified [[salivary glands]] in the Gila monster's lower jaw, unlike snakes, whose venom is produced in the upper jaw.<ref name="animal"/> The Gila monster lacks the musculature to forcibly inject the venom; instead, the venom is propelled from the gland to the tooth by chewing. [[Capillary action]] brings the venom out of the tooth and into the victim.<ref name="varanoid"/> The teeth are loosely anchored, which allows them to be broken off and replaced throughout life. Gila monsters have also been observed to flip over while biting the victim, presumably to aid the flow of the venom into the wound. Because the Gila monster's prey consists mainly of eggs, small animals, and otherwise "helpless" prey, it is thought that the Gila monster's venom evolved for defensive rather than for hunting use. A defensive use would also explain the Gila monster's bright warning coloration.<ref name="mattison">{{cite book |author=Mattison, Chris |title=Lizards of the World |publisher=Blandford |location=London |year=1998 |pages= |isbn=0-7137-2357-2 |oclc= |doi= |accessdate=}}</ref>

[[Image:Reticulate Gila Monster.jpg|thumb|left|A reticulate Gila monster (''Heloderma suspectum suspectum'')]]
Although the venom is a [[neurotoxin]] as toxic as that of a [[Western diamondback rattlesnake]], ''H. suspectum'' produces only small amounts.<ref name="nzp"/> The Gila monster's bite is normally not fatal to adult humans (there are no confirmed reports of fatalities), but it can bite quickly and hold on tenaciously and painfully.<ref name="greene"/> Symptoms of the bite include excruciating [[pain]], [[edema]], and weakness associated with a rapid drop in [[blood pressure]]. More than a dozen [[peptide]]s and [[protein]]s have been isolated from the Gila monster's venom, including [[hyaluronidase]], [[serotonin]], [[phospholipase]] A<sub>2</sub>, and several [[kallikrein]]-like [[glycoprotein]]s responsible for the pain and edema caused by a bite. Four potentially lethal toxins have also been isolated from the Gila monster's venom, including horridum venom, which causes [[hemorrhage]] in internal organs and bulging of the eyes, and helothermine, which causes [[lethargy]], partial [[paralysis]] of the limbs, and [[hypothermia]] in [[rat]]s. However, the constituents most focused on are the bioactive peptides, including helodermin, helospectin, exendin-3, and exendin-4.<ref>{{cite journal |author=Aird SD |title=Nucleoside composition of Heloderma venoms |journal=Comp. Biochem. Physiol. B, Biochem. Mol. Biol. |volume=150 |issue=2 |pages=183–6 |year=2008 |month=June |pmid=18430599 |doi=10.1016/j.cbpb.2008.02.012 |url=}}</ref> Most are similar in form to [[vasoactive intestinal peptide]] (VIP), which relaxes [[smooth muscle]] and regulates [[water]] and [[electrolyte]] secretion between the [[small intestine|small]] and [[large intestine]]s. These bioactive peptides are able to bind to VIP receptors in many different human tissues. One of these, helodermin, has been shown to inhibit the growth of [[lung cancer]].<ref name="varanoid"/><ref>{{cite journal |author=Maruno K, Said SI |title=Small-cell lung carcinoma: inhibition of proliferation by vasoactive intestinal peptide and helodermin and enhancement of inhibition by anti-bombesin antibody |journal=Life Sci. |volume=52 |issue=24 |pages=PL267–71 |year=1993 |pmid=8389407 |doi= |url=}}</ref>

