View source for Newt

{{Automatic taxobox
| name = Newt
| fossil_range = {{Geological range|Late Cretaceous|Recent|ref=<ref name="ZhangPapenfuss2008">{{cite journal|last1=Zhang|first1=Peng|last2=Papenfuss|first2=Theodore J.|last3=Wake|first3=Marvalee H.|last4=Qu|first4=Lianghu|last5=Wake|first5=David B.|title=Phylogeny and biogeography of the family Salamandridae (Amphibia: Caudata) inferred from complete mitochondrial genomes|journal=Molecular Phylogenetics and Evolution|volume=49|issue=2|year=2008|pages=586–597|issn=1055-7903|doi=10.1016/j.ympev.2008.08.020|url=https://bsp.berkeley.edu/labs/mwake/papers/206.pdf|pmid=18801447|access-date=2018-05-28|archive-date=2017-02-02|archive-url=https://web.archive.org/web/20170202004738/https://bsp.berkeley.edu/labs/mwake/papers/206.pdf|url-status=dead}}</ref>
}}
| image =
| image_caption = [[Kaiser's spotted newt]]
| taxon = Pleurodelinae
| subdivision_ranks = Genera
| subdivision = 14–17 living and six [[fossil]] genera
}}
[[File:Notophthalmus viridescensPCCA20040816-3983A.jpg|thumb|225px|A red-spotted newt (eft stage). <br/>The bright [[Mimicry#Warning coloration|aposematic]] colouration warns predators of its highly toxic skin.]]

'''Newts''' or ''efts'' are small [[amphibia]]. They are in a [[subfamily]] of the [[Salamandridae|salamanders]]. They are found in [[North America]], [[Europe]], and North [[Asia]].

== Life cycle ==
Females lay [[Egg (biology)|eggs]] and leave them. [[Tadpole]]s are [[Birth|born]] from those eggs.

Newts have three life stages. First as a tiny [[aquatic]] [[larva]], which gradually undergoes [[metamorphosis]]. Then they leave the water for a year as a juvenile called an ''eft''. They go back in the water to breed as adults.

In some species the adults stay in water for the rest of their lives. Others are land-based, but return to water each year to breed.

== Defences ==
Many newts produce [[toxin]]s in their skin secretions as a [[defence against predators]]. They have [[wikt:bright|bright]] skin colours as a warning to other animals.

''Taricha'' newts of western North America are particularly toxic; the [[rough-skinned newt]] ''Taricha granulosa'' of the Pacific Northwest produces more than enough [[tetrodotoxin]] to kill an adult human. Recently, a 29-year-old man in Coos Bay, [[Oregon]], who had been drinking heavily, swallowed a rough-skin newt for a dare; he died later that day despite hospital treatment.<ref name="caudata"/>

Most newts can be safely handled, provided that the toxins they produce are not ingested or allowed to come in contact with [[mucous membrane]]s, or breaks in the skin.<ref name="caudata">see [http://www.caudata.org/cc/articles/toxin2.shtml caudata.org] {{Webarchive|url=https://web.archive.org/web/20130531031806/http://www.caudata.org/cc/articles/toxin2.shtml |date=2013-05-31 }} Accessed 2007-11-28</ref> After handling, proper hand-washing techniques should be followed due to the risk from the toxins they produce and bacteria they carry, such as [[salmonella]].<ref>[https://web.archive.org/web/20040618015311/http://www.metrokc.gov/health/prevcont/salmonellosis-reptiles.htm Salmonellosis - Reptiles and Amphibians] Accessed 2007-11-28</ref><ref>[https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5249a3.htm CDC MMWR: Reptile-Associated Salmonellosis: Selected States, 1998-2002] Accessed 2007-11-28</ref> It is illegal to handle or disturb [[great crested newt]]s in the [[UK]] without a licence.<ref name="bbc.co.uk Factfile 479">[http://www.bbc.co.uk/nature/wildfacts/factfiles/479.shtml bbc.co.uk Factfile 479] {{Webarchive|url=https://archive.today/20120524210208/www.bbc.co.uk/nature/wildfacts/factfiles/479.shtml |date=2012-05-24 }} Accessed 2007-11-28</ref>

== Are newts a related group? ==
The term "newt" has traditionally been used as a functional term for salamanders living in water, and not a [[Biological classification|systematic unit]]. The relationship between the genera has been uncertain, though they may be a [[clade|natural systematic unit]]. Newer molecular analysis tend to suggest they actually do form a [[clade]].<ref>Titus T.A. & A. Larson 1995. A molecular phylogenetic perspective on the evolutionary radiation of the salamander family Salamandridae. ''Systematic Biology'' '''44''', 125-151.</ref><ref name=Steinfartz>Steinfartz S. S. Vicario, J.W. Arntzen & A. Caccone 2006. A Bayesian approach on molecules and behavior: reconsidering phylogenetic and evolutionary patterns of the Salamandridae with emphasis on ''Triturus'' newts. ''Journal of Experimental Zoology'' Part B: Molecular and Developmental Evolution</ref><ref>Weisrock D.W. ''et al.'' 2006. A molecular assessment of phylogenetic relationships and lineage accumulation rates within the family Salamandridae (Amphibia, Caudata). ''Molecular Phylogenetics and Evolution'' '''41''', 368-383.</ref>
Newts only appear in one subfamily of salamanders, the Pleurodelinae (of the family [[Salamandridae]]).<ref>Larson A, Wake D. & Devitt T. 2007. Salamandridae, newts and "true salamanders". [[Tree of Life]] on-line project [http://tolweb.org/Salamandridae] {{Webarchive|url=https://web.archive.org/web/20160304043646/http://tolweb.org/Salamandridae |date=2016-03-04 }}</ref>
Some genera occasionally listed as Pleurodelinae are not newts (''[[Salamandrina]]'' and ''[[Euproctus]]'').

== References ==
{{wikispecies|Salamandridae}}
{{Reflist}}

[[Category:Newts| ]]