Editing Salamander

{{short description|Order of amphibians}}
{{For|the mythical lizard|Cultural depictions of salamanders}}
{{other uses}}
{{Good article}}
{{use dmy dates|date=June 2024}}
{{Automatic taxobox
| name = Salamanders
| fossil_range = <br/>[[Middle Jurassic]] – [[Holocene|Present]],<ref>{{Cite journal|last1=Jia|first1=Jia|last2=Anderson|first2=Jason S.|last3=Gao|first3=Ke-Qin|date=2021-07-23|title=Middle Jurassic stem hynobiids from China shed light on the evolution of basal salamanders|journal=iScience|language=English|volume=24|issue=7|page=102744 |doi=10.1016/j.isci.2021.102744|pmid=34278256 |pmc=8264161 |issn=2589-0042|doi-access=free|bibcode=2021iSci...24j2744J }}</ref> {{Fossil range|168|0}}
| image = SpottedSalamander.jpg
| image_caption = [[Spotted salamander]], ''Ambystoma maculatum''
| taxon = Urodela
| authority = [[André Marie Constant Duméril|Duméril]], 1806
| range_map = Cypron-Range Caudata.svg
| range_map_caption = Native distribution of salamanders (in green)
| subdivision_ranks = Suborders
| subdivision =
[[Cryptobranchoidea]]<br/>
[[Salamandroidea]]<br/>
[[Sirenoidea]]<br/>
}}

'''Salamanders''' are a group of [[amphibian]]s typically characterized by their [[lizard]]-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults.  All ten extant salamander families are grouped together under the [[order (biology)|order]] '''Urodela''', the sole surviving order from the group [[Caudata]].<ref name="AOTW">{{cite web |url= https://amphibiansoftheworld.amnh.org/Amphibia/Caudata/ |title= Caudata |last= Frost |first= Darrel R. |date= 2023 |orig-date= 1998 |website= Amphibian Species of the World |publisher= [[American Museum of Natural History]] |access-date= 22 March 2023 |archive-date= 22 March 2023 |archive-url= https://web.archive.org/web/20230322073805/https://amphibiansoftheworld.amnh.org/Amphibia/Caudata/ |url-status= live }}</ref> ''Urodela'' is a scientific Latin term based on the Ancient Greek {{lang|grc|οὐρά}} {{lang|grc|δήλη}}: ourà dēlē "conspicuous tail". ''Caudata'' is the Latin for "tailed ones", from {{lang|la|cauda}}: "tail".

Salamander diversity is highest in eastern [[North America]], especially in the [[Appalachian Mountains]]; most [[species]] are found in the [[Holarctic realm]], with some species present in the [[Neotropical realm]]. Salamanders never have more than four toes on their front legs and five on their rear legs,<ref>[https://books.google.com/books?id=na3v39RVqFEC&dq=Modern+amphibians+maximum+four+digits+manus+pes&pg=PA343 Life Traces of the Georgia Coast: Revealing the Unseen Lives of Plants and Animals]</ref> but some species have fewer digits and others lack hind limbs. Their permeable skin usually makes them reliant on habitats in or near water or other cool, damp places. Some salamander species are fully aquatic throughout their lives, some take to the water intermittently, and others are entirely terrestrial as adults.

This group of amphibians is capable of [[regeneration (biology)|regenerating]] lost limbs as well as other damaged parts of their bodies. Researchers hope to reverse engineer the regenerative processes for potential human medical applications, such as brain and spinal cord injury treatment or preventing harmful scarring during heart surgery recovery.<ref>{{cite web |url=http://www.livescience.com/34513-how-salamanders-regenerate-lost-limbs.html |title=Missing Parts? Salamander Regeneration Secret Revealed |date=20 May 2013 |website=[[Live Science]] |access-date=15 July 2018 |archive-date=16 July 2018 |archive-url=https://web.archive.org/web/20180716082245/https://www.livescience.com/34513-how-salamanders-regenerate-lost-limbs.html |url-status=live }}</ref> The remarkable ability of salamanders to regenerate is not just limited to limbs but extends to vital organs such as the heart, jaw, and parts of the spinal cord, showing their uniqueness compared to different types of vertebrates. ⁤⁤This ability is most remarkable for occurring without any type of scarring. ⁤⁤This has made salamanders an invaluable model organism in scientific research aimed at understanding and achieving regenerative processes for medical advancements in human and animal biology.<ref>{{cite journal |last1=Zhong |first1=Jixing |last2=Aires |first2=Rita |last3=Tsissios |first3=Georgios |last4=Skoufa |first4=Evangelia |last5=Brandt |first5=Kerstin |last6=Sandoval-Guzmán |first6=Tatiana |last7=Aztekin |first7=Can |title=Multi-species atlas resolves an axolotl limb development and regeneration paradox |journal=Nature Communications |date=10 October 2023 |volume=14 |issue=1 |page=6346 |doi=10.1038/s41467-023-41944-w |pmid=37816738 |pmc=10564727 |bibcode=2023NatCo..14.6346Z }}</ref>

Members of the [[Family (biology)|family]] [[Salamandridae]] are mostly known as [[newt]]s and lack the [[costal groove]]s along the sides of their bodies typical of other groups. The skin of some species contains the powerful poison [[tetrodotoxin]]; these salamanders tend to be slow-moving and have bright [[warning coloration]] to advertise their toxicity. Salamanders typically lay eggs in water and have aquatic larvae, but great variation occurs in their [[Biological life cycle|lifecycles]]. Some species in harsh environments reproduce while still in the larval state.

== Etymology ==
The word ''salamander'' comes from Old French ''salamandre'' from Latin ''salamandra'' from Greek {{lang|el|σαλαμάνδρα}} : salamándra, of uncertain, possibly, pre-Greek origin.<ref>{{OEtymD|salamander|access-date=22 March 2023}}</ref> The Greek word is used for the [[fire salamander]].<ref>{{cite web |url=https://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0057:entry=salama/ndra |title=σαλαμάνδρα |last1=Liddell |first1=Henry George |last2=Scott |first2=Robert |work=A Greek-English Lexicon |publisher=Perseus Digital Library |date=1940 |access-date=2023-03-22 |archive-date=2023-03-12 |archive-url=https://web.archive.org/web/20230312093032/https://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0057:entry=salama/ndra |url-status=live }}</ref>

== Description ==
[[File:Salamandra lanzai13.jpg|thumb|X-ray image of salamander]]
The skin lacks scales and is moist and smooth to the touch, except in [[newt]]s of the Salamandridae, which may have velvety or warty skin, wet to the touch. The skin may be drab or brightly colored, exhibiting various patterns of stripes, bars, spots, blotches, or dots. Male newts become dramatically colored during the breeding season. Cave species dwelling in darkness lack pigmentation and have a translucent pink or pearlescent appearance.<ref name="EoR pp.60–68">{{cite book |editor1=Cogger, H. G. |editor2=Zweifel, R. G. |author1=Lanza, B. |author2=Vanni, S. |author3=Nistri, A. |year=1998 |title=Encyclopedia of Reptiles and Amphibians |publisher= Academic Press |pages=60–68 |isbn= 978-0-12-178560-4}}</ref>

Salamanders range in size from the [[minute salamanders]], with a total length of {{convert|27|mm|in|frac=8|abbr=on}}, including the tail, to the [[Chinese giant salamander]] which reaches {{convert|1.8|m|ft|0|abbr=on}} and weighs up to {{convert|65|kg|lb|round=5|abbr=on}}. All the largest species are found in the four families [[giant salamander]]s, [[Sirenidae|sirens]], [[Amphiuma|Congo eels]] and [[Proteidae]], who are all aquatic and obligate paedomorphs.<ref>[https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/dvdy.373 Repeated ecological and life cycle transitions make salamanders an ideal model for evolution and development]</ref><ref>[https://pubmed.ncbi.nlm.nih.gov/22151821/ Metabolism, gas exchange, and acid-base balance of giant salamanders]</ref> Some of the largest terrestrial salamanders, which goes through full metamorphosis, belongs to the family of [[Pacific giant salamander]]s, and are much smaller.<ref>[https://books.google.com/books?id=gZ_hX7xifDMC&dq=Giant+Salamanders+%28Family+Dicamptodontidae%29&pg=PA84 Field Guide to Amphibians and Reptiles of California: Revised Edition]</ref> Most salamanders are between {{convert|10|and|20|cm|in|0|abbr=on}} in length.<ref name=stebbins3>Stebbins & Cohen (1995) p. 3</ref>

===Trunk, limbs and tail===
An adult salamander generally resembles a small lizard, having a basal [[tetrapod]] body form with a cylindrical trunk, four limbs, and a long tail. Except in the family Salamandridae, the head, body, and tail have a number of vertical depressions in the surface which run from the mid-dorsal region to the ventral area and are known as [[costal groove]]s. Their function seems to be to help keep the skin moist by channeling water over the surface of the body.<ref>{{cite journal |author1=Lopez, Carl H. |author2=Brodie, Edmund D. Jr. |year=1972 |title=The Function of Costal Grooves in Salamanders (Amphibia, Urodela) |journal=Journal of Herpetology |volume=11 |issue=3 |pages=372–374 |jstor=1563252 | doi = 10.2307/1563252 }}</ref>

[[File:S lacertina USGS.jpg|thumb|right|[[Sirenidae|Sirens]] have an eel-like appearance.]]
Some aquatic species, such as [[Sirenidae|sirens]] and [[amphiuma]]s, have reduced or absent hind limbs, giving them an [[eel]]-like appearance, but in most species, the front and rear limbs are about the same length and project sideward, barely raising the trunk off the ground. The feet are broad with short digits, usually four on the front feet and five on the rear. Salamanders do not have claws, and the shape of the foot varies according to the animal's habitat. Climbing species have elongated, square-tipped toes, while rock-dwellers have larger feet with short, blunt toes. The [[Bolitoglossa|tree-climbing salamander]] (''Bolitoglossa'' sp.) has plate-like webbed feet which adhere to smooth surfaces by suction, while the rock-climbing ''[[Hydromantes]]'' species from California have feet with fleshy webs and short digits and use their tails as an extra limb. When ascending, the tail props up the rear of the body, while one hind foot moves forward and then swings to the other side to provide support as the other hind foot advances.<ref name=stebbins30>Stebbins & Cohen (1995) pp. 26–30</ref>

In larvae and aquatic salamanders, the tail is laterally flattened, has dorsal and ventral fins, and undulates from side to side to propel the animal through the water. In the families [[Ambystomatidae]] and Salamandridae, the male's tail, which is larger than that of the female, is used during the [[Amplexus|amplexus embrace]] to propel the mating couple to a secluded location. In terrestrial species, the tail moves to counterbalance the animal as it runs, while in the [[arboreal salamander]] and other tree-climbing species, it is [[Prehensile tail|prehensile]]. The tail is also used by certain [[Lungless salamander|plethodontid salamanders]] that can jump, to help launch themselves into the air.<ref name=stebbins30/> The tail is used in [[courtship display|courtship]] and as a storage organ for proteins and lipids. It also functions as a defense against predation, when it may be lashed at the attacker or [[Autotomy|autotomised]] when grabbed. Unlike frogs, an adult salamander is able to regenerate limbs and its tail when these are lost.<ref name=stebbins30/>

===Skin===
[[File:Taricha granulosa (Rough-skinned newt).JPG|thumb|left|upright|[[Rough-skinned newt]]]]
The skin of salamanders, in common with other amphibians, is thin, permeable to water, serves as a respiratory membrane, and is well-supplied with glands. It has highly [[cornified]] outer layers, renewed periodically through a [[Moulting|skin shedding]] process controlled by hormones from the [[pituitary]] and [[thyroid]] glands. During moulting, the skin initially breaks around the mouth, and the animal moves forward through the gap to shed the skin. When the front limbs have been worked clear, a series of body ripples pushes the skin toward the rear. The hind limbs are extracted and push the skin farther back, before it is eventually freed by friction as the salamander moves forward with the tail pressed against the ground.<ref name=stebbins16>Stebbins & Cohen (1995) pp. 10–16</ref> The animal often then eats the resulting sloughed skin.<ref name="EoR pp.60–68"/>

[[Mucous gland|Glands]] in the skin discharge [[mucus]] which keeps the skin moist, an important factor in skin respiration and thermoregulation. The sticky layer helps protect against bacterial infections and molds, reduces friction when swimming, and makes the animal slippery and more difficult for predators to catch. Granular glands scattered on the upper surface, particularly the head, back, and tail, produce repellent or toxic secretions.<ref name="stebbins16"/> Some salamander toxins are particularly potent. The [[rough-skinned newt]] (''Taricha granulosa'') produces the neurotoxin [[tetrodotoxin]], the most toxic nonprotein substance known. Handling the newts does no harm, but ingestion of even a minute fragment of skin is deadly. In feeding trials, fish, frogs, reptiles, birds, and mammals were all found to be susceptible.<ref>{{cite journal |author= Brodie, Edmund D. Jr. |year=1968 |title=Investigations on the skin toxin of the adult rough-skinned newt, ''Taricha granulosa'' |journal=Copeia |volume=1968 |issue=2 |pages=307–313 |jstor=1441757 |doi= 10.2307/1441757 |s2cid=52235877 }}</ref>