====Drug research====
{{wikinews|New drug from lizard's saliva}}
In 2005 the U.S. [[Food and Drug Administration]] approved the drug [[exenatide]] for the management of [[Diabetes mellitus type 2|type 2 diabetes]]. It is a synthetic version of a protein, exendin-4, derived from the Gila monster's saliva.<ref name="Baylor">{{cite journal|last=Bond|first=Aaron | title=Exenatide (Byetta) as a novel treatment option for type 2 diabetes mellitus|journal=Baylor University Medical Center Proceedings|volume=19|issue=3 | pages=281–4| year=2006|month=July|pmid=17252050}}</ref> In a three-year study with people with type 2 diabetes, exenatide led to healthy sustained [[glucose]] levels and progressive weight loss. The effectiveness is due to the fact that the lizard hormone is about 50 percent identical to [[glucagon-like peptide-1]] analog (GLP-1), a hormone in the human digestive tract, that increases the production of insulin when blood sugar levels are high. The lizard hormone remains effective much longer than the human hormone, helping diabetics keep their blood sugar levels from getting too high. Exenatide also slows the emptying of the stomach and causes a decrease in appetite, contributing to weight loss.<ref name="drug">{{cite news|title=Drug Derived From Gila Monster Saliva Helps Diabetics Control Glucose, Lose Weight|publisher=Science Daily|url=http://www.sciencedaily.com/releases/2007/07/070709175815.htm|date=2007-07-12}}</ref>

===Life history===
[[Image:gila.monster.arp.jpg|thumb|right|Gila monster at the [[Bristol Zoo]].]]
The Gila monster emerges from [[hibernation]] in the months of January or February and mates in May and June.<ref name="animal"/> The male initiates courtship by flicking his tongue to search for the female's scent. If the female rejects his advances she will bite him and crawl away. When successful, [[copulation]] has been observed to last from 15 minutes to as long as 2.5 hours. The female will lay eggs in July or August, burying them in sand {{convert|12.7|cm|in}} below the surface. The clutch consists of two to twelve eggs, with five being the average clutch.<ref name="Stebbins"/> The process of [[incubation]] lasts nine months as the hatchlings emerge during the months of April through June the following year.<ref name="Seward">{{cite book |author=Seward, Mark|title=Dr. Mark Seward's Gila monster Propagation: How To Breed Gila monsters in Captivity |publisher=Natural Selections Publishing |year=2002 |pages=80 |isbn=0970139500 }}</ref> The hatchlings are about {{convert|16|cm|in}} long, and are able to bite and inject venom upon hatching. The juveniles typically have larger bands of pink scales than adults, although the Banded Gila Monster (''H. s. cinctum'') has a tendency to retain the band pattern. ''H. suspectum'' sexually matures at 3-5 years. After egg-laying, adult Gila monsters gradually spend less time on the surface to avoid the hottest part of the summer (although they may be active in the evening), eventually starting their [[hibernation]] around November.<ref name="mattison"/>

Little is known about the social behavior of ''H. suspectum'', but they have been observed engaging in male-male combat, in which the dominant male lies on top of the subordinate one and pins it with its front and hind limbs. Both lizards arch their bodies, pushing against each other, and twisting around in an effort to gain the dominant position. A wrestling match ends when the pressure exerted forces them to separate, although bouts may be repeated over a continuous amount of time. These bouts are typically observed just before the mating season. It is thought that those with greater strength and endurance win more often and enjoy greater reproductive success.<ref>{{cite journal|last=Beck|first=D.D.|year=1990|title=Ecology and behavior of the Gila monster in southwestern Utah|journal=Journal of Herpetology|volume=24|pages=54–68|doi=10.2307/1564290}}</ref> Although the Gila monster has a low metabolism and one of the lowest lizard sprint speeds, it has one of the highest aerobic scope values (the increase in [[oxygen]] consumption from rest to maximum metabolic exertion) among lizards, allowing them to engage in intense aerobic activity for a sustained period of time. It has also been observed that males have a higher aerobic scope than females, presumably because of [[sexual selection]] for a trait advantageous in prolonged combat.<ref>{{cite journal|last=Beck|first=D.D.|coauthors=M.R. Dohm, J.T. Garland, A. Ramirez-Bautista, and C.H. Lowe|year=1995|title=Locomotor performance and activity energetics of helodermatid lizards|journal=[[Copeia]]|volume=1995|issue=577-585}}</ref> The Gila monster may live up to 20 years in the wild, or 30 in captivity.<ref name="sandiego"/>

