Editing Visible spectrum (section)

==In non-humans==
{{See also|Evolution of color vision}}
The visible spectrum is defined as that visible to humans, but the variance between species is large. Not only can [[cone opsin]]s be spectrally shifted to alter the visible range, but [[vertebrate]]s with 4 cones (tetrachromatic) or 2 cones (dichromatic) relative to humans' 3 (trichromatic) will also tend to have a wider or narrower visible spectrum than humans, respectively.

Vertebrates tend to have 1-4 different opsin classes:<ref name="Hunt-2001"/>
* longwave sensitive (LWS) with peak sensitivity between 500–570&nbsp;nm,
* middlewave sensitive (MWS) with peak sensitivity between 480–520&nbsp;nm,
* shortwave sensitive (SWS) with peak sensitivity between 415–470&nbsp;nm, and
* violet/ultraviolet sensitive (VS/UVS) with peak sensitivity between 355–435&nbsp;nm.
Testing the visual systems of animals behaviorally is difficult, so the visible range of animals is usually estimated by comparing the peak wavelengths of opsins with those of typical humans (S-opsin at 420&nbsp;nm and L-opsin at 560&nbsp;nm).

===Mammals===
Most mammals have retained only two opsin classes (LWS and VS), due likely to the [[nocturnal bottleneck]]. However, old world primates (including humans) have since evolved two versions in the LWS class to regain trichromacy.<ref name="Hunt-2001"/> Unlike most mammals, rodents' UVS opsins have remained at shorter wavelengths. Along with their lack of UV filters in the lens, mice have a UVS opsin that can detect down to 340&nbsp;nm. While allowing UV light to reach the retina can lead to retinal damage, the short lifespan of mice compared with other mammals may minimize this disadvantage relative to the advantage of UV vision.<ref>{{cite journal |last1=Gouras |first1=Peter |last2=Ekesten |first2=Bjorn |title=Why do mice have ultra-violet vision? |journal=Experimental Eye Research |date=December 2004 |volume=79 |issue=6 |pages=887–892 |doi=10.1016/j.exer.2004.06.031|pmid=15642326 }}</ref> Dogs have two cone opsins at 429&nbsp;nm and 555&nbsp;nm, so see almost the entire visible spectrum of humans, despite being dichromatic.<ref>{{cite journal |last1=Neitz |first1=Jay |last2=Geist |first2=Timothy |last3=Jacobs |first3=Gerald H. |title=Color vision in the dog |journal=Visual Neuroscience |date=August 1989 |volume=3 |issue=2 |pages=119–125 |doi=10.1017/S0952523800004430|pmid=2487095 |s2cid=23509491 }}</ref> Horses have two cone opsins at 428&nbsp;nm and 539&nbsp;nm, yielding a slightly more truncated red vision.<ref>{{cite journal |last1=Carroll |first1=Joseph |last2=Murphy |first2=Christopher J. |last3=Neitz |first3=Maureen |last4=Ver Hoeve |first4=James N. |last5=Neitz |first5=Jay |title=Photopigment basis for dichromatic color vision in the horse |journal=Journal of Vision |date=3 October 2001 |volume=1 |issue=2 |pages=80–87 |doi=10.1167/1.2.2|pmid=12678603 |doi-access=free |s2cid=8503174 }}</ref>

===Birds===
{{see also|Bird vision#Ultraviolet sensitivity}}
Most other vertebrates (birds, lizards, fish, etc.) have retained their [[tetrachromacy]], including UVS opsins that extend further into the ultraviolet than humans' VS opsin.<ref name="Hunt-2001"/> The sensitivity of avian UVS opsins vary greatly, from 355–425&nbsp;nm, and LWS opsins from 560–570&nbsp;nm.<ref name="Hart-2007">{{cite journal |last1=Hart |first1=Nathan S. |last2=Hunt |first2=David M. |title=Avian Visual Pigments: Characteristics, Spectral Tuning, and Evolution |journal=The American Naturalist |date=January 2007 |volume=169 |issue=S1 |pages=S7–S26 |doi=10.1086/510141|pmid=19426092 |bibcode=2007ANat..169S...7H |s2cid=25779190 |citeseerx=10.1.1.502.4314 }}</ref> This translates to some birds with a visible spectrum on par with humans, and other birds with greatly expanded sensitivity to UV light. The LWS opsin of birds is sometimes reported to have a peak wavelength above 600&nbsp;nm, but this is an effective peak wavelength that incorporates the filter of avian [[oil droplet]]s.<ref name="Hart-2007"/> The peak wavelength of the LWS opsin alone is the better predictor of the long-wave limit. A possible benefit of avian UV vision involves sex-dependent markings on their [[plumage]] that are visible only in the ultraviolet range.<ref>{{cite book|last=Cuthill|first=Innes C |author-link=Innes Cuthill |editor=Peter J.B. Slater|title=Advances in the Study of Behavior|publisher=Academic Press|location=Oxford, England|year=1997|volume=29|chapter=Ultraviolet vision in birds|page=161|isbn=978-0-12-004529-7}}</ref><ref>{{cite book|last=Jamieson|first=Barrie G. M. |title=Reproductive Biology and Phylogeny of Birds|publisher=University of Virginia|location=Charlottesville VA|year=2007|page=128|isbn=978-1-57808-386-2}}</ref>