Mature adults of some salamander species have "nuptial" glandular tissue in their [[cloaca]]e, at the base of their tails, on their heads or under their chins. Some females release [[pheromone|chemical substances]], possibly from the ventral cloacal gland, to attract males, but males do not seem to use pheromones for this purpose.<ref name=Kentwood>{{cite book |title=The Ecology and Behavior of Amphibians |last=Wells |first=Kentwood, D. |year=2010 |publisher=University of Chicago Press |isbn=978-0-226-89333-4 |pages=411–417 |url=https://books.google.com/books?id=eDKEKy5JJbIC&pg=PA411 }}</ref> In some [[Plethodontidae|plethodonts]], males have conspicuous mental glands on the chin which are pressed against the females' nostrils during the courtship ritual. They may function to speed up the mating process, reducing the risk of its being disrupted by a predator or rival male.<ref>{{cite journal |author1=León, Ezequiel González |author2=Ramírez-Pinilla, Martha Patricia |year=2009 |title=The mental gland of ''Bolitoglossa nicefori'' (Caudata: Plethodontidae) |journal=Amphibia-Reptilia |volume=30 |issue=4 |pages=561–569 |doi=10.1163/156853809789647013 |doi-access=free }}</ref> The gland at the base of the tail in ''[[Plethodon cinereus]]'' is used to mark [[fecal pellets]] to proclaim territorial ownership.<ref name=Kentwood/>

===Senses===
[[File:P anguinus-head1.jpg|thumb|right|The front part of the [[olm]]'s head carries sensitive chemo-, mechano-, and electroreceptors.]]
[[File:Biofluorescent patterns across salamander diversity and anatomy - 41598 2020 59528 Fig1.jpg|thumb|[[Biofluorescence]] can be observed across various salamander species]]
====Smell====
[[Olfaction]] in salamanders plays a role in territory maintenance, the recognition of predators, and courtship rituals, but is probably secondary to sight during prey selection and feeding. Salamanders have two types of sensory areas that respond to the chemistry of the environment. Olfactory epithelium in the nasal cavity picks up airborne and aquatic odors, while adjoining [[vomeronasal organ]]s detect nonvolatile chemical cues, such as tastes in the mouth. In plethodonts, the sensory epithelium of the vomeronasal organs extends to the [[Nasolabial fold|nasolabial grooves]], which stretch from the nostrils to the corners of the mouth. These extended areas seem to be associated with the identification of prey items, the recognition of [[conspecifics]], and the identification of individuals.<ref name=stebbins40>Stebbins & Cohen (1995) pp. 37–40</ref>

====Vision====
The eyes of most salamanders are adapted primarily for vision at night. In some permanently aquatic species, they are reduced in size and have a simplified [[retina]]l structure, and in cave dwellers such as the [[Georgia blind salamander]], they are absent or covered with a layer of skin. In amphibious species, the eyes are a compromise and are [[nearsighted]] in air and [[farsighted]] in water. Fully terrestrial species such as the [[fire salamander]] have a flatter lens which can focus over a much wider range of distances.<ref name=stebbins44>Stebbins & Cohen (1995) pp. 42–44</ref>
To find their prey, salamanders use [[trichromatic]] [[color vision]] extending into the [[ultraviolet]] range, based on three [[photoreceptor cell|photoreceptor]] types that are maximally sensitive around 450, 500, and 570&nbsp;nm.<ref>{{cite journal |author1=Przyrembel, C. |author2=Keller, B. |author3=Neumeyer, C. |year=1995 |title=Trichromatic color vision in the salamander (''Salamandra salamandra'') |journal=Journal of Comparative Physiology |volume=176 |issue=4 |pages=575–586 |doi=10.1007/BF00196422 |s2cid=749622 }}</ref> The larvae, and the adults of some highly aquatic species, also have a [[lateral line]] organ, similar to that of fish, which can detect changes in water pressure.<ref name="EoR pp.60–68"/>

====Hearing====
All salamanders lack middle ear cavity, [[Tympanum (anatomy)|eardrum]] and [[eustachian tube]], but have an opercularis system like frogs, and are still able to detect airborne sound.<ref>{{cite book|url=https://books.google.com/books?id=0ps6AwAAQBAJ&q=%22all+salamanders+lack+the+middle+ear+cavity%22&pg=PT227|title=Amphibian Evolution: The Life of Early Land Vertebrates|first=Rainer R.|last=Schoch|date=19 March 2014|publisher=John Wiley & Sons|access-date=15 July 2018|via=Google Books|isbn=9781118759134}}</ref><ref>{{cite web|url=https://www.sciencedaily.com/releases/2015/02/150206125257.htm|title=Researchers reveal how hearing evolved|website=sciencedaily.com|access-date=15 July 2018|archive-date=16 July 2018|archive-url=https://web.archive.org/web/20180716025457/https://www.sciencedaily.com/releases/2015/02/150206125257.htm|url-status=live}}</ref> The opercularis system consists of two ossicles: the columella (equivalent to the [[stapes]] of [[higher vertebrates]]) which is fused to the skull, and the operculum. An opercularis muscle connects the latter to the pectoral girdle, and is kept under tension when the animal is alert.<ref>{{cite journal |author1=Becker, R. P. |author2=Lombard, R. E. |year=1977 |title=Structural correlates of function in the "opercularis" muscle of amphibians |journal=Cell and Tissue Research |volume=175 |issue=4 |pages=499–522 |pmid=830429 |doi=10.1007/bf00222415|s2cid=25650919 }}</ref> The system seems able to detect low-frequency vibrations (500–600&nbsp;Hz), which may be picked up from the ground by the fore limbs and transmitted to the inner ear. These may serve to warn the animal of an approaching predator.<ref name=stebbins72>Stebbins & Cohen (1995) pp. 69–72</ref>

====Vocalization====
Salamanders are usually considered to have no voice and do not use sound for communication in the way that frogs do. Before mating, they communicate by pheromone signaling; some species make quiet ticking, clicking, squeaks or popping noises,<ref name=":2" /> perhaps by the opening and closing of valves in the nose. Most salamanders lack vocal cords, but a larynx is present in the mudpuppy (Necturus) and some other species, and the Pacific giant salamanders and a few others have a large larynx and bands known as plicae vocales.<ref>[https://books.google.com/books?id=Rur4DwAAQBAJ&dq=Pacific+giant+salamander+larynx+bands+plicae+vocales&pg=PA123 Vertebrate Biology: Systematics, Taxonomy, Natural History, and Conservation]</ref> The [[California giant salamander]] can produce a bark or rattle, and a few species can squeak by contracting muscles in the throat. The arboreal salamander can squeak using a different mechanism; it retracts its eyes into its head, forcing air out of its mouth. The [[Ensatina|ensatina salamander]] occasionally makes a hissing sound, while the [[Siren (genus)|sirens]] sometimes produce quiet clicks, and can resort to faint shrieks if attacked. Similar clicking behaviour was observed in two European newts ''[[Lissotriton vulgaris]]'' and ''[[Ichthyosaura alpestris]]'' in their aquatic phase.<ref name=":2">{{cite journal |author1=Hubáček, J. |author2=Šugerková, M. |author3=Gvoždík, L. |year=2019 |title=Underwater sound production varies within not between species in sympatric newts |journal=PeerJ |volume=7 |page=e6649 |doi=10.7717/peerj.6649|pmid=30944780 |pmc=6441559 |doi-access=free }}</ref> Vocalization in salamanders has been little studied and the purpose of these sounds is presumed to be the startling of predators.<ref name=stebbins77>Stebbins & Cohen (1995) pp. 76–77</ref>

[[File:Salamander -QDB.JPG|thumb|upright|Salamanders need moist environments to respire through their skin.]]

===Respiration===
[[Respiration (physiology)|Respiration]] differs among the different species of salamanders, and can involve gills, lungs, skin, and the membranes of mouth and throat. Larval salamanders breathe primarily by means of [[gill]]s, which are usually external and feathery in appearance. Water is drawn in through the mouth and flows out through the gill slits. Some [[neotenic]] species such as the [[mudpuppy]] (''Necturus maculosus'') retain their gills throughout their lives, but most species lose them at [[metamorphosis]]. The [[embryo]]s of some terrestrial lungless salamanders, such as ''Ensatina'', that undergo direct development, have large gills that lie close to the egg's surface.<ref name=stebbins25>Stebbins & Cohen (1995) pp. 17–25</ref>

When present in adult salamanders, lungs vary greatly among different species in size and structure. In aquatic, cold-water species like the [[torrent salamander]]s (''Rhyacotriton''), the lungs are very small with smooth walls, while species living in warm water with little dissolved oxygen, such as the [[lesser siren]] (''Siren intermedia''), have large lungs with convoluted surfaces. In the lungless salamanders ([[Family (biology)|family]] [[Plethodontidae]] and the [[clawed salamander]]s in the family of [[Asiatic salamander]]s), no lungs or gills are present, and [[gas exchange]] mostly takes place through the skin, known as [[cutaneous respiration]], supplemented by the tissues lining the mouth. To facilitate this, these salamanders have a dense network of blood vessels just under the skin and in the mouth.<ref name="stebbins25" /><ref>Cogger & Zweifel (1998), pp. 74–75.</ref><ref>{{Cite journal |title=Patterns of Natural Selection on Mitochondrial Protein-Coding Genes in Lungless Salamanders: Relaxed Purifying Selection and Presence of Positively Selected Codon Sites in the Family Plethodontidae |date=2021 |doi=10.1155/2021/6671300 |doi-access=free |last1=Kakehashi |first1=Ryosuke |last2=Kurabayashi |first2=Atsushi |journal=International Journal of Genomics |volume=2021 |pages=1–12 |pmid=33928143 |pmc=8053045 }}</ref>

In the [[amphiuma]]s, metamorphosis is incomplete, and they retain one pair of [[gill slit]]s as adults, with fully functioning internal lungs.<ref>{{Cite journal|last=Toews|first=Daniel P.|date=1974|title=Respiratory Mechanisms in the Aquatic Salamander, Amphiuma tridactylum|journal=Copeia|volume=1974|issue=4|pages=917–920|doi=10.2307/1442591|jstor=1442591}}</ref> Some species that lack lungs respire through gills. In most cases, these are external gills, visible as tufts on either side of the head. Some terrestrial salamanders have lungs used in respiration, although these are simple and sac-like, unlike the more complex organs found in [[mammal]]s. Many species, such as the [[olm]], have both lungs and gills as adults.<ref name="EoR pp.60–68"/>

[[File:Levatores arcuum of Necturus maculosus.png|thumb|upright|A dissected view of the levatores arcuum muscles in a ''Necturus maculosus'' specimen. These (shown in the purple circles) move the external gills, as a means of respiration.]]

In the ''Necturus'', external gills begin to form as a means of combating hypoxia in the egg as egg yolk is converted into metabolically active tissue.<ref>{{Cite journal|last1=Rogge|first1=Jessica R.|last2=Warkentin|first2=Karen M.|date=2008-11-15|title=External gills and adaptive embryo behavior facilitate synchronous development and hatching plasticity under respiratory constraint|journal=Journal of Experimental Biology|volume=211|issue=22|pages=3627–3635|doi=10.1242/jeb.020958|issn=0022-0949|pmid=18978228|doi-access=free}}</ref> Molecular changes in the mudpuppy during post-embryonic development primarily due to the [[thyroid gland]] prevent the internalization of the external gills as seen in most salamanders that undergo metamorphosis.<ref name=":12">{{Cite book|title=Biology of Amphibians|last=Duellman|first=William Edward|publisher=The Johns Hopkins University Press |year=1994 }}</ref> The external gills seen in salamanders differs greatly from that of amphibians with internalized gills. Unlike amphibians with internalized gills which typically rely on the changing of pressures within the buccal and pharyngeal cavities to ensure diffusion of oxygen onto the gill curtain, neotenic salamanders such as Necturus use specified musculature, such as the levatores arcuum, to move external gills to keep the respiratory surfaces constantly in contact with new oxygenated water.<ref>{{Cite book|title=Vertebrates : comparative anatomy, function, evolution|last=V.|first=Kardong, Kenneth|date=2012|publisher=McGraw-Hill|isbn=9780073524238|oclc=939087630}}</ref><ref>{{Cite book|title=Comparative vertebrate anatomy a laboratory dissection guide|author=Zalisko, Edward J. |date=2015|publisher=McGraw-Hill Education|isbn=9780077657055|oclc=935173274}}</ref>