==Conservation status==
[[Urban sprawl]], the pet trade, and habitat destruction has affected Gila monster numbers. As a result, Gila monsters are protected by [[Arizona]] and [[Nevada]] state law; it is illegal to "harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect the Gila Monster." In 1952, they became the first venomous animal to be given legal protection.<ref name="cavendish"/><ref name="scz">{{cite web |url=http://www.scz.org/animals/g/gila.html |title=Gila Monster - Heloderma suspectum |publisher=[[Sedgwick County Zoo]] |format= |work= |accessdate=2008-06-09}}</ref><ref>{{cite web |author=Brennan, Thomas C. |url=http://www.reptilesofaz.com/Lizards-Subpages/h-h-suspectum.html |title=Reptiles of Arizona - Gila Monster (Heloderma suspectum) |format= |work= |accessdate=2008-06-10}}</ref> Gila monsters are listed as [[Near Threatened]] by the [[IUCN]].<ref name="iucn"/> The [[San Diego Zoo]] was the first zoo to successfully breed Gila Monsters in captivity, doing so in 1963.<ref name="sandiego">{{cite web |url=http://www.sandiegozoo.org/animalbytes/t-gila_monster.html |title=San Diego Zoo's Animal Bytes: Gila Monster |publisher=[[San Diego Zoo]]|format= |work= |accessdate=2008-05-19}}</ref>

===Relation with humans===
Though the Gila monster is venomous, its laggard movement means that it poses little threat to humans. However, it has earned a fearsome reputation, and is often killed. Among Native American tribes, the Gila monster had a mixed standing. The [[Apache]] believed that its breath could kill a man, and the [[Tohono O'Odham]] and the [[Pima]] believed that it possessed a spiritual power that could cause sickness. In contrast, the [[Seri]] and the [[Yaquai]] believed that the Gila monster's hide had healing properties.<ref name="nzp"/> The Gila monster has even starred as a monster in a [[B movie]], ''[[The Giant Gila Monster]]''. Myths that the animal's breath is toxic enough to kill humans, that it can spit venom, or leap several feet in the air to attack are all false.<ref name="sandiego"/> Another myth held that the Gila monster did not have an [[anus]] and therefore expelled waste from its mouth, the source of its venom and "fetid breath".<ref name="greene"/>


==References==
==References==
{{reflist}}
{{Reflist|2}}
{{reflink|2}}


==Further reading==
{{lingerie}}
{{Wikispecies|Heloderma suspectum}}
{{commons|Heloderma suspectum}}
*{{cite book |author=Beck, Daniel D. |title=Biology of Gila Monsters and Beaded Lizards |publisher=University of California Press |location=Berkeley |year=2005 |pages= |isbn=0-520-24357-9 |oclc= |doi= |accessdate=}}
*{{cite book |last= Capula|first= Massimo|coauthors =Behler|title= Simon & Schuster's Guide to Reptiles and Amphibians of the World |year= 1989||publisher= [[Simon & Schuster]] |location= [[New York]]|isbn= 0671690981}}
*{{cite book |author=Carmony, Neil B.; Brown, David |title=Gila Monster: Facts and Folklore of America's Aztec Lizard |publisher=High-Lonesome Books |location=Silver City, NM |year=1991 |pages= |isbn=0-944383-18-1 |oclc= |doi= |accessdate=}}
*{{cite book | last = Cogger | first = Harold |authorlink = Harold Cogger | last2 = Zweifel | first2 = Richard | title = Reptiles & Amphibians | publisher = Weldon Owen | location = [[Sydney, Australia]] |year = 1992 | isbn = 0831727861}}
*{{cite book | last =Ditmars | first =Raymond L | authorlink =Raymond Ditmars | title = Reptiles of the World: The Crocodilians, Lizards, Snakes, Turtles and Tortoises of the Eastern and Western Hemispheres | publisher =Macmillian | year =1933 | location =[[New York]] | pages =321}}
*{{cite book |last= Freiberg|first= Dr. Marcos|last2= Walls|first2=Jerry |title= The World of Venomous Animals|year= 1984
|publisher= TFH Publications|location=[[New Jersey]] |isbn= 0876665679}}
*{{cite book |author=Roever, J. M.; Hiser, Iona Seibert |title=The Gila Monster |publisher=Steck-Vaughn Co |location=Austin, Tex |year=1972 |pages= |isbn=0-8114-7739-8 |oclc= |doi= |accessdate=}}