===Fish===
{{see also|Vision in fish#Ultraviolet}}
[[Teleost]]s (bony fish) are generally tetrachromatic. The sensitivity of fish UVS opsins vary from 347-383 nm, and LWS opsins from 500-570 nm.<ref name="Carleton-2020">{{cite journal |last1=Carleton |first1=Karen L. |last2=Escobar-Camacho |first2=Daniel |last3=Stieb |first3=Sara M. |last4=Cortesi |first4=Fabio |last5=Marshall |first5=N. Justin |title=Seeing the rainbow: mechanisms underlying spectral sensitivity in teleost fishes |journal=Journal of Experimental Biology |date=15 April 2020 |volume=223 |issue=8 |doi=10.1242/jeb.193334|pmid=32327561 |pmc=7188444 |bibcode=2020JExpB.223B3334C }}</ref> However, some fish that use alternative [[chromophore]]s can extend their LWS opsin sensitivity to 625 nm.<ref name="Carleton-2020"/> The popular belief that the common goldfish is the only animal that can see both infrared and ultraviolet light<ref>{{cite web |url=http://www.skeptive.com/disputes/4484 |title=True or False? "The common goldfish is the only animal that can see both infra-red and ultra-violet light." |work= Skeptive |date=2013|access-date=September 28, 2013 |archive-url=https://web.archive.org/web/20131224110616/http://www.skeptive.com/disputes/4484 |archive-date=December 24, 2013 |url-status=usurped |df=mdy-all }}</ref> is incorrect, because goldfish cannot see infrared light.<ref>{{cite book |last=Neumeyer |first=Christa |editor1-first=Olga |editor1-last=Lazareva |editor2-first=Toru |editor2-last=Shimizu |editor3-first=Edward |editor3-last=Wasserman |title= How Animals See the World: Comparative Behavior, Biology, and Evolution of Vision |publisher=Oxford Scholarship Online |year=2012 |chapter=Chapter 2: Color Vision in Goldfish and Other Vertebrates |isbn= 978-0-19-533465-4}}</ref>

===Invertebrates===
The visual systems of invertebrates deviate greatly from vertebrates, so direct comparisons are difficult. However, UV sensitivity has been reported in most insect species.<ref>{{cite journal |last1=Briscoe |first1=Adriana D. |last2=Chittka |first2=Lars |title=The evolution of color vision in insects |journal=Annual Review of Entomology |date=January 2001 |volume=46 |issue=1 |pages=471–510 |doi=10.1146/annurev.ento.46.1.471|pmid=11112177 }}</ref>
[[Bee]]s and many other insects can detect ultraviolet light, which helps them find [[nectar]] in flowers. Plant species that depend on insect pollination may owe reproductive success to their appearance in ultraviolet light rather than how colorful they appear to humans. Bees' long-wave limit is at about 590&nbsp;nm.<ref>{{cite journal |last1=Skorupski|first1=Peter|last2=Chittka|first2=Lars|date=10 August 2010 |title=Photoreceptor Spectral Sensitivity in the Bumblebee, ''Bombus impatiens'' (Hymenoptera: Apidae) |journal=PLOS ONE |volume=5 |issue=8 |pages=e12049 |doi=10.1371/journal.pone.0012049 |pmid=20711523|pmc=2919406|bibcode = 2010PLoSO...512049S |doi-access=free}}</ref> [[Mantis shrimp]] exhibit up to 14 opsins, enabling a visible range of less than 300 nm to above 700 nm.<ref name="Hunt-2001"/>

===Thermal vision===
{{main|Infrared sensing in snakes}}
Some snakes can "see"<ref>{{cite journal | pmc = 2693128 | pmid=7256281 | volume=213 | issue=4509 | title=Integration of visual and infrared information in bimodal neurons in the rattlesnake optic tectum | year=1981 | journal=Science | pages=789–91 | last1 = Newman | first1 = EA | last2 = Hartline | first2 = PH | doi=10.1126/science.7256281| bibcode=1981Sci...213..789N }}</ref> radiant heat at [[wavelength]]s between 5 and 30&nbsp;[[μm]] to a degree of accuracy such that a blind [[rattlesnake]] can target vulnerable body parts of the prey at which it strikes,<ref name="Kardong-1991">{{cite journal | last1 = Kardong | first1 = KV | last2 = Mackessy | first2 = SP | year = 1991 | title = The strike behavior of a congenitally blind rattlesnake | journal = Journal of Herpetology | volume = 25 | issue = 2| pages = 208–211 | doi=10.2307/1564650| jstor = 1564650 }}</ref> and other snakes with the organ may detect warm bodies from a meter away.<ref>{{cite journal|doi=10.1038/news.2010.122 |title=Snake infrared detection unravelled |author=Fang, Janet |journal=Nature News|date=14 March 2010 }}</ref> It may also be used in [[thermoregulation]] and [[predator]] detection.<ref name="Krochmal-2004">{{cite journal|last=Krochmal|first=Aaron R.|author2=George S. Bakken |author3=Travis J. LaDuc |title=Heat in evolution's kitchen: evolutionary perspectives on the functions and origin of the facial pit of pitvipers (Viperidae: Crotalinae)|journal=Journal of Experimental Biology |date=15 November 2004|volume=207|pages=4231–4238|doi=10.1242/jeb.01278|pmid=15531644|issue=Pt 24|doi-access=free|bibcode=2004JExpB.207.4231K }}</ref><ref name="Gre92">Greene HW. (1992). "The ecological and behavioral context for pitviper evolution", in Campbell JA, Brodie ED Jr. ''Biology of the Pitvipers''. Texas: Selva. {{ISBN|0-9630537-0-1}}.</ref>