==Feeding and diet==
Salamanders are opportunistic [[predators]]. They are generally not restricted to specific foods, but feed on almost any organism of a reasonable size.<ref name=Hairston>{{cite journal |author=Hairston, Nelson G. |year=1949 |title=The local distribution and ecology of the plethodontid salamanders of the southern Appalachians |journal=Ecological Monographs |volume=19 |issue=1 |pages=47–73 |doi=10.2307/1943584 |jstor=1943584 |bibcode=1949EcoM...19...47H }}</ref> Large species such as the [[Japanese giant salamander]] (''Andrias japonicus'') eat crabs, fish, small mammals, amphibians, and aquatic insects.<ref>{{cite web |url=http://amphibiaweb.org/cgi/amphib_query?where-genus=Andrias&where-species=japonicus |title=Plethodontidae |publisher=AmphibiaWeb |access-date=2014-02-09 |archive-date=2014-02-22 |archive-url=https://web.archive.org/web/20140222145222/http://amphibiaweb.org/cgi/amphib_query?where-genus=Andrias&where-species=japonicus |url-status=live }}</ref> In a study of smaller [[dusky salamander]]s (''Desmognathus'') in the [[Appalachian Mountains]], their diet includes [[earthworm]]s, [[flies]], [[beetles]], beetle larvae, [[leafhopper]]s, [[springtail]]s, [[moth]]s, [[spider]]s, [[grasshopper]]s, and [[mite]]s.<ref name=Hairston/> [[Cannibalism]] sometimes takes place, especially when resources are short or time is limited. Tiger salamander tadpoles in ephemeral pools sometimes resort to eating each other, and are seemingly able to target unrelated individuals.<ref>{{cite web |url=http://askabiologist.asu.edu/explore/he-aint-tasty-hes-my-brother |title=He ain't tasty, he's my brother |author=Koppes, Steve |work=Ask a Biologist |publisher=Arizona State University |access-date=2014-02-08 |date=2009-09-24 |archive-date=2014-02-22 |archive-url=https://web.archive.org/web/20140222044743/http://askabiologist.asu.edu/explore/he-aint-tasty-hes-my-brother |url-status=live }}</ref> Adult [[blackbelly salamander]]s (''Desmognathus quadramaculatus'') prey on adults and young of other species of salamanders, while their larvae sometimes cannibalise smaller larvae.<ref>{{cite web |url=http://amphibiaweb.org/cgi-bin/amphib_query?where-genus=Desmognathus&where-species=quadramaculatus&rel-genus=equals&rel-species=equals |title=''Desmognathus quadramaculatus'' |publisher=AmphibiaWeb |access-date=2014-02-09 |archive-date=2014-02-22 |archive-url=https://web.archive.org/web/20140222145214/http://amphibiaweb.org/cgi-bin/amphib_query?where-genus=Desmognathus&where-species=quadramaculatus&rel-genus=equals&rel-species=equals |url-status=live }}</ref>

[[File:Salamander head.png|thumb|The head of a tiger salamander]]

Most species of salamander have small teeth in both their upper and lower jaws. Unlike [[frog]]s, even the larvae of salamanders possess these teeth.<ref name="EoR pp.60–68"/> Although larval teeth are shaped like pointed cones, the teeth of adults are adapted to enable them to readily grasp prey. The [[crown (dentistry)|crown]], which has two cusps (bicuspid), is attached to a pedicel by [[collagen]]ous fibers. The joint formed between the bicuspid and the pedicel is partially flexible, as it can bend inward, but not outward. When struggling prey is advanced into the salamander's mouth, the teeth tips relax and bend in the same direction, encouraging movement toward the throat, and resisting the prey's escape.<ref>Kardong (2009), pp. 505–506.</ref> Many salamanders have patches of teeth attached to the [[vomer]] and the [[palatine bone]]s in the roof of the mouth, and these help to retain prey. All types of teeth are resorbed and replaced at intervals throughout the animal's life.<ref name=stebbins58>Stebbins & Cohen (1995) pp. 57–58</ref>

A terrestrial salamander catches its prey by flicking out its sticky [[tongue]] in an action that takes less than half a second. In some species, the tongue is attached anteriorly to the floor of the mouth, while in others, it is mounted on a pedicel. It is rendered sticky by secretions of mucus from glands in its tip and on the roof of the mouth.<ref name=stebbins60>Stebbins & Cohen (1995) pp. 58–60</ref> High-speed [[cinematography]] shows how the [[tiger salamander]] (''Ambystoma tigrinum'') positions itself with its snout close to its prey. Its mouth then gapes widely, the lower jaw remains stationary, and the tongue bulges and changes shape as it shoots forward. The protruded tongue has a central depression, and the rim of this collapses inward as the target is struck, trapping the prey in a mucus-laden trough. Here it is held while the animal's neck is flexed, the tongue retracted and jaws closed. Large or resistant prey is retained by the teeth while repeated protrusions and retractions of the tongue draw it in. Swallowing involves alternate contraction and relaxation of muscles in the throat, assisted by depression of the eyeballs into the roof of the mouth.<ref>{{cite journal |author1=Larsen, John H. jr. |author2=Guthrie, Dan J. |year=1975 |title=The feeding system of terrestrial tiger salamanders (''Ambystoma tigrinum melanostictum'' baird) |journal=Journal of Morphology |volume=147 |issue=2 |pages=137–153 |doi=10.1002/jmor.1051470203 |pmid=30309060 |s2cid=52959566 }}</ref> Many lungless salamanders of the family Plethodontidae have more elaborate feeding methods. Muscles surrounding the [[hyoid bone]] contract to store elastic energy in springy connective tissue, and actually "shoot" the hyoid bone out of the mouth, thus elongating the tongue.<ref>{{cite journal | last1 = Deban | first1 = S.M. | last2 = Wake | first2 = D.B. | last3 = Roth | first3 = G. | year = 1997 | title = Salamander with a ballistic tongue | doi = 10.1038/37898 | journal = Nature | volume = 389 | issue = 6646| pages = 27–28 | bibcode = 1997Natur.389...27D | s2cid = 205026166 }}</ref><ref>{{cite journal | last1 = Deban | first1 = S. M. | last2 = O'Reilly | first2 = U. Dicke | year = 2007 | title = Extremely high-power tongue projection in plethodontid salamanders | journal = Journal of Experimental Biology | volume = 210 | issue = 4| pages = 655–667 | doi=10.1242/jeb.02664 | pmid=17267651| doi-access = free }}</ref> Muscles that originate in the pelvic region and insert in the tongue are used to reel the tongue and the hyoid back to their original positions.<ref name=Regal>{{cite journal |author=Regal, Philip J. |year=1966 |title=Feeding specializations and the classification of terrestrial salamanders |journal=Evolution |volume=20 |issue=3 |pages=392–407 |jstor=2406638 |doi=10.2307/2406638|pmid=28562974 }}</ref>

An aquatic salamander lacks muscles in the tongue, and captures its prey in an entirely different manner. It grabs the food item, grasps it with its teeth, and adopts a kind of inertial feeding. This involves tossing its head about, drawing water sharply in and out of its mouth, and snapping its jaws, all of which tend to tear and macerate the prey, which is then swallowed.<ref name=Regal/>

Though frequently feeding on slow-moving animals like [[snails]], [[shrimps]] and [[worm]]s, [[sirenids]] are unique among salamanders for having developed herbivory speciations, such as beak-like jaw ends and extensive intestines. They feed on algae and other soft-plants in the wild, and easily eat offered [[lettuce]].<ref>{{cite journal | last1 = Hill | first1 = R. L. | last2 = Mendelson | first2 = J. R. | last3 = Stabile | first3 = J. L. | year = 2015 | title = Direct observation and review of herbivory in Sirenidae (Amphibia: Caudata) | journal = Southeastern Naturalist | volume = 14 | pages = N5–N9 | doi=10.1656/058.014.0104| s2cid = 86233204 }}</ref>

==Defense==
{{Further|Antipredator adaptations}}
Salamanders have thin skins and soft bodies, move rather slowly and might appear vulnerable to opportunistic predation, but have several effective lines of defense. Mucus coating on damp skin makes them difficult to grasp, and the slimy coating may have an offensive taste or be toxic. When attacked by a predator, a salamander may position itself to make the main poison glands face the aggressor. Often, these are on the tail, which may be waggled or turned up and arched over the animal's back. The sacrifice of the tail may be a worthwhile strategy, if the salamander escapes with its life and the predator learns to avoid that species of salamander in the future.<ref name=stebbins120>Stebbins & Cohen (1995) pp. 110–120</ref>

===Aposematism===
{{Further|Aposematism}}
[[File:Salamander-olympus.jpg|thumb|A [[fire salamander]]'s striking black and yellow pattern [[Aposematism|warns off predators]]]]

Skin secretions of the tiger salamander (''Ambystoma tigrinum'') fed to rats have been shown to produce aversion to the flavor, and the rats avoided the presentational medium when it was offered to them again.<ref>{{cite journal |author1=Mason, J. Russell |author2=Rabin, Michael D. |author3=Stevens, David A. |year=1982 |title=Conditioned taste aversions: skin secretions used for defense by tiger salamanders, ''Ambystoma tigrinum'' |journal=Copeia |volume=1982 |issue=3 |pages=667–671 |jstor=1444668 | doi = 10.2307/1444668 }}</ref> The fire salamander (''Salamandra salamandra'') has a ridge of large granular glands down its spine which are able to squirt a fine jet of toxic fluid at its attacker. By angling its body appropriately, it can accurately direct the spray for a distance of up to {{convert|80|cm|in|-1|abbr=on}}.<ref>{{cite journal |author1=Brodie, Edmund D. Jr. |author2-link=Neal Smatresk |author2=Smatresk, Neal J. |year=1990 |title=The antipredator arsenal of fire salamanders: spraying of secretions from highly pressurized dorsal skin glands |journal=Herpetologica |volume=46 |issue=1 |pages=1–7 |jstor=3892595 }}</ref>

The [[Iberian ribbed newt]] (''Pleurodeles waltl'') has another method of deterring aggressors. Its skin exudes a poisonous, viscous fluid and at the same time, the newt rotates its sharply pointed ribs through an angle between 27 and 92°, and adopts an inflated posture. This action causes the ribs to puncture the body wall, each rib protruding through an orange wart arranged in a lateral row. This may provide an [[aposematic]] signal that makes the spines more visible. When the danger has passed, the ribs retract and the skin heals.<ref>{{cite journal |author1=Heiss, E. |author2=Natchev, N. |author3=Salaberger, D. |author4=Gumpenberger, M. |author5=Rabanser, A. |author6=Weisgram, J. |year=2010 |title=Hurt yourself to hurt your enemy: new insights on the function of the bizarre antipredator mechanism in the salamandrid ''Pleurodeles waltl'' |journal=Journal of Zoology |volume=280 |issue=2 |pages=156–162 |doi=10.1111/j.1469-7998.2009.00631.x |doi-access=free }}</ref>

===Camouflage and mimicry===
{{Further|Camouflage|mimicry}}

Although many salamanders have [[crypsis|cryptic]] colors so as to be unnoticeable, others [[aposematism|signal their toxicity]] by their [[animal coloration|vivid coloring]]. Yellow, orange, and red are the colors generally used, often with black for greater contrast. Sometimes, the animal postures if attacked, revealing a flash of warning hue on its underside. The red eft, the brightly colored terrestrial juvenile form of the [[eastern newt]] (''Notophthalmus viridescens''), is highly poisonous. It is avoided by birds and snakes, and can survive for up to 30 minutes after being swallowed (later being regurgitated).<ref name=Howard>{{cite journal |author1=Howard, Ronnie R. |author2=Brodie, Edmund D. Jr. |year=1973 |title=A Batesian mimetic complex in salamanders: responses of avian predators |journal=Herpetologica |volume=29 |issue=1 |pages=33–41 |jstor=3891196 }}</ref> The [[red salamander]] (''Pseudotriton ruber'') is a palatable species with a similar coloring to the red eft. Predators that previously fed on it have been shown to avoid it after encountering red efts, an example of [[Batesian mimicry]].<ref name=Howard/> Other species exhibit similar mimicry. In California, the palatable yellow-eyed salamander (''Ensatina eschscholtzii'') closely resembles the toxic [[California newt]] (''Taricha torosa'') and the rough-skinned newt (''Taricha granulosa''), whereas in other parts of its range, it is cryptically colored.<ref>{{cite journal |author1=Kuchta, S. R. |author2=Krakauer, A. H. |author3=Sinervo, B |year=2008 |title=Why does the yellow-eyed ensatina have yellow eyes? Batesian mimicry of Pacific newts (genus ''Trachia'') by the salamander ''Ensatina eschscholtzii xanthoptica'' |journal=Evolution |volume=62 |issue=4 |pages=984–990 |doi=10.1111/j.1558-5646.2008.00338.x |pmid=18248632 |s2cid=998486 |doi-access=free }}</ref> A correlation exists between the toxicity of Californian salamander species and [[diurnality|diurnal]] habits: relatively harmless species like the [[California slender salamander]] (''Batrachoseps attenuatus'') are [[nocturnal]] and are eaten by snakes, while the California newt has many large poison glands in its skin, is diurnal, and is avoided by snakes.<ref>Cott, 1940. Page 204.</ref>

===Autotomy===
{{Further|Autotomy}}

Some salamander species use tail autotomy to escape predators. The tail drops off and wriggles around for a while after an attack, and the salamander either runs away or stays still enough not to be noticed while the predator is distracted. The tail regrows with time, and salamanders routinely regenerate other complex tissues, including the [[Lens (anatomy)|lens]] or [[retina]] of the eye. Within only a few weeks of losing a piece of a limb, a salamander perfectly reforms the missing structure.<ref>{{cite journal |doi=10.1186/1741-7007-7-1 |title=Microarray and cDNA sequence analysis of transcription during nerve-dependent limb regeneration |year=2009 |last1=Monaghan|first1=James R.|last2=Epp|first2=Leonard G. |last3=Putta| first3=Srikrishna |last4=Page |first4=Robert B. |last5=Walker |first5=John A. |last6=Beachy |first6=Chris K. |last7=Zhu |first7=Wei |last8=Pao |first8=Gerald M. |last9=Verma |first9=Inder M. |last10=Hunter |first10=Tony |last11=Bryant |first11=Susan V. |last12=Gardiner |first12=David M. |last13=Harkins |first13=Tim T. |last14=Voss |first14=S. Randal |journal=BMC Biology |volume=7 |issue=1 |pages=1 |pmid=19144100 |pmc=2630914 |doi-access=free }}</ref>

==Distribution and habitat==

Salamanders split off from the other amphibians during the mid- to late Permian, and initially were similar to modern members of the [[Cryptobranchoidea]]. Their resemblance to [[lizard]]s is the result of [[symplesiomorphy]], their common retention of the primitive tetrapod body plan, but they are no more closely related to lizards than they are to mammals. Their nearest relatives are the frogs and toads, within [[Batrachia]]. 