{{Varanoidea}}
[[Category:Brassieres]]
[[Category:Sports clothing]]


[[Category:1990s fashion]]
[[Category:Helodermas]]
[[Category:Venomous animals]]
[[Category:Fauna of the Sonoran Desert]]
[[Category:Fauna of Mexico]]
[[Category:Reptiles of the United States]]
[[Category:Fauna of the Southwestern United States]]


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[[es:Heloderma suspectum]]
[[fr:Monstre de Gila]]
[[it:Heloderma suspectum]]
[[he:הלודרמה מרירית]]
[[lt:Šiurpusis nuodadantis]]
[[hu:Gila]]
[[nl:Gilamonster]]
[[ja:アメリカドクトカゲ]]
[[no:Gilaøgle]]
[[pl:Heloderma arizońska]]
[[pt:Monstro-de-gila]]
[[simple:Gila monster]]
[[fi:Gilalisko]]
[[th:กิล่ามอนสเตอร์]]

Revision as of 17:59, 10 October 2008

Gila monster
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
Reptilia
Order:
Squamata
Family:
Helodermatidae
Genus:
Heloderma
Species:
H. suspectum
Binomial name
Heloderma suspectum
Cope, 1869

The Gila monster (Template:PronEng, HEE-la), Heloderma suspectum, is a species of venomous lizard native to the southwestern United States and northern Mexico (but not Baja California). A heavy, slow moving lizard, up to 60 centimetres (2.0 ft) long, the Gila monster is the only venomous lizard native to the United States, and one of only two known species of venomous lizard in North America, the other being its close relative the Beaded Lizard (H. horridum).[1] Though the Gila monster is venomous, its sluggish nature means that it represents little threat to humans. However, it has earned a fearsome reputation, and is often killed by hikers and homeowners, despite the fact that it is protected by state law in Arizona and Nevada.[2][3]

Taxonomy and etymology

There are two subspecies of Gila monster: the Reticulate Gila Monster (H. suspectum suspectum) and the Banded Gila Monster (H. suspectum cinctum).[2] The reticulate Gila monster lives in the southern region of the Gila monster's range, while the banded Gila monster is a northern subspecies occurring primarily in the Mojave Desert. The reticulate Gila monster tends to have its lighter markings broken up by dark scales, giving it a reticulated pattern, while the banded Gila monster generally have more unbroken bands of lighter scales.[4][5]

The Gila monster has one close living relative, the Beaded Lizard (H. horridum), as well as many extinct relatives in the Helodermatidae whose evolutionary history may be traced back to the Cretaceous period. The genus Heloderma has existed since the Miocene, when H. texana lived, and fragments of osteoderms from the Gila monster have been found in late Pleistocene (8000-10,000 years ago) deposits near Las Vegas, Nevada. Because the Helodermatids have remained relatively unchanged morphologically, they are occasionally regarded as living fossils.[6] Although the Gila monster appears closely related to the monitor lizards (varanids) of Africa, Asia and Australia, the wide geographical separation and unique features not found in the varanids indicates that the Gila monster is better placed in a separate family.[5]

The name Gila refers to the Gila River Basin in Arizona, where they were once plentiful.[7] Heloderma means "studded skin", from the Ancient Greek words Helos — the head of a nail or stud — and derma, or skin. Suspectum comes from the describer, paleontologist Edward Drinker Cope, who suspected that the lizard might be venomous due to the grooves in the teeth.[6]

Description

Closeup of a Helodermatid's skin, comprised of beadlike scales.