The oldest known total-group ([[Caudata]]) salamander is ''[[Triassurus]]'' from the Triassic of [[Kyrgyzstan]].<ref name=Schoch2020>{{cite journal |last1=Schoch |first1=Rainer R. |last2=Werneburg |first2=Ralf |last3=Voigt |first3=Sebastian |title=A Triassic stem-salamander from Kyrgyzstan and the origin of salamanders |journal=Proceedings of the National Academy of Sciences |date=2020 |volume=117 |issue=21 |pages=11584–11588 |doi=10.1073/pnas.2001424117|pmid=32393623 |pmc=7261083 |bibcode=2020PNAS..11711584S |doi-access=free }}</ref> Further salamander fossils are known from the Middle [[Jurassic]] of [[England]],<ref>{{cite journal | last1 = Evans | first1 = S. E. | last2 = Milner | first2 = A. R. | last3 = Mussett | first3 = F. | year = 1988 | title = The earliest known salamanders (Amphibia, Caudata): a record from the Middle Jurassic of England | journal = Geobios | volume = 21 | issue = 5| pages = 539–552 | doi=10.1016/s0016-6995(88)80069-x | bibcode = 1988Geobi..21..539E }}</ref>  [[Scotland]],<ref name="Jonesetal2022">{{Cite journal |last1=Jones |first1=Marc E. H. |last2=Benson |first2=Roger B. J. |last3=Skutschas |first3=Pavel |last4=Hill |first4=Lucy |last5=Panciroli |first5=Elsa |last6=Schmitt |first6=Armin D. |last7=Walsh |first7=Stig A. |last8=Evans |first8=Susan E. |date=2022-07-11 |title=Middle Jurassic fossils document an early stage in salamander evolution |journal=Proceedings of the National Academy of Sciences |volume=119 |issue=30 |pages=e2114100119 |doi=10.1073/pnas.2114100119 |issn=0027-8424|doi-access=free |pmid=35858401 |pmc=9335269 |bibcode=2022PNAS..11914100J }}</ref> [[China]],<ref name="gao&shubin2012">{{cite journal|author1=Gao, Ke-Qin |author2=Shubin, Neil H. |doi=10.1073/pnas.1009828109 |title=Late Jurassic salamandroid from western Liaoning, China |year=2012 |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=109 |issue=15 |pages=5767–5772 |pmid=22411790 |pmc=3326464|bibcode=2012PNAS..109.5767G |doi-access=free }}</ref> and [[Kazakhstan]].<ref>{{cite journal | last1 = Marjanovic | first1 = D. | last2 = Laurin | first2 = M. | year = 2014 | title = An updated paleontological timetree of lissamphibians, with comments on the anatomy of Jurassic crown-group salamanders (Urodela) | journal = Historical Biology | volume = 26 | issue = 4 | pages = 535–550 | doi = 10.1080/08912963.2013.797972| bibcode = 2014HBio...26..535M | s2cid = 84581331 }}</ref> The oldest known crown-group salamander ([[Urodela]]) remains uncertain but recent analyses suggest it is ''[[Valdotriton]]'' from the Late [[Jurassic]] of [[Spain]].<ref name=Jonesetal2022/>

Salamanders are found only in the [[Holarctic]] and [[Neotropical]] regions, not reaching south of the [[Mediterranean Basin]], the [[Himalayas]], or in [[South America]] the [[Amazon Basin]]. They do not extend north of the Arctic [[tree line]], with the northernmost Asian species, ''[[Salamandrella keyserlingii]]'', which can survive long-term freezing at −55 °C,<ref>{{Cite journal |last1=Shekhovtsov |first1=Sergei V. |last2=Bulakhova |first2=Nina A. |last3=Tsentalovich |first3=Yuri P. |last4=Zelentsova |first4=Ekaterina A. |last5=Meshcheryakova |first5=Ekaterina N. |last6=Poluboyarova |first6=Tatiana V. |last7=Berman |first7=Daniil I. |date=2021-11-12 |title=Biochemical Response to Freezing in the Siberian Salamander Salamandrella keyserlingii |journal=Biology |volume=10 |issue=11 |pages=1172 |doi=10.3390/biology10111172 |doi-access=free |pmc=8614755 |pmid=34827165}}</ref> occurring in the [[Siberian larch]] forests of [[Sakha Republic|Sakha]] and the most northerly species in North America, ''[[Ambystoma laterale]]'', reaching no farther north than [[Labrador]] and ''[[Taricha granulosa]]'' not beyond the [[Alaska Panhandle]].<ref>{{cite book |title=The Ecology and Behavior of Amphibians |last=Wells |first=Kentwood D. |year=2007 |publisher=University of Chicago Press |isbn=978-0-226-89334-1 |page=130 }}</ref> They had an exclusively [[Laurasia]]n distribution until ''[[Bolitoglossa]]'' invaded South America from Central America, probably by the start of the [[Early Miocene]], about 23 million years ago.<ref name="Elmer2013">{{cite journal|last1=Elmer|first1=K. R.|last2=Bonett|first2=R. M.|last3=Wake|first3=D. B.|last4=Lougheed|first4=S. C.|title=Early Miocene origin and cryptic diversification of South American salamanders|journal=BMC Evolutionary Biology|volume=13|issue=1|date=2013-03-04|pages=59|doi=10.1186/1471-2148-13-59|pmid=23497060|pmc=3602097 |doi-access=free |bibcode=2013BMCEE..13...59E }}</ref> They also lived on the [[Caribbean Islands]] during the early [[Miocene]] epoch, confirmed by the discovery of ''[[Palaeoplethodon hispaniolae]]'',<ref>{{Cite web|url=http://oregonstate.edu/ua/ncs/archives/2015/aug/first-ever-discovery-salamander-amber-sheds-light-evolution-caribbean-islands|title=First-ever discovery of a salamander in amber sheds light on evolution of Caribbean islands {{!}} News and Research Communications {{!}} Oregon State University|website=oregonstate.edu|access-date=2016-03-25|date=2015-08-17|archive-date=2017-02-19|archive-url=https://web.archive.org/web/20170219132815/http://oregonstate.edu/ua/ncs/archives/2015/aug/first-ever-discovery-salamander-amber-sheds-light-evolution-caribbean-islands|url-status=live}}</ref> found trapped in [[amber]] in the [[Dominican Republic]]. Vertebrae fossils recovered from the [[Murgon fossil site]] have been tentatively attributed to that of a Salamander,<ref>{{cite journal |last=Boles |first=W. E. |year=1997 |title=Fossil songbirds (Passeriformes) from the early Eocene of Australia |journal=[[Emu (journal)|Emu]] |volume=97 |issue=1 |pages=43–50 |doi=10.1071/MU97004 |bibcode=1997EmuAO..97...43B |issn=0158-4197}}</ref> though its true identity is disputed. If the vertebrae truly belong to a Salamander, they would represent the only Salamanders in [[Australia]].

There are about 760 living species of salamander.<ref>{{cite web |url=https://amphibiaweb.org/amphibian/speciesnums.html |title=Species by number |publisher=AmphibiaWeb |access-date=2021-01-11 |archive-date=2021-01-12 |archive-url=https://web.archive.org/web/20210112181312/https://amphibiaweb.org/amphibian/speciesnums.html |url-status=live }}</ref><ref name=Naish2013>{{cite news |title=The amazing world of salamanders |author=Naish, Darren |url=http://blogs.scientificamerican.com/tetrapod-zoology/2013/10/01/amazing-world-of-salamanders/ |newspaper=Scientific American |date=2013-10-01 |access-date=2014-01-14 |archive-date=2014-01-16 |archive-url=https://web.archive.org/web/20140116082325/http://blogs.scientificamerican.com/tetrapod-zoology/2013/10/01/amazing-world-of-salamanders/ |url-status=live }}</ref> One-third of the known salamander species are found in North America. The highest concentration of these is found in the Appalachian Mountains region, where the Plethodontidae are thought to have originated in mountain streams. Here, vegetation zones and proximity to water are of greater importance than altitude. Only species that adopted a more terrestrial mode of life have been able to disperse to other localities. The [[northern slimy salamander]] (''Plethodon glutinosus'') has a wide range and occupies a habitat similar to that of the [[southern gray-cheeked salamander]] (''Plethodon metcalfi''). The latter is restricted to the slightly cooler and wetter conditions in north-facing [[Cove (Appalachian Mountains)|cove forests]] in the southern Appalachians, and to higher elevations above 900&nbsp;m (3,000&nbsp;ft), while the former is more adaptable, and would be perfectly able to inhabit these locations, but some unknown factor seems to prevent the two species from co-existing.<ref name=Hairston/>

One species, the [[Anderson's salamander]], is one of the few species of living amphibians to occur in brackish or salt water.<ref>Brad Shaffer; Oscar Flores-Villela; Gabriela Parra-Olea; David Wake (2004). "Ambystoma andersoni". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature</ref>

==Reproduction and development==
{{see also|Sexual selection in amphibians}}
[[File:US-CA-NevadaCity-NewtAmplexus.jpg|thumb|right|Sierra newt [[amplexus]] found in stream at Woolman Semester in Nevada County, California]]

Many salamanders do not use vocalisations,<ref>{{cite journal |author=Bradley, J. Gavin; Eason, Perri K. |year=2018 |title=''Eurycea lucifuga'' (Cave Salamander) Vocalization |journal=Herpetological Review |volume=49 |issue=4 |pages=725 |url=https://www.researchgate.net/publication/329876505 }}</ref> and in most species the sexes look alike, so they use olfactory and tactile cues to identify potential mates, and [[sexual selection]] occurs. Pheromones play an important part in the process and may be produced by the abdominal gland in males and by the cloacal glands and skin in both sexes. Males are sometimes to be seen investigating potential mates with their snouts. In Old World newts, ''[[Triturus]]'' spp., the males are [[sexually dimorphic]] and display in front of the females. Visual cues are also thought to be important in some ''[[Plethodont]]'' species.<ref name=stebbins154>Stebbins & Cohen (1995) pp. 143–154</ref>

Except for terrestrial species in the three families [[Plethodontidae]], [[Ambystomatidae]], and [[Salamandridae]], salamanders mate in water.<ref>{{Cite book|url=https://books.google.com/books?id=KwOkDwAAQBAJ&dq=Plethodontidae+Ambystomatidae+Salamandridae+mate+in+water&pg=PA206 | title=Chemical Signals in Vertebrates 14 | isbn=9783030176167 | last1=Buesching | first1=Christina D. | date=19 July 2019 | publisher=Springer }}</ref> The mating varies from courtship between a single male and female to explosive group breeding.<ref>{{Cite web |url=https://mds.marshall.edu/cgi/viewcontent.cgi?article=1501&context=etd |title=Examining the Influence of Mating Systems on Testes Size in Salamanders |access-date=2023-02-16 |archive-date=2023-02-16 |archive-url=https://web.archive.org/web/20230216224937/https://mds.marshall.edu/cgi/viewcontent.cgi?article=1501&context=etd |url-status=live }}</ref> In the clade [[Salamandroidea]], which makes up about 90% of all species, fertilization is internal.<ref>{{Cite journal |title=Middle Jurassic stem hynobiids from China shed light on the evolution of basal salamanders |date=2021 |doi=10.1016/j.isci.2021.102744 |last1=Jia |first1=Jia |last2=Anderson |first2=Jason S. |last3=Gao |first3=Ke-Qin |journal=iScience |volume=24 |issue=7 |pmid=34278256 |pmc=8264161 |bibcode=2021iSci...24j2744J }}</ref> As a general rule, salamanders with internal fertilization have indirect sperm transfer, but in species like the [[Sardinian brook salamander]], the [[Corsican brook salamander]], the [[Caucasian salamander]] and the [[Pyrenean brook salamander]], the male transfers his sperm directly into the female cloaca.<ref>{{Cite web |url=https://zoologicalbulletin.de/BzB_Volumes/Volume_57_2/119_126_BzB57_2_K%C3%BChnel_Susanne_et_al.PDF |title=Evolutionary reproductive morphology of amphibians |access-date=2023-02-15 |archive-date=2023-03-07 |archive-url=https://web.archive.org/web/20230307115508/https://zoologicalbulletin.de/BzB_Volumes/Volume_57_2/119_126_BzB57_2_K%C3%BChnel_Susanne_et_al.PDF |url-status=live }}</ref><ref>{{Cite journal |doi=10.1643/0045-8511(2003)003[0149:AASDIA]2.0.CO;2 |title=Age and Sexual Dimorphism in a Population of Euproctus platycephalus (Caudata: Salamandridae) from Sardinia |date=2003 |last1=Bovero |first1=S. |last2=Sotgiu |first2=G. |last3=Castellano |first3=S. |last4=Giacoma |first4=C. |journal=Copeia |volume=2003 |pages=149–154 |s2cid=85909830 }}</ref><ref>{{cite book|url=https://books.google.com/books?id=eDKEKy5JJbIC&dq=Salamandra+luschani+fleshy+cloaca+Calotriton+asper+copulation&pg=PA439 | title=The Ecology and Behavior of Amphibians | isbn=9780226893334 | last1=Wells | first1=Kentwood D. | date=15 February 2010 | publisher=University of Chicago Press }}</ref> For the species with indirect sperm transfer, the male deposits a [[spermatophore]] on the ground or in the water according to species, and the female picks this up with her vent. The spermatophore has a packet of sperm supported on a conical gelatinous base, and often an elaborate courtship behavior is involved in its deposition and collection. Once inside the cloaca, the [[spermatozoa]] move to the [[spermatheca]], one or more chambers in the roof of the cloaca, where they [[female sperm storage|are stored]] for sometimes lengthy periods until the eggs are laid. In the [[Asiatic salamander]]s, the [[giant salamander]]s and [[Sirenidae]], which are the most primitive groups, the fertilization is external. In a reproductive process similar to that of typical frogs, the male releases sperm onto the egg mass. These salamanders also have males that exhibit [[parental care]], which otherwise only occur in females with internal fertilization.<ref name=stebbins154/><ref>{{Cite journal |title=The evolution of parental care in salamanders - Nature |journal=Scientific Reports |date=5 October 2022 |volume=12 |issue=1 |page=16655 |doi=10.1038/s41598-022-20903-3 |last1=Vági |first1=Balázs |last2=Marsh |first2=Daniel |last3=Katona |first3=Gergely |last4=Végvári |first4=Zsolt |last5=Freckleton |first5=Robert P. |last6=Liker |first6=András |last7=Székely |first7=Tamás |pmid=36198742 |pmc=9535019 }}</ref>

Three different types of egg deposition occur. ''[[Ambystoma]]'' and ''[[Taricha]]'' spp. spawn large numbers of small eggs in quiet ponds where many large predators are unlikely. Most [[dusky salamanders]] (''Desmognathus'') and [[Pacific giant salamander]]s (''Dicamptodon'') lay smaller batches of medium-sized eggs in a concealed site in flowing water, and these are usually guarded by an adult, normally the female. Many of the tropical climbing salamanders (''Bolitoglossa'') and lungless salamanders (Plethodontinae) lay a small number of large eggs on land in a well-hidden spot, where they are also guarded by the mother.<ref name=stebbins154/> Some species such as the [[Salamandra|fire salamanders]] (''Salamandra'') are [[ovoviviparous]], with the female retaining the eggs inside her body until they hatch, either into larvae to be deposited in a water body, or into fully formed juveniles.<ref name="EoR pp.60–68"/>

[[File:Embryonic development of a salamander, filmed in the 1920s.ogv|thumb|left|Embryonic development of a salamander, filmed in the 1920s]]

In temperate regions, reproduction is usually seasonal and salamanders may migrate to breeding grounds. Males usually arrive first and in some instances set up [[Territory (animal)|territories]]. Typically, a larval stage follows in which the organism is fully aquatic. The tadpole has three pairs of external gills, no eyelids, a long body, a laterally flattened tail with dorsal and ventral fins and in some species limb-buds or limbs. Pond-type larvae may have a pair of rod-like balancers on either side of the head, long gill filaments and broad fins. Stream-type larvae are more slender with short gill filaments—in Rhyacotriton and Onychodactylus, and some species in Batrachuperus, the gills and gill rakers are extremely reduced,<ref>[https://books.google.com/books?id=x-ZhDwAAQBAJ&dq=Mountain-brook+larvae+salamander+extreme+reduction+external+gills&pg=PA485 Reproductive Biology and Phylogeny of Urodela]</ref> narrower fins and no balancers, but instead have hind limbs already developed when they hatch.<ref name=stebbins179>Stebbins & Cohen (1995) pp. 175–179</ref> The tadpoles are [[carnivorous]] and the larval stage may last from days to years, depending on species. Sometimes this stage is completely bypassed, and the eggs of most lungless salamanders (Plethodontidae) develop directly into miniature versions of the adult without an intervening larval stage.<ref>{{cite web |url=http://www.amphibiaweb.org/lists/Plethodontidae.shtml |title=Plethodontidae |publisher=AmphibiaWeb |access-date=2014-01-09 |archive-date=2015-06-09 |archive-url=https://web.archive.org/web/20150609125525/http://amphibiaweb.org/lists/Plethodontidae.shtml |url-status=live }}</ref>

By the end of the larval stage, the tadpoles already have limbs and [[metamorphosis]] takes place normally. In salamanders, this occurs over a short period of time and involves the closing of the gill slits and the loss of structures such as gills and tail fins that are not required as adults. At the same time, eyelids develop, the mouth becomes wider, a tongue appears, and teeth are formed. The aqueous larva emerges onto land as a terrestrial adult.<ref name=Kiyonaga>{{cite web |url=http://www.uoregon.edu/~titus/herp_old/neoteny.htm |author=Kiyonaga, Robin R. |title=Metamorphosis vs. neoteny (paedomorphosis) in salamanders (Caudata) |access-date=2008-05-04 |archive-date=2008-12-01 |archive-url=https://web.archive.org/web/20081201024633/http://www.uoregon.edu/~titus/herp_old/neoteny.htm |url-status=live }}</ref>

[[File:Axolotl Portrait.jpg|thumb|[[Neoteny|Neotenic]] [[axolotl]], showing external gills]]

Not all species of salamanders follow this path. [[Neoteny]], also known as paedomorphosis, has been observed in all salamander families, and may be universally possible in all salamander species. In this state, an individual may retain gills or other juvenile features while attaining reproductive maturity. The changes that take place at metamorphosis are under the control of [[thyroid hormone]]s and in obligate neotenes such as the [[axolotl]] (''Ambystoma mexicanum''), the tissues are seemingly unresponsive to the hormones. In other species, the changes may not be triggered because of underactivity of the hypothalamus-pituitary-thyroid mechanism which may occur when conditions in the terrestrial environment are too inhospitable.<ref name=Kiyonaga/> This may be due to cold or wildly fluctuating temperatures, aridity, lack of food, lack of cover, or insufficient [[iodine]] for the formation of thyroid hormones. Genetics may also play a part. The larvae of tiger salamanders (''Ambystoma tigrinum''), for example, develop limbs soon after hatching and in seasonal pools promptly undergo metamorphosis. Other larvae, especially in permanent pools and warmer climates, may not undergo metamorphosis until fully adult in size. Other populations in colder climates may not metamorphose at all, and become sexually mature while in their larval forms. Neoteny allows the species to survive even when the terrestrial environment is too harsh for the adults to thrive on land.<ref name=stebbins179/>

==Conservation==
[[File:Hellbender.jpg|thumb|left|The threatened hellbender]]

A general decline in living amphibian species has been linked with the fungal disease [[chytridiomycosis]]. A higher proportion of salamander species than of frogs or caecilians are in one of the at-risk categories established by the [[IUCN]]. Salamanders showed a significant diminution in numbers in the last few decades of the 20th century, although no direct link between the fungus and the population decline has yet been found.<ref name="Sandoval">{{cite journal |author1=Sandoval-Comte, Adriana |author2=Pineda, Eduardo |author3=Aguilar-López, José L. |year=2012 |title=In search of critically endangered species: the current situation of two tiny salamander species in the neotropical mountains of Mexico |journal=PLOS ONE |volume=7 |issue=4 |pages=e34023 |doi=10.1371/journal.pone.0034023 |pmid=22485155 |pmc=3317776 |bibcode=2012PLoSO...734023S |doi-access=free }}</ref> The IUCN made further efforts in 2005 as they established the Amphibian Conservation Action Plan (ACAP), which was subsequently followed by Amphibian Ark (AArk), Amphibian Specialist Group (ASG), and finally the umbrella organization known as the Amphibian Survival Alliance (ASA).<ref name=":0">{{Cite journal|title = Amphibians and conservation breeding programmes: do all threatened amphibians belong on the ark?|journal = Biodiversity and Conservation|date = 2015-07-24|issn = 0960-3115|pages = 2625–2646|volume = 24|issue = 11|doi = 10.1007/s10531-015-0966-9|first1 = Benjamin|last1 = Tapley|first2 = Kay S.|last2 = Bradfield|first3 = Christopher|last3 = Michaels|first4 = Mike|last4 = Bungard| bibcode=2015BiCon..24.2625T |s2cid = 11824410}}</ref> Researchers also cite [[deforestation]], resulting in fragmentation of suitable habitats, and [[climate change]] as possible contributory factors. Species such as ''[[Pseudoeurycea brunnata]]'' and ''[[Pseudoeurycea goebeli]]'' that had been abundant in the [[cloud forest]]s of Guatemala and Mexico during the 1970s were found by 2009 to be rare.<ref>{{cite news |title=Another Amphibian at Risk: Salamanders |author=Fountain, Henry |url=https://www.nytimes.com/2009/02/17/science/17obdecline.html?_r=0 |newspaper=The New York Times |date=2009-02-16 |access-date=2013-06-28 |archive-date=2013-11-26 |archive-url=https://web.archive.org/web/20131126193439/http://www.nytimes.com/2009/02/17/science/17obdecline.html?_r=0 |url-status=live }}</ref> Few data have been gathered on population sizes over the years and, by intensive surveying of historic and suitable new locations, it has been possible to locate individuals of other species, such as ''[[Parvimolge townsendi]]'', which had been thought to be [[extinct]].<ref name=Sandoval/> Currently, the major lines of defense for the conservation of Salamanders includes both [[In situ conservation|in situ]] and [[ex situ]] conservation methods. There are efforts in place for certain members of the Salamander family to be conserved under a conservation breeding program (CBP) but there should be research done ahead of time to determine if the Salamander species is actually going to value from the CBP, as researchers have noted that some species of amphibians completely fail in this environment.<ref name=":0" />

Various conservation initiatives are being attempted around the world. The [[Chinese giant salamander]], at 1.8&nbsp;m (6&nbsp;ft) the largest amphibian in the world, is [[critically endangered]], as it is collected for food and for use in [[traditional Chinese medicine]]. An environmental education programme is being undertaken to encourage sustainable management of wild populations in the [[Qinling Mountains]] and captive breeding programmes have been set up.<ref>{{cite web |url=http://www.zsl.org/conservation/regions/asia/chinese-giant-salamander,1821,AR.html |title=Chinese Giant Salamander |work=ZSL Conservation |publisher=Zoological Society of London |access-date=2013-07-21 |archive-date=2013-06-28 |archive-url=https://web.archive.org/web/20130628132518/http://www.zsl.org/conservation/regions/asia/chinese-giant-salamander,1821,AR.html |url-status=live }}</ref> The [[hellbender]] is another large, long-lived species with dwindling numbers and fewer juveniles reaching maturity than previously.<ref>{{cite journal |author1=Wheeler, Benjamin A. |author2=Prosen, Ethan |author3=Mathis, Alicia |author4=Wilkinson, Robert F. |year=2003 |title=Population declines of a long-lived salamander: a 20+-year study of hellbenders, ''Cryptobranchus alleganiensis'' |journal=Biological Conservation |volume=109 |issue=1 |pages=151–156 |doi=10.1016/s0006-3207(02)00136-2 |bibcode=2003BCons.109..151W }}</ref> Another alarming finding is the increase in abnormalities in up to 90% of the hellbender population in the [[Spring River (Arkansas)|Spring River]] watershed in Arkansas.<ref>{{cite journal |author1=Wheeler, Benjamin A. |author2=McCallum, Malcolm L. |author3=Trauth, Stanley E. |year=2002 |title=Abnormalities in the Ozark hellbender (''Ctyptobranchm alleganiensis bishopi'') in Arkansas: a comparison between two rivers with a historical perspective |journal=Journal of the Arkansas Academy of Science |volume=58 |pages=250–252 |url=https://scholarworks.uark.edu/jaas/vol59/iss1/13/ }}</ref> Habitat loss, silting of streams, pollution and disease have all been implicated in the decline and a captive breeding programme at [[Saint Louis Zoo]] has been successfully established.<ref>{{cite news |title=World's first captive breeding of Ozark hellbenders |url=https://www.sciencedaily.com/releases/2011/12/111201094756.htm |newspaper=Science Daily |date=2011-12-01 |access-date=2013-07-21 |archive-date=2013-05-11 |archive-url=https://web.archive.org/web/20130511202834/http://www.sciencedaily.com/releases/2011/12/111201094756.htm |url-status=live }}</ref> Of the 20 species of minute salamanders (''Thorius'' spp.) in Mexico, half are believed to have become extinct and most of the others are critically endangered. Specific reasons for the decline may include climate change, chytridiomycosis, or volcanic activity, but the main threat is [[habitat destruction]] as logging, agricultural activities, and human settlement reduce their often tiny, fragmented ranges. Survey work is being undertaken to assess the status of these salamanders, and to better understand the factors involved in their population declines, with a view to taking action.<ref>{{cite web |url=http://www.edgeofexistence.org/amphibian_conservation/lungless.php |title=Lungless salamanders of Mexico |work=EDGE: Evolutionary distinct and globally endangered |publisher=The Zoological Society of London |access-date=2013-07-21 |archive-url=https://web.archive.org/web/20130529163058/http://edgeofexistence.org/amphibian_conservation/lungless.php |archive-date=2013-05-29 |url-status=dead }}</ref>