H. suspectum is a bulky, sausage-shaped lizard with a length of 30 centimetres (0.98 ft) to 60 centimetres (2.0 ft) and a weight of 1.3 kilograms (2.9 lb) to 2.25 kilograms (5.0 lb).[8] Although smaller than the Beaded Lizard, which can grow to be a 1 metre (3.3 ft) long,[9] the Gila monster is the largest lizard in the United States.[8] It has a thick tail that is used to store fat, which it can live off of for months, or for years according to several anecdotes. Its tail is proportionately longer than that of the Beaded Lizard, a trait used to differentiate between the two. Unlike many other lizards, a Gila monster's tail does not autotomize and cannot grow back if broken. The Gila monster also possesses large forefeet and sharp claws, ideal for digging, as well as a thick black tongue, used to smell with the help of a Jacobson's organ.[9]

The Gila monster's scales have the appearance of black, pink, orange, or yellow beads, laid down in intricate patterns. These beads are small bony plates that form scales, and are known as osteoderms.[10] The colors of its osteoderms are more vivid than those of its close relative, the Beaded Lizard. The scales on the belly are rectangular rather than rounded. It was the beaded skin of the Gila monster that caught the attention of Native Americans, the designs of which are recreated in Native American art and basketry.[11] The scales are most vivid when the Gila monster is young; as it ages, the colors become paler and more reticulated.[9] The Gila monster sheds its skin in small patches, such that they always seem to be in the process of shedding. Complete molting is thought to occur once per year.[12]

Distribution and habitat

A Gila monster's head. The bead-like scales can be observed, as well as the strong forelegs and claws suitable for digging.

The Gila monster is found in the Southwestern United States and Mexico, a range entailing Sonora, Sinaloa, Arizona, parts of California, Nevada, Utah, and New Mexico (but not Baja California). They inhabit scrubland, succulent desert, and oak woodland, seeking shelter in burrows, thickets, and under rocks in locations with ready access to moisture.[4] In fact, Gila monsters seem to like water, and can be observed immersing themselves in puddles of water after a summer rain.[13] They avoid living in open areas such as flats and farmland.[14]

Ecology

It is estimated that the Gila monster spends 95% of its time underground in mammal burrows or rocky shelters. It is active in the morning during the dry season (spring and early summer); later in the summer it may be active on warm nights or after a thunderstorm. On the surface, it maintains a body temperature of about 30 °C (86 °F).[9]

Diet

The Gila monster feeds primarily on bird and reptile eggs, and occasionally upon small birds, mammals, frogs, lizards, insects, and carrion.[15] The Gila monster eats infrequently (only five to ten times a year in the wild),[16] but when it does feed, it may eat up to one-third of its body mass.[17] It uses its extremely acute sense of smell to locate prey, especially eggs. Its sense of smell is so keen that it can locate and dig up chicken eggs buried 15 centimetres (5.9 in) deep and accurately follow a trail made by rolling an egg.[5]

Prey may be crushed to death if large or eaten alive if small, swallowed head-first and helped down by muscular contractions and neck flexing. Unusually, after food has been swallowed, the Gila monster immediately resumes tongue flicking and search behavior, probably as a result of a history of finding clumped prey such as eggs and babies in nests.[9] Gila monsters are able to climb trees and cacti in search of eggs.[11]

Venom

I have never been called to attend a case of Gila monster bite, and I don’t want to be. I think a man who is fool enough to get bitten by a Gila monster ought to die. The creature is so sluggish and slow of movement that the victim of its bite is compelled to help largely in order to get bitten.

— Dr. Ward, Arizona Graphic, September 23, 1899

Venom is produced in modified salivary glands in the Gila monster's lower jaw, unlike snakes, whose venom is produced in the upper jaw.[15] The Gila monster lacks the musculature to forcibly inject the venom; instead, the venom is propelled from the gland to the tooth by chewing. Capillary action brings the venom out of the tooth and into the victim.[6] The teeth are loosely anchored, which allows them to be broken off and replaced throughout life. Gila monsters have also been observed to flip over while biting the victim, presumably to aid the flow of the venom into the wound. Because the Gila monster's prey consists mainly of eggs, small animals, and otherwise "helpless" prey, it is thought that the Gila monster's venom evolved for defensive rather than for hunting use. A defensive use would also explain the Gila monster's bright warning coloration.[5]

A reticulate Gila monster (Heloderma suspectum suspectum)