''[[Ambystoma mexicanum]]'', an aquatic salamander, is a species protected under the Mexican UMA (Unit for Management and conservation of wildlife) as of April 1994. Another detrimental factor is that the axolotl lost their role as a top predator since the introduction of locally exotic species such as [[Nile tilapia]] and carp. Tilapia and carp directly compete with axolotls by consuming their eggs, larvae, and juveniles. Climate change has also immensely affected axolotls and their populations throughout the southern Mexico area. Due to its proximity to [[Mexico City]], officials are currently working on programs at Lake Xochimilco to bring in tourism and educate the local population on the restoration of the natural habitat of these creatures.<ref>{{Cite web|title = EDGE of Existence|url = http://www.edgeofexistence.org/amphibians/species_info.php?id=552#conservation_underway|website = EDGE of Existence|access-date = 2015-10-29|archive-date = 2015-11-17|archive-url = https://web.archive.org/web/20151117063535/http://www.edgeofexistence.org/amphibians/species_info.php?id=552#conservation_underway|url-status = live}}</ref> This proximity is a large factor that has impacted the survival of the axolotl, as the city has expanded to take over the Xochimilco region in order to make use of its resources for water and provision and sewage.<ref name=":1" /> It is farmed for use in research facilities and so may one day return to its natural habitat. The recent decline in population has substantially impacted genetic diversity among populations, making it difficult to further progress scientifically. Some genetic indiversity due to paedeomorphism in ''Ambystoma'' species such as the axolotl does not account for the overall lack of diversity. Evidence points toward a historical bottlenecking of ''Ambystoma'' that contributes to the variation issues and no longer a large genetic pool for it to pull from, thus raising concern for inbreeding due to lack of gene flow.<ref>{{Cite journal|title = Conservation genetics of threatened Mexican axolotls (''Ambystoma'')|journal = Animal Conservation|date = 2012-02-01|issn = 1469-1795|pages = 61–72|volume = 15|issue = 1|doi = 10.1111/j.1469-1795.2011.00488.x|first1 = G.|last1 = Parra-Olea|first2 = K. R.|last2 = Zamudio|first3 = E.|last3 = Recuero|first4 = X.|last4 = Aguilar-Miguel|first5 = D.|last5 = Huacuz|first6 = L.|last6 = Zambrano| bibcode=2012AnCon..15...61P | s2cid=46992721 }}</ref> One way researchers are looking into maintaining genetic diversity within the population is via cryopreservation of the spermatophores from the male axolotl. It is a safe and non-invasive method that requires the collection of the spermatophores and places them into a deep freeze for preservation. Most importantly, they have found that there is only limited damage done to the spermatophores upon thawing and thus it is a viable option. As of 2013, it is a method that is being used to save not only the axolotl but also numerous other members of the salamander family.<ref name=":1">{{Cite journal|title = Recent decline and potential distribution in the last remnant area of the microendemic Mexican axolotl (''Ambystoma mexicanum'')|journal = Biological Conservation|date = 2009-12-01|pages = 2881–2885|volume = 142|issue = 12|doi = 10.1016/j.biocon.2009.07.008|first1 = Victoria|last1 = Contreras|first2 = Enrique|last2 = Martínez-Meyer|first3 = Elsa|last3 = Valiente|first4 = Luis|last4 = Zambrano| bibcode=2009BCons.142.2881C }}</ref><ref>{{Cite journal |title = Response of a native endangered axolotl, ''Ambystoma mexicanum'' (Amphibia), to exotic fish predator|journal = Hydrobiologia |date = 2015-02-01|issn = 0018-8158|pages = 73–80|volume = 753|issue = 1|doi = 10.1007/s10750-015-2194-4|first1 = Guillermina|last1 = Alcaraz|first2 = Xarini|last2 = López-Portela| first3 = Cecilia|last3 = Robles-Mendoza|s2cid = 17468971 }}</ref><ref>{{Cite journal|url = http://www.herpconbio.org/Volume_8/Issue_3/Figiel_2013.pdf|title = Cryopreservation of Sperm from the Axolotl AmbystomA MexicAnum: ImpliCations for Conservation|last = Figiel|first = Chester|date = 2013|journal = Herpetological Conservation and Biology|access-date = 26 October 2015|archive-date = 22 March 2016|archive-url = https://web.archive.org/web/20160322155458/http://www.herpconbio.org/Volume_8/Issue_3/Figiel_2013.pdf|url-status = live}}</ref>

Research is being done on the environmental cues that have to be replicated before captive animals can be persuaded to breed. Common species such as the tiger salamander and the mudpuppy are being given hormones to stimulate the production of sperm and eggs, and the role of arginine [[vasotocin]] in courtship behaviour is being investigated. Another line of research is [[artificial insemination]], either ''[[in vitro]]'' or by inserting spermatophores into the cloacae of females. The results of this research may be used in captive-breeding programmes for endangered species.<ref>{{cite web |url=http://www.memphiszoo.org/salamanderconservation |title=Salamander Conservation |author1=Marcec, Ruth |author2=Bement, Hannah |work=Amphibian Conservation |publisher=Memphis Zoo |access-date=2013-07-21 |url-status=dead |archive-url=https://web.archive.org/web/20130731001027/http://www.memphiszoo.org/salamanderconservation |archive-date=2013-07-31 }}</ref>

== Taxonomy ==
The order name Urodela comes from the name Urodèles given by [[André Marie Constant Duméril]] in 1805,<ref name="AOTW"/> it is derived from the Greek words {{lang|el|οὐρά}} ''ourā́'' "tail" and {{lang|el|δῆλος}} ''dēlos'' "visible, conspicuous" because of their "persistent" tails.<ref name="Rice">{{cite book |last= Rice |first= Edward Loranus |author-link= Edward Loranus Rice |year= 1935 |title= An Introduction to Biology |url= https://books.google.com/books?id=x-s8AAAAYAAJ&q=urodela |location=Boston, Massachusetts, USA | publisher=Ginn and Company |page=253 }}</ref>

Disagreement exists among different authorities as to the definition of the terms Caudata and Urodela. Some maintain that the Urodela should be restricted to the [[crown group]], with the Caudata being used for the total group.<ref name="AOTW"/>{{citation needed |reason=This source doesn't support the claim. Frost argues Caudata is the valid name for the order with Urodela a synonym because the name is invalid. Dubois argues for Urodela as the name of order, with  Caudata as synonym and that it can't be used as an alternative name for the crown or total group |date=November 2023}} Others restrict the name Caudata to the crown group and use Urodela for the total group.<ref name="larson">{{Cite journal|author1=Larson, A. |author2=Dimmick, W. | year = 1993| title = Phylogenetic relationships of the salamander families: an analysis of the congruence among morphological and molecular characters| periodical = Herpetological Monographs|  volume =7| issue = 7| pages = 77–93| doi =10.2307/1466953| jstor =1466953}}</ref><ref name=Blackburn2011>{{cite journal |last1=Blackburn |first1=David C. |last2=Wake |first2=David B. |title=Class Amphibia Gray, 1825. In: Zhang, Z.-Q. (Ed.) Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness |journal=Zootaxa |date=23 December 2011 |volume=3148 |issue=1 |doi=10.11646/zootaxa.3148.1.8 }}</ref> The former approach seems to be most widely adopted and is used in this article.<ref name=Naish2013/>

The ten families belonging to Urodela are divided into three suborders.<ref name="larson" /> The clade Neocaudata is often used to separate the Cryptobranchoidea and Salamandroidea from the Sirenoidea.

{| class="wikitable" style="margin:1em auto;"
|colspan="100%" align="center" bgcolor="#BBBBFF"|'''[[Cryptobranchoidea]] (Giant salamanders)'''
|-
!Family!!Common names!!Example species!!
Example image
|-
|[[Cryptobranchidae]]||Giant salamanders||[[Hellbender]] (''Cryptobranchus alleganiensis'')|| [[File:Cryptobranchus alleganiensis.jpg|100px]]
|-
|[[Hynobiidae]]||Asiatic salamanders||[[Hida salamander]] (''Hynobius kimurae'')|| [[File:Hynobius kimurae (cropped) edit.jpg|100px]]
|-
|colspan="100%" align="center" bgcolor="#BBBBFF"|'''[[Salamandroidea]]''' (Advanced salamanders)
|-
|[[Ambystomatidae]]||Mole salamanders||[[Marbled salamander]] (''Ambystoma opacum'')||[[File:Ambystoma opacumPCSLXYB.jpg|100px]]
|-
|[[Amphiumidae]]||Amphiumas or Congo eels||[[Two-toed amphiuma]] (''Amphiuma means'')||[[File:Amphiuma means.jpg|100px]]
|-
|[[Plethodontidae]]||Lungless salamanders||[[Red-backed salamander]] (''Plethodon cinereus'')|| [[File:Plethodon cinereus.jpg|100px]]
|-
|[[Proteidae]]||Mudpuppies and olms||[[Olm]] (''Proteus anguinus'')||[[File:Proteus anguinus Postojnska Jama Slovenija.jpg|100px]]
|-
|[[Rhyacotritonidae]]||Torrent salamanders||[[Southern torrent salamander]] (''Rhyacotriton variegatus'')||[[File:Rhyacotriton variegatus.jpg|100px]]
|-
|[[Salamandridae]]||Newts and true salamanders||[[Alpine newt]] (''Ichthyosaura alpestris'')||[[File:Mesotriton aplestris dorsal view chrischan.jpeg|100px]]
|-
|colspan="100%" align="center" bgcolor="#BBBBFF"|'''[[Sirenoidea]]''' (Sirens)
|-
|[[Sirenidae]]||Sirens||[[Greater siren]] (''Siren lacertina'')||[[File:Sirenlacertina.jpg|100px]]
|-
|}<!-- if anyone knows how to quickly use template:clade and make a nice cladogram based on Larson and Dimmick (1993), that would great -->

==Phylogeny and evolution==
The origins and evolutionary relationships between the three main groups of amphibians ([[Caecilian|gymnophionan]]s, urodeles and [[anuran]]s) is a matter of debate. A 2005 molecular phylogeny, based on [[Ribosomal DNA|rDNA]] analysis, suggested that the first divergence between these three groups took place soon after they had branched from the [[lobe-finned fish]] in the [[Devonian]] (around 360 million years ago), and before the breakup of the supercontinent [[Pangaea]]. The briefness of this period, and the speed at which radiation took place, may help to account for the relative scarcity of amphibian fossils that appear to be closely related to [[lissamphibia]]ns.<ref>{{cite journal |author1=San Mauro, Diego |author2=Vences, Miguel |author3=Alcobendas, Marina |author4=Zardoya, Rafael |author5=Meyer, Axel |year=2005 |title=Initial diversification of living amphibians predated the breakup of Pangaea |journal=The American Naturalist |volume=165 |issue=5 |pages=590–599 |doi=10.1086/429523 |pmid=15795855 |s2cid=17021360 |url=https://pure.uva.nl/ws/files/3880726/39160_170248y.pdf }}</ref> More recent studies generally find more recent (Late [[Carboniferous]]<ref name=SM10>{{cite journal | last1 = San Mauro | first1 = D. | year = 2010 | title = A multilocus timescale for the origin of extant amphibians | journal = Molecular Phylogenetics and Evolution | volume = 56 | issue = 3| pages = 554–561 | doi = 10.1016/j.ympev.2010.04.019 | pmid=20399871| bibcode = 2010MolPE..56..554S }}</ref> to [[Permian]]<ref name=M&L07>{{cite journal | last1 = Marjanović | first1 = D. | last2 = Laurin | first2 = M. |name-list-style=vanc| year = 2007 | title = Fossils, molecules, divergence times, and the origin of lissamphibians | journal = Systematic Biology | volume = 56 | issue = 3| pages = 369–388 | doi = 10.1080/10635150701397635 | pmid=17520502| doi-access = free }}</ref>) age for the basalmost divergence among lissamphibians.
[[File:Karaurus sharovi skeleton 34.JPG|thumb|''[[Karaurus|Karaurus sharovi]]'']]
The earliest known salamander-line lissamphibian is ''[[Triassurus]]'' from the Middle-Late Triassic of Kyrgyzstan.<ref>{{Cite journal|last1=Schoch|first1=Rainer R.|last2=Werneburg|first2=Ralf|last3=Voigt|first3=Sebastian|date=2020-05-26|title=A Triassic stem-salamander from Kyrgyzstan and the origin of salamanders|journal=Proceedings of the National Academy of Sciences|language=en|volume=117|issue=21|pages=11584–11588|doi=10.1073/pnas.2001424117|issn=0027-8424|pmid=32393623|pmc=7261083|bibcode=2020PNAS..11711584S |doi-access=free}}</ref> Other fossil salamanders are known from the Middle-Late Jurassic of Eurasia, including ''[[Kokartus honorarius]]'' from the [[Middle Jurassic]] of Kyrgyzstan, two species of the apparently neotenic, aquatic ''[[Marmorerpeton]]'' from the Middle Jurassic of England and Scotland,<ref>{{cite journal | last1 = de Buffrénil | first1 = V. | last2 = Canoville | first2 = A. | last3 = Evans | first3 = S. E. | last4 = Laurin | first4 = M. |name-list-style=vanc| year = 2014 | title = Histological study of karaurids, the oldest known (stem) urodeles | journal = Historical Biology |volume=27 |issue=1 |pages=109–114 | doi = 10.1080/08912963.2013.869800| s2cid = 83557507 }}</ref><ref name="Jonesetal2022">{{Cite journal |last1=Jones |first1=Marc E. H. |last2=Benson |first2=Roger B. J. |last3=Skutschas |first3=Pavel |last4=Hill |first4=Lucy |last5=Panciroli |first5=Elsa |last6=Schmitt |first6=Armin D. |last7=Walsh |first7=Stig A. |last8=Evans |first8=Susan E. |date=2022-07-11 |title=Middle Jurassic fossils document an early stage in salamander evolution |journal=Proceedings of the National Academy of Sciences |volume=119 |issue=30 |pages=e2114100119 |doi=10.1073/pnas.2114100119 |issn=0027-8424|doi-access=free |pmid=35858401 |pmc=9335269 |bibcode=2022PNAS..11914100J }}</ref> and ''[[Karaurus]]'' from the Middle-Late Jurassic of Kazakhstan, resembled modern [[mole salamander]]s in morphology and probably had a similar burrowing lifestyle.<ref name="Naish2013" /> They looked like robust modern salamanders but lacked a number of anatomical features that characterise all modern salamanders.<ref name="Jonesetal2022">{{Cite journal |last1=Jones |first1=Marc E. H. |last2=Benson |first2=Roger B. J. |last3=Skutschas |first3=Pavel |last4=Hill |first4=Lucy |last5=Panciroli |first5=Elsa |last6=Schmitt |first6=Armin D. |last7=Walsh |first7=Stig A. |last8=Evans |first8=Susan E. |date=2022-07-11 |title=Middle Jurassic fossils document an early stage in salamander evolution |journal=Proceedings of the National Academy of Sciences |volume=119 |issue=30 |pages=e2114100119 |doi=10.1073/pnas.2114100119 |issn=0027-8424|doi-access=free |pmid=35858401 |pmc=9335269 |bibcode=2022PNAS..11914100J }}</ref><ref>{{cite journal | last1 = Marjanovic | first1 = D. | last2 = Laurin | first2 = M. |name-list-style=vanc| year = 2014 | title = An updated paleontological timetree of lissamphibians, with comments on the anatomy of Jurassic crown-group salamanders (Urodela) | journal = Historical Biology |volume=26 |issue=4 |pages=535–550| doi = 10.1080/08912963.2013.797972| bibcode = 2014HBio...26..535M | s2cid = 84581331 }}</ref>