Although the venom is a neurotoxin as toxic as that of a Western diamondback rattlesnake, H. suspectum produces only small amounts.[14] The Gila monster's bite is normally not fatal to adult humans (there are no confirmed reports of fatalities), but it can bite quickly and hold on tenaciously and painfully.[9] Symptoms of the bite include excruciating pain, edema, and weakness associated with a rapid drop in blood pressure. More than a dozen peptides and proteins have been isolated from the Gila monster's venom, including hyaluronidase, serotonin, phospholipase A2, and several kallikrein-like glycoproteins responsible for the pain and edema caused by a bite. Four potentially lethal toxins have also been isolated from the Gila monster's venom, including horridum venom, which causes hemorrhage in internal organs and bulging of the eyes, and helothermine, which causes lethargy, partial paralysis of the limbs, and hypothermia in rats. However, the constituents most focused on are the bioactive peptides, including helodermin, helospectin, exendin-3, and exendin-4.[18] Most are similar in form to vasoactive intestinal peptide (VIP), which relaxes smooth muscle and regulates water and electrolyte secretion between the small and large intestines. These bioactive peptides are able to bind to VIP receptors in many different human tissues. One of these, helodermin, has been shown to inhibit the growth of lung cancer.[6][19]

Drug research

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In 2005 the U.S. Food and Drug Administration approved the drug exenatide for the management of type 2 diabetes. It is a synthetic version of a protein, exendin-4, derived from the Gila monster's saliva.[20] In a three-year study with people with type 2 diabetes, exenatide led to healthy sustained glucose levels and progressive weight loss. The effectiveness is due to the fact that the lizard hormone is about 50 percent identical to glucagon-like peptide-1 analog (GLP-1), a hormone in the human digestive tract, that increases the production of insulin when blood sugar levels are high. The lizard hormone remains effective much longer than the human hormone, helping diabetics keep their blood sugar levels from getting too high. Exenatide also slows the emptying of the stomach and causes a decrease in appetite, contributing to weight loss.[21]

Life history

Gila monster at the Bristol Zoo.

The Gila monster emerges from hibernation in the months of January or February and mates in May and June.[15] The male initiates courtship by flicking his tongue to search for the female's scent. If the female rejects his advances she will bite him and crawl away. When successful, copulation has been observed to last from 15 minutes to as long as 2.5 hours. The female will lay eggs in July or August, burying them in sand 12.7 centimetres (5.0 in) below the surface. The clutch consists of two to twelve eggs, with five being the average clutch.[4] The process of incubation lasts nine months as the hatchlings emerge during the months of April through June the following year.[22] The hatchlings are about 16 centimetres (6.3 in) long, and are able to bite and inject venom upon hatching. The juveniles typically have larger bands of pink scales than adults, although the Banded Gila Monster (H. s. cinctum) has a tendency to retain the band pattern. H. suspectum sexually matures at 3-5 years. After egg-laying, adult Gila monsters gradually spend less time on the surface to avoid the hottest part of the summer (although they may be active in the evening), eventually starting their hibernation around November.[5]

Little is known about the social behavior of H. suspectum, but they have been observed engaging in male-male combat, in which the dominant male lies on top of the subordinate one and pins it with its front and hind limbs. Both lizards arch their bodies, pushing against each other, and twisting around in an effort to gain the dominant position. A wrestling match ends when the pressure exerted forces them to separate, although bouts may be repeated over a continuous amount of time. These bouts are typically observed just before the mating season. It is thought that those with greater strength and endurance win more often and enjoy greater reproductive success.[23] Although the Gila monster has a low metabolism and one of the lowest lizard sprint speeds, it has one of the highest aerobic scope values (the increase in oxygen consumption from rest to maximum metabolic exertion) among lizards, allowing them to engage in intense aerobic activity for a sustained period of time. It has also been observed that males have a higher aerobic scope than females, presumably because of sexual selection for a trait advantageous in prolonged combat.[24] The Gila monster may live up to 20 years in the wild, or 30 in captivity.[25]