The two groups of extant salamanders are the [[Cryptobranchoidea]] (which includes Asiatic and giant salamanders) and the [[Salamandroidea]] (which includes all other living salamanders), also known as Diadectosalamandroidei. Both groups are known from the Middle-Late Jurassic of China. the former being exemplified by ''[[Chunerpeton tianyiensis]]'', ''[[Pangerpeton sinensis]]'', ''[[Jeholotriton paradoxus]]'', ''[[Regalerpeton|Regalerpeton weichangensis]]'', ''[[Liaoxitriton|Liaoxitriton daohugouensis]]'' and ''[[Iridotriton|Iridotriton hechti]]'', and the latter by ''[[Beiyanerpeton jianpingensis]]''. By the [[Upper Cretaceous]], most or all of the living salamander families had probably appeared.<ref name="Naish2013" />

The following cladogram shows the relationships between salamander families based on the molecular analysis of Pyron and Wiens (2011).<ref>{{cite journal |author1=R. Alexander Pyron |author2=John J. Wiens | year = 2011 | title= A large-scale phylogeny of Amphibia including over 2800 species, and a revised classification of extant frogs, salamanders, and caecilians | journal = Molecular Phylogenetics and Evolution | volume = 61 | issue = 2 | pages = 543–583 | doi=10.1016/j.ympev.2011.06.012| pmid = 21723399 | doi-access = free |bibcode=2011MolPE..61..543A }}</ref> The position of the Sirenidae is disputed, but the position as sister to the Salamandroidea best fits with the molecular and fossil evidence.<ref name="Jonesetal2022">{{Cite journal |last1=Jones |first1=Marc E. H. |last2=Benson |first2=Roger B. J. |last3=Skutschas |first3=Pavel |last4=Hill |first4=Lucy |last5=Panciroli |first5=Elsa |last6=Schmitt |first6=Armin D. |last7=Walsh |first7=Stig A. |last8=Evans |first8=Susan E. |date=2022-07-11 |title=Middle Jurassic fossils document an early stage in salamander evolution |journal=Proceedings of the National Academy of Sciences |volume=119 |issue=30 |pages=e2114100119 |doi=10.1073/pnas.2114100119 |issn=0027-8424|doi-access=free |pmid=35858401 |pmc=9335269 |bibcode=2022PNAS..11914100J }}</ref><ref name=Naish2013/>

{{clade| style=font-size:80%;line-height:100%
|1={{Clade
   |1={{clade
      |label1=[[Cryptobranchoidea]]
      |1={{Clade
         |1=[[Cryptobranchidae]] (giant salamanders & hellbenders) [[File:Erpétologie générale, ou, Histoire naturelle complète des reptiles (Cryptobranchus alleganiensis).jpg|70 px]]
         |2=[[Hynobiidae]] (Asiatic salamanders) [[File:Erpétologie générale, ou, Histoire naturelle complète des reptiles (Onychodactylus japonicus).jpg|70 px]]
         }}
       }}
   |2={{clade
      |label1=[[Sirenoidea]]
      |1=[[Sirenidae]] (sirens) [[File:Siren lacertina (white background).jpg|70 px]]
      |label2=[[Salamandroidea]] <!--[[Diadectosalamandroidei]] (synonym)-->
      |2={{Clade
         |1={{clade
            |label1=[[Treptobranchia]]
            |1={{Clade
               |1=[[Salamandridae]] (true salamanders & newts) [[File:Salamandra salamandra (white background).jpg|70 px]]
               |label2=
               |2={{Clade
                  |1=[[Ambystomatidae]] (axolotls & tiger salamanders) [[File:Erpétologie générale, ou, Histoire naturelle complète des reptiles (Ambystoma mexicanum).jpg|70 px]]
                  |2=[[Dicamptodontidae]] (Pacific giant salamanders)
               }}
               }}
            }}
         |2={{Clade
            |1=[[Proteidae]] (olms & waterdogs) [[File:Proteus anguinus - (white background).jpg|70 px]]
            |label2=[[Plethosalamandroidei]]
            |2={{Clade
               |1=[[Rhyacotritonidae]] (torrent salamanders)
               |label2=[[Xenosalamandroidei]]
               |2={{Clade
                  |1=[[Amphiumidae]] (amphiumas) [[File:Descriptiones et icones amphibiorum (Amphiuma means).jpg|70 px]]
                  |2=[[Plethodontidae]] (lungless salamanders) [[File:Erpétologie générale, ou, Histoire naturelle complète des reptiles (Bolitoglossa mexicana).jpg|70 px]]
                  }}
               }}
            }}
         }}
      }}
   }}
}}

== Genome and genetics ==
Salamanders possess gigantic genomes, spanning the range from 14 Gb to 120 Gb<ref>{{Cite journal|last1=Sun|first1=Cheng|last2=Shepard|first2=Donald B.|last3=Chong|first3=Rebecca A.|last4=López Arriaza|first4=José|last5=Hall|first5=Kathryn|last6=Castoe|first6=Todd A.|last7=Feschotte|first7=Cédric|last8=Pollock|first8=David D.|last9=Mueller|first9=Rachel Lockridge|date=2012-01-01|title=LTR Retrotransposons Contribute to Genomic Gigantism in Plethodontid Salamanders|journal=Genome Biology and Evolution|language=en|volume=4|issue=2|pages=168–183|doi=10.1093/gbe/evr139|pmid=22200636|pmc=3318908}}</ref> (the [[human genome]] is 3.2 Gb long). The genomes of ''[[Pleurodeles waltl]]'' (20 Gb) and [[Axolotl|''Ambystoma mexicanum'']] (32 Gb) have been sequenced.<ref>{{Cite journal|last1=Elewa|first1=Ahmed|last2=Wang|first2=Heng|last3=Talavera-López|first3=Carlos|last4=Joven|first4=Alberto|last5=Brito|first5=Gonçalo|last6=Kumar|first6=Anoop|last7=Hameed|first7=L. Shahul|last8=Penrad-Mobayed|first8=May|last9=Yao|first9=Zeyu|date=2017-12-22|title=Reading and editing the Pleurodeles waltl genome reveals novel features of tetrapod regeneration|journal=Nature Communications|language=En|volume=8|issue=1|pages=2286|doi=10.1038/s41467-017-01964-9|pmid=29273779|pmc=5741667|bibcode=2017NatCo...8.2286E|issn=2041-1723}}</ref><ref>{{Cite journal|title=The axolotl genome and the evolution of key tissue formation regulators|journal=Nature|volume=554|issue=7690|pages=50–55|doi=10.1038/nature25458|pmid=29364872|year=2018|last1=Nowoshilow|first1=Sergej|last2=Schloissnig|first2=Siegfried|last3=Fei|first3=Ji-Feng|last4=Dahl|first4=Andreas|last5=Pang|first5=Andy W. C.|last6=Pippel|first6=Martin|last7=Winkler|first7=Sylke|last8=Hastie|first8=Alex R.|last9=Young|first9=George|last10=Roscito|first10=Juliana G.|last11=Falcon|first11=Francisco|last12=Knapp|first12=Dunja|last13=Powell|first13=Sean|last14=Cruz|first14=Alfredo|last15=Cao|first15=Han|last16=Habermann|first16=Bianca|last17=Hiller|first17=Michael|last18=Tanaka|first18=Elly M.|last19=Myers|first19=Eugene W.|bibcode=2018Natur.554...50N|doi-access=free|hdl=21.11116/0000-0003-F659-4|hdl-access=free}}</ref>

Their giant genomes have strongly affected their physiology. This includes their skeletal and circulatory systems, and have led to a simplified brain, weak heart and slow metabolism.<ref>{{cite journal |last1=Sun |first1=C. |last2=Mueller |first2=R. L. |title=Hellbender Genome Sequences Shed Light on Genomic Expansion at the Base of Crown Salamanders |journal=Genome Biology and Evolution |date=17 July 2014 |volume=6 |issue=7 |pages=1818–1829 |doi=10.1093/gbe/evu143 |pmid=25115007 |pmc=4122941 }}</ref> The cell mechanisms that prevents transposons to accumulate seems to be partially defect in salamanders. Some species with the largest genomes have lost the ability to go through metamorphosis. The development of the body is slower than its growth compared to their ancestors, and stops at a certain age, leaving them with embryonic traits. The salamander tissues contain cells that differentiates slowly, weakly, or not at all, due to intron delay, which gives them regenerative properties, which includes regenerating parts of the face and eye, lungs, liver, heart, and even the spinal cord and brain, and they have been described as "walking bags of stem cells".<ref>{{cite journal |last1=Sessions |first1=Stanley K. |last2=Wake |first2=David B. |title=Forever young: Linking regeneration and genome size in salamanders |journal=Developmental Dynamics |date=June 2021 |volume=250 |issue=6 |pages=768–778 |doi=10.1002/dvdy.279 |pmid=33320991 }}</ref><ref>{{cite journal |last1=Fox |first1=Douglas |title=Junk DNA Deforms Salamander Bodies |journal=Scientific American |date=February 2022 |volume=326 |issue=2 |page=40 |url=https://www.scientificamerican.com/video/junk-dna-deforms-salamander-bodies/ }}</ref><ref>{{cite news |last1=Fox |first1=Douglas |title=Living mysteries: This critter has 38 times more DNA than you do |url=https://www.snexplores.org/article/salamander-genome-size-aging-dna-transposons |work=Science News Explores |date=29 September 2022 }}</ref> Research has also shown that they do not develop typical signs of aging and do not accumulate age-related diseases like cancer.<ref>[https://www.mpi-cbg.de/news-outreach/news-media/article/benefits-of-zombie-cells-senescent-cells-aid-regeneration-in-salamanders Benefits of “Zombie” Cells: Senescent Cells Aid Regeneration in Salamanders]</ref>

==In human society==

===Myth and legend===
{{Main|Cultural depictions of salamanders}}
[[File:A salamander unharmed in the fire.jpg|thumb|left|A salamander unharmed in the fire, 1350]]

Legends have developed around the salamander over the centuries, many related to fire. This connection likely originates from the tendency of many salamanders to dwell inside rotting logs. When the log was placed into a fire, the salamander would attempt to escape, lending credence to the belief that salamanders were created from flames.<ref name="Ashcroft">{{cite book | last= Ashcroft| first= Frances | title = Life at the Extremes: The Science of Survival | url= https://archive.org/details/lifeatextremes0000ashc| url-access= registration| publisher = University of California Press| year = 2002| page = [https://archive.org/details/lifeatextremes0000ashc/page/112 112]| isbn = 978-0-520-22234-2}}</ref>

The association of the salamander with fire appeared first in Antiquity with [[Aristotle]] (''History of Animals'' 5, 17) and with [[Pliny the Elder]] writing in his ''[[Natural History (Pliny)|Natural History]] '' (10, 86) that "A salamander is so cold that it puts out fire on contact. It vomits from its mouth a milky liquid; if this liquid touches any part of the human body, it causes all the hair to fall off, and the skin to change color and break out in a rash."<ref>{{cite book | title=Natural History | author=Pliny the Elder | author-link=Pliny the Elder | year=c. 100 | pages=Book 10, 86 | url=http://bestiary.ca/beasts/beast276.htm | access-date=2014-01-08 | archive-date=2008-10-18 | archive-url=https://web.archive.org/web/20081018032957/http://bestiary.ca/beasts/beast276.htm | url-status=live }}</ref> The ability to put out fire is repeated by [[Saint Augustine]] in the fifth century and [[Isidore of Seville]] in the seventh century.<ref>{{cite book | title=City of God | author=Saint Augustine | year=c. 500 | pages=Book 21, 4}}</ref><ref>{{cite book | url=http://bestiary.ca/beasts/beast276.htm | title=Etymologies | author=Isidore of Seville | year=c. 700 | pages=Book 12, 4:36 | access-date=2014-01-08 | archive-date=2008-10-18 | archive-url=https://web.archive.org/web/20081018032957/http://bestiary.ca/beasts/beast276.htm | url-status=live }}</ref><!--(Salamander and Fire) ... mentioned in the [[Talmud]] and by [[Leonardo da Vinci]], [[Paracelsus]], [[Conrad Lycosthenes]], [[Benvenuto Cellini]] and [[Jean-Jacques Rousseau]], and more recently by [[Victor Hugo]], [[Ray Bradbury]], [[David Weber]] and [[J. K. Rowling]]. Obviously each one of these would need a citation-->