Conservation status

Urban sprawl, the pet trade, and habitat destruction has affected Gila monster numbers. As a result, Gila monsters are protected by Arizona and Nevada state law; it is illegal to "harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect the Gila Monster." In 1952, they became the first venomous animal to be given legal protection.[13][26][27] Gila monsters are listed as Near Threatened by the IUCN.[3] The San Diego Zoo was the first zoo to successfully breed Gila Monsters in captivity, doing so in 1963.[25]

Relation with humans

Though the Gila monster is venomous, its laggard movement means that it poses little threat to humans. However, it has earned a fearsome reputation, and is often killed. Among Native American tribes, the Gila monster had a mixed standing. The Apache believed that its breath could kill a man, and the Tohono O'Odham and the Pima believed that it possessed a spiritual power that could cause sickness. In contrast, the Seri and the Yaquai believed that the Gila monster's hide had healing properties.[14] The Gila monster has even starred as a monster in a B movie, The Giant Gila Monster. Myths that the animal's breath is toxic enough to kill humans, that it can spit venom, or leap several feet in the air to attack are all false.[25] Another myth held that the Gila monster did not have an anus and therefore expelled waste from its mouth, the source of its venom and "fetid breath".[9]

References

  1. ^ Fry, Bryan G. (2006). "Early evolution of the venom system in lizards and snakes". Nature. 439 (7076): 584–588. doi:10.1038/nature04328. Retrieved 2008-05-14. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)
  2. ^ a b "Heloderma suspectum". Integrated Taxonomic Information System. 19 May. {{cite web}}: Check date values in: |date= and |year= / |date= mismatch (help)
  3. ^ a b "2007 IUCN Red List – Search". Iucnredlist.org. Retrieved 2008-09-19.
  4. ^ a b c Stebbins, Robert (2003). Western Reptiles and Amphibians. New York: Houghton Mifflin. pp. 338–339, 537. ISBN 0395982723. {{cite book}}: Cite has empty unknown parameter: |1= (help)
  5. ^ a b c d e Mattison, Chris (1998). Lizards of the World. London: Blandford. ISBN 0-7137-2357-2.
  6. ^ a b c d King, Ruth Allen; Pianka, Eric R.; King, Dennis (2004). Varanoid Lizards of the World. Bloogila monsters fuck pussy real hard: Indiana University Press. ISBN 0-253-34366-6.{{cite book}}: CS1 maint: multiple names: authors list (link)
  7. ^ "Online Etymology Dictionary". Retrieved 2008-06-10.
  8. ^ a b "Animal Bytes - Gila Monster". Sea World. Retrieved 2008-06-09.
  9. ^ a b c d e f g Greene, Harry L.; Pianka, Eric R.; Vitt, Laurie J. (2003). Lizards: Windows to the Evolution of Diversity. Berkeley: University of California Press. ISBN 0-520-23401-4.{{cite book}}: CS1 maint: multiple names: authors list (link)
  10. ^ Bebler, John L.; King, F. Wayne (1979). The Audubon Society Field Guide to Reptiles and Amphibians of North America. Alfred A. Knopf. p. 581. ISBN 0394508246. {{cite book}}: Unknown parameter |Location= ignored (|location= suggested) (help)
  11. ^ a b Netherton, John; Badger, David P. (2002). Lizards: A Natural History of Some Uncommon Creatures, Extraordinary Chameleons, Iguanas, Geckos, and More. Stillwater, MN: Voyageur Press. ISBN 0-7603-2579-0.{{cite book}}: CS1 maint: multiple names: authors list (link)
  12. ^ Bogert, C.M. (1956). "The Gila monster and its allies: The relationships, habits, and behavior of the lizards of the family Helodermatidae". Bulletin of the American Museum of Natural History. 109: 1–238. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  13. ^ a b Endangered Wildlife and Plants of the World. London: Marshall Cavendish. 2001. pp. 629–630. ISBN 0-7614-7199-5.
  14. ^ a b c "Gila Monster Fact Sheet". Smithsonian National Zoological Park. Retrieved 2008-06-06.
  15. ^ a b c Wilson, Don W.; Burnie, David (2001). Animal. London: DK. p. 419. ISBN 0-7894-7764-5.{{cite book}}: CS1 maint: multiple names: authors list (link)
  16. ^ "Meet Our Animals: Gila monster". Philadelphia Zoo. Retrieved 2008-09-20.
  17. ^ Christel CM, DeNardo DF, Secor SM (2007). "Metabolic and digestive response to food ingestion in a binge-feeding lizard, the Gila monster (Heloderma suspectum)". J. Exp. Biol. 210 (Pt 19): 3430–9. doi:10.1242/jeb.004820. PMID 17872997. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  18. ^ Aird SD (2008). "Nucleoside composition of Heloderma venoms". Comp. Biochem. Physiol. B, Biochem. Mol. Biol. 150 (2): 183–6. doi:10.1016/j.cbpb.2008.02.012. PMID 18430599. {{cite journal}}: Unknown parameter |month= ignored (help)
  19. ^ Maruno K, Said SI (1993). "Small-cell lung carcinoma: inhibition of proliferation by vasoactive intestinal peptide and helodermin and enhancement of inhibition by anti-bombesin antibody". Life Sci. 52 (24): PL267–71. PMID 8389407.
  20. ^ Bond, Aaron (2006). "Exenatide (Byetta) as a novel treatment option for type 2 diabetes mellitus". Baylor University Medical Center Proceedings. 19 (3): 281–4. PMID 17252050. {{cite journal}}: Unknown parameter |month= ignored (help)
  21. ^ "Drug Derived From Gila Monster Saliva Helps Diabetics Control Glucose, Lose Weight". Science Daily. 2007-07-12.
  22. ^ Seward, Mark (2002). Dr. Mark Seward's Gila monster Propagation: How To Breed Gila monsters in Captivity. Natural Selections Publishing. p. 80. ISBN 0970139500.
  23. ^ Beck, D.D. (1990). "Ecology and behavior of the Gila monster in southwestern Utah". Journal of Herpetology. 24: 54–68. doi:10.2307/1564290.
  24. ^ Beck, D.D. (1995). "Locomotor performance and activity energetics of helodermatid lizards". Copeia. 1995 (577–585). {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  25. ^ a b c "San Diego Zoo's Animal Bytes: Gila Monster". San Diego Zoo. Retrieved 2008-05-19.
  26. ^ "Gila Monster - Heloderma suspectum". Sedgwick County Zoo. Retrieved 2008-06-09.
  27. ^ Brennan, Thomas C. "Reptiles of Arizona - Gila Monster (Heloderma suspectum)". Retrieved 2008-06-10.

Template:Reflink

Further reading

Wikispecies has information related to Heloderma suspectum.
Wikimedia Commons has media related to Heloderma suspectum.
  • Beck, Daniel D. (2005). Biology of Gila Monsters and Beaded Lizards. Berkeley: University of California Press. ISBN 0-520-24357-9.
  • Capula, Massimo (1989). Simon & Schuster's Guide to Reptiles and Amphibians of the World. New York: Simon & Schuster. ISBN 0671690981. {{cite book}}: Cite has empty unknown parameter: |1= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  • Carmony, Neil B.; Brown, David (1991). Gila Monster: Facts and Folklore of America's Aztec Lizard. Silver City, NM: High-Lonesome Books. ISBN 0-944383-18-1.{{cite book}}: CS1 maint: multiple names: authors list (link)
  • Cogger, Harold; Zweifel, Richard (1992). Reptiles & Amphibians. Sydney, Australia: Weldon Owen. ISBN 0831727861.
  • Ditmars, Raymond L (1933). Reptiles of the World: The Crocodilians, Lizards, Snakes, Turtles and Tortoises of the Eastern and Western Hemispheres. New York: Macmillian. p. 321.
  • Freiberg, Dr. Marcos; Walls, Jerry (1984). The World of Venomous Animals. New Jersey: TFH Publications. ISBN 0876665679.
  • Roever, J. M.; Hiser, Iona Seibert (1972). The Gila Monster. Austin, Tex: Steck-Vaughn Co. ISBN 0-8114-7739-8.{{cite book}}: CS1 maint: multiple names: authors list (link)
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