[[File:Hanagami Danjo no jo Arakage fighting a giant salamander.jpg|thumbnail|upright|''[[Ukiyo-e]]'' print by [[Utagawa Kuniyoshi]] (1797–1861) depicting a giant salamander being stabbed by the [[samurai]] Hanagami Danjō no jō Arakage]]

The mythical ruler [[Prester John]] supposedly had a robe made from alleged salamander hair, in fact [[asbestos]] fibre, already known by ancient Greece and Rome (the ''linum vivum'' of [[Pliny the Elder]] ''[[Natural History (Pliny)|Naturalis historia]]'', 19, 4).<ref>{{cite journal | doi=10.1179/004049603235001454 | title=Salamander's Wool: The Historical Evidence for Textiles Woven with Asbestos Fibre | date=2003 | last1=Browne | first1=Clare | journal=Textile History | volume=34 | pages=64–73 | s2cid=191599472 }}</ref> The "Emperor of India" possessed a suit made from a thousand skins; [[Pope Alexander III]] had a tunic which he valued highly and [[William Caxton]] (1481) wrote: "This Salemandre berithe wulle, of which is made cloth and gyrdles that may not brenne in the fyre."<ref name= White>{{cite book | last= White| first= T. H. | author-link=T. H. White | title=The Book of Beasts: Being a Translation From a Latin Bestiary of the Twelfth Century | year=1992 |orig-year=1954| pages= 183–184 | publisher=[[Alan Sutton]] |isbn=978-0-7509-0206-9}}</ref> The salamander was said to be so toxic that by twining around a tree, it could poison the fruit and so kill any who ate them and by falling into a well, could kill all who drank from it.<ref name="White"/>

Wealthy [[Persians]] amazed guests by cleaning a cloth by exposing it to [[fire]]. For example, according to [[Muhammad ibn Jarir al-Tabari|Tabari]], one of the curious items belonging to [[Khosrow II]] Parviz, the great [[Sassanian]] king (r. 590–628), was a napkin ({{langx|fa|منديل}}) that he cleaned simply by throwing it into fire. Such cloth is believed to have been made of asbestos imported over the [[Hindu Kush]].<ref>New Encyclopædia Britannica (2003), vol. 6, p. 843</ref> According to [[Biruni#ref-16|Biruni]] in his book ''Gems'', any cloths made of asbestos ({{langx|fa|آذرشست}}, ''āzarshost'') were called ''shostakeh'' ({{langx|fa|شستكه}}).<ref>[[Dehkhoda Dictionary|Dehkhoda Persian Dictionary]]</ref> Some Persians believed the fiber was the fur of an animal called the ''[[Salamander (legendary creature)|samandar]]'' ({{langx|fa|سمندر}}), which lived in fire and died when exposed to water;<ref name="Ucalgary">{{cite web|url=http://www.iras.ucalgary.ca/~volk/sylvia/Asbestos.htm|title=University of Calgary|date=30 September 2001|publisher=Iras.ucalgary.ca|archive-url=https://web.archive.org/web/20091105005311/http://www.iras.ucalgary.ca/~volk/sylvia/Asbestos.htm|archive-date=5 November 2009|access-date=12 January 2010}}</ref><ref>[http://environmentalchemistry.com/yogi/environmental/asbestoshistory2004.html A Brief History of Asbestos Use and Associated Health Risks] EnvironmentalChemistry.com website</ref> this may be where the belief originated that the salamander could tolerate fire.<ref>{{Cite magazine|url=https://www.wired.com/2014/08/fantastically-wrong-homicidal-salamander/|title=Fantastically Wrong: The Legend of the Homicidal Fire-Proof Salamander|magazine=WIRED|language=en-US|access-date=2016-05-03}}</ref> [[Charlemagne]], the first [[Holy Roman Emperor]] (800–814), is also said to have possessed such a tablecloth.<ref name="TIME1926">{{Cite magazine|date=29 November 1926|title=Science: Asbestos|url=http://www.time.com/time/magazine/article/0,9171,729732,00.html|magazine=[[Time (magazine)|Time]]|archive-url=https://web.archive.org/web/20110131223759/http://www.time.com/time/magazine/article/0%2C9171%2C729732%2C00.html|archive-date=31 January 2011|access-date=11 January 2011}}</ref>

[[Marco Polo]] recounts having been shown, in a place he calls ''Ghinghin talas'', "a good vein from which the cloth which we call of salamander, which cannot be burnt if it is thrown into the fire, is made&nbsp;..."<ref name="PoloMoule1938">{{cite book|url=https://archive.org/stream/descriptionofwor01polo#page/156/mode/2up/search/salamander|title=Marco Polo: the Description of the World: A.C. Moule & Paul Pelliot|last1=Polo|first1=Marco|author2=A C. Moule|author3=Paul Pelliot|publisher=G. Routledge & Sons|year=1938|pages=156–57|access-date=31 January 2013}}</ref>

In his [[autobiography]], [[Benvenuto Cellini]] relates:

{{blockquote|When I was about five, my father was sitting alone in one of our small rooms, singing and playing his viol. Some washing had just been done there and a good log fire was still burning. It was very cold, and he had drawn near the fire. Then, as he was looking at the flames, his eye fell on a little animal, like a lizard, that was running around merrily in the very hottest part of the fire. Suddenly realizing what it was, he called my sister and myself and showed it to us. And then he gave me such a violent box on the ears that I screamed and burst into tears. At this he calmed me as kindly as he could and said: 'My dear little boy, I didn't hit you because you had done wrong. I only did it so that you will never forget that the lizard you saw in the fire is a salamander, and as far as we know for certain no one has ever seen one before.'<ref>{{Cite book|last=Cellini|first=Benvenuto|title=The Autobiography of Benvenuto Cellini|publisher=Penguin Books|year=1998|isbn=0140447180|location=England|pages=34}}</ref>}}

The Japanese giant salamander has been the subject of legend and artwork in Japan (e.g. the ''[[ukiyo-e]]'' work by [[Utagawa Kuniyoshi]]). The well-known Japanese mythological creature known as the [[Kappa (folklore)|''kappa'']] may be inspired by this salamander.<ref>{{cite episode | title = River Monsters | series = Programme 6, Series 3 | credits = Director: Duncan Chard | network = [[ITV (TV network)|ITV]] | station = [[ITV1]] | airdate = 2012-02-14 }}</ref>

===Medical research===
Salamanders' [[limb regeneration]] has long been the focus of interest among scientists. The first extensive cell-level study was by Vincenzo Colucci in 1886.<ref name=Holland>{{citation |title=Vicenzo Colucci's 1886 memoir, Intorno alla rigenerazione degli arti e della coda nei tritoni, annotated and translated into English as: Concerning regeneration of the limbs and tail in salamanders | first=Nicholas | last=Holland | journal=The European Zoological Journal | volume=88 | year=2021| pages=837–890 | doi=10.1080/24750263.2021.1943549 | doi-access=free }}</ref> Researchers have been trying to find out the conditions required for the growth of new limbs and hope that such [[Regenerative medicine|regeneration]] could be replicated in humans using [[stem cell]]s. [[Axolotl]]s have been used in research and have been genetically engineered so that a [[fluorescent]] protein is present in cells in the leg, enabling the cell division process to be tracked under the microscope. It seems that after the loss of a limb, cells draw together to form a clump known as a [[blastema]]. This superficially appears undifferentiated, but cells that originated in the skin later develop into new skin, muscle cells into new muscle and cartilage cells into new cartilage. It is only the cells from just beneath the surface of the skin that are [[pluripotent]] and able to develop into any type of cell.<ref>{{cite magazine|title=Salamander discovery could lead to human limb regeneration|magazine=Wired|url=https://www.wired.com/wiredscience/2009/07/regeneration/|last=Keim|first=Brandon |date=2009-07-01 |access-date=2010-05-07}}</ref> Researchers from the [[Australian Regenerative Medicine Institute]] have found that when [[macrophages]] were removed, salamanders lost their ability to regenerate and instead formed scar tissue. If the processes involved in forming new tissue can be reverse engineered into humans, it may be possible to heal injuries of the spinal cord or brain, repair damaged organs and reduce scarring and [[fibrosis]] after surgery.<ref name=ScienceDaily>{{cite web |title=Do salamanders' immune systems hold the key to regeneration? |url=https://www.sciencedaily.com/releases/2013/05/130520163727.htm |website=ScienceDaily |access-date=2013-05-21 |archive-date=2013-12-06 |archive-url=https://web.archive.org/web/20131206013619/http://www.sciencedaily.com/releases/2013/05/130520163727.htm |url-status=live }}</ref>

The spotted salamander (Amblystoma maculatum) lives in a symbiotic relationship with a green algae known as Oophila amblystomatis. The algal cells make their way into tissue cells throughout the embryo's body and appears to avoid rejection by activating genes which suppress the embryo's immune response. A mechanism that could be used in treatment for autoimmune diseases in humans.<ref>[https://newatlas.com/science/symbiotic-salamander-embryo-algae-drugs/ Symbiotic salamander/algae relationship may inspire new drugs]</ref>

===Brandy===
A 1995 article in the Slovenian weekly magazine ''[[Mladina]]'' publicized salamander brandy, a [[liquor]] supposedly indigenous to [[Slovenia]]. It was said to combine [[hallucinogenic]] with [[aphrodisiac]] effects and is made by putting several live salamanders in a barrel of fermenting fruit. Stimulated by the alcohol, they secrete toxic mucus in defense and eventually die. Besides causing hallucinations, the [[neurotoxin]]s present in the brew were said to cause extreme [[sexual arousal]].<ref>{{cite news |title=Mind-Bending Hallucinogenic Drinks |author=Goldsmith, Richard |url=https://www.foxnews.com/food-drink/mind-bending-hallucinogenic-drinks |newspaper=Fox News |date=2010-06-11 |access-date=2014-01-02 |archive-date=2014-12-05 |archive-url=https://web.archive.org/web/20141205172850/http://www.foxnews.com/leisure/2010/06/10/hallucinogenic-drinks/ |url-status=live }}</ref>

Later research by Slovenian anthropologist Miha Kozorog ([[University of Ljubljana]]) paints a very different picture—Salamander in brandy appears to have been traditionally seen as an [[adulterant]], one which caused ill health. It was also used as a term of slander.<ref>{{cite journal|last=Kozorog|first=Miha|title=Salamander Brandy: 'A Psychedelic Drink' Between Media Myth and Practice of Home Alcohol Distillation in Slovenia|journal=Anthropology of East Europe Review|year=2003|volume=21|issue=1|pages=63–71|url=http://scholarworks.iu.edu/journals/index.php/aeer/article/view/364|access-date=2014-03-22|archive-date=2014-03-31|archive-url=https://web.archive.org/web/20140331130641/http://scholarworks.iu.edu/journals/index.php/aeer/article/view/364|url-status=live}}</ref>

==References==
=== Citations ===
{{Reflist}}

===Cited texts===
* {{cite book |editor1=Cogger, H. G. |editor2=[[Richard G. Zweifel|Zweifel, R. G.]] |year=1998 |title=Encyclopedia of Reptiles and Amphibians |edition=2nd |publisher=Academic Press |isbn=978-0-12-178560-4}}
* {{cite book | author=Cott, Hugh B. | year=1940 | title=Adaptive Coloration in Animals | publisher=Oxford University Press}}
* {{cite book |last1=Dorit |first1=R. L. |last2=Walker |first2=W. F. |last3=Barnes |first3=R. D. |year=1991 |title=Zoology |url=https://archive.org/details/zoology0000dori |url-access=registration |publisher=Saunders College Publishing |isbn=978-0-03-030504-7 }}
* {{cite book |author=Kardong, Kenneth V. |year=2009 |title=Vertebrates: Comparative Anatomy, Function, Evolution |edition=5th |publisher=McGraw-Hill |isbn=978-0-07-304058-5}}
* {{cite book |last1=Stebbins |first1=Robert C. |author-link1=Robert C. Stebbins|last2=Cohen |first2=Nathan W. |year=1995 |title=A Natural History of Amphibians |publisher=Princeton University Press |isbn=978-0-691-03281-8 |url=https://books.google.com/books?id=0v47ou53yVsC&q=Caudata+Urodela&pg=PR11 }}

==External links==
{{Wikispecies|Urodela}}
{{Commons category|Caudata}}
* [http://tolweb.org/Caudata/14939 Tree of Life: Caudata]
* [http://theinformationarchives.com/Salamander/ Salamander Gallery]
* [http://www.caudata.org/cc Caudata Culture]
* [https://www.fhwa.dot.gov/environment/critter_crossings/salamand.cfm Critter Crossings: Salamander Tunnels] at [[U.S. Department of Transportation]]
* [https://web.archive.org/web/20130728184525/http://photos.archeozoo.org/picture/2398-urodela/category/54-amphibiens_langen_amphibians_lang_langes_anfibios_lang_?lang=en_UK ArchéoZooThèque : Urodele skeleton drawing] : available in vector, image and PDF formats

{{Lissamphibia}}
{{Amphibians}}
{{Caudata}}
{{Taxonbar|from=Q53663}}
{{Authority control}}
{{portalbar|Amphibians}}

[[Category:Salamanders| ]]
[[Category:Aposematic animals]]
[[Category:Articles containing video clips]]
[[Category:Extant Late Jurassic first appearances]]
[[Category:Taxa named by André Marie Constant Duméril]]