Editing Amplexus (section)

==Amphibians==
[[File:Mating_pair_of_common_frogs_in_amplexus.jpg|thumb|right|European [[common frog]]]]
[[File:Amplexus Bufo bufo 2010-03-29.jpg|thumb|European [[common toad]] (''[[Bufo bufo]]'').]]
[[File:Common toad Bufo bufo multiple amplexus mating ball.jpg|thumb|[[Common toad]] [[mating ball]] (multiple amplexus).]]

[[File:American toads during amplexus.jpg|thumb|American toads during amplexus in Missouri]]

[[File:Red-eyed tree frogs mating.JPG|thumb|[[Agalychnis callidryas|Red-eyed tree frog]] (''[[Agalychnis callidryas]]''), [[Costa Rica]]]]

===Anurans===
Amplexus chiefly occurs aquatically, but some terrestrial [[Frog|anurans]] (frogs and toads) like the [[disc-tongued frog]]s ([[Discoglossidae]]) perform amplexus on land. In crown-group anurans, like the true frogs ([[Ranidae]]), the [[tree frog]]s (Hylidae), and the true toads ([[Bufonidae]]), amplexus is axillary (in the armpits). Other anurans (the [[Archaeobatrachia]], [[Sooglossidae]] and [[Myobatrachidae]]), show the ancestral state which is inguinal or lumbar amplexus (abdominal, in front of the hindlegs). Some species show cephalic amplexus where the head of the female is held while others show complete lack of amplexus.<ref name=Duellman&Trueb/> Additionally, anurans species have been observed to engage in multiple amplexus, which can also be referred to as a mating ball, as many toads attach themselves to a female trying to initiate amplexus.<ref name=":8">{{Cite journal|last1=Lod|first1=Thierry|last2=Lesbarr|first2=David|date=2004|title=Multiple paternity in Rana dalmatina, a monogamous territorial breeding anuran|journal=Naturwissenschaften|volume=91|issue=1|pages=44–47|doi=10.1007/s00114-003-0491-7|pmid=14740104|issn=0028-1042|bibcode=2004NW.....91...44L|s2cid=21612515}}</ref> However, multiple amplexus is not common among anurans, which could indicate that the costs associated with multiple amplexus are higher than the advantages associated with it.<ref name=":8" /> For female anurans, the idea of multiple amplexus would probably be more advantageous, because mating with more than one male would increase fertilization chances or increase offspring genetic diversity.<ref name=":8" /> Multiple amplexus would typically be common in explosive breeding amphibians, when there is a larger number of adults ready to breed at a breeding site in a short period of time.<ref name=":02" /> When this occurs female amphibians are viewed as a very important resource for males, as there are typically more males present than females, thus leading to more chances for multiple amplexus to occur.<ref name=":02" />

In most anurans, the males deposit sperm onto the eggs as they are being laid, however males of the genus ''[[Ascaphus]]'' possess an [[intromittent organ]], unique among anurans, for internal fertilization.  Internal fertilization does occur in a few other genera, including ''[[Nectophrynoides]]'', ''[[Mertensophryne]]'', and ''[[Eleutherodactylus]]''.<ref name=Duellman&Trueb>Duellman, W. E. and L. Trueb. 1986. Biology of Amphibians. New York: McGraw-Hill Publishing Company.</ref><ref>Linzey, D. 2001. Vertebrate Biology, McGraw Hill Publishers, New York.</ref>

===Newts===
In the case of [[newt]]s, the process of amplexus is often observed soon after the newts become seasonally active. In the Western USA, for example, this time is typically soon after the onset of the winter rainy season, when [[intermittent stream]]s and [[vernal pools]] become available as a breeding habitat.  The [[rough-skinned newt]] is a specific widespread example of a newt in the western USA that can be observed in quiet stream pools and shallow ponds engaging in amplexus.<ref>C. Michael Hogan (2008) ''[http://www.globaltwitcher.com/artspec_information.asp?thingid=43182 Rough-skinned Newt (Taricha granulosa)] {{webarchive|url=https://web.archive.org/web/20090527153302/http://www.globaltwitcher.com/artspec_information.asp?thingid=43182 |date=2009-05-27 }}'', Globaltwitcher, ed. N. Stromberg</ref> During amplexus in newts, males will typically show the behaviour of tail fanning and chin rubbing which is thought to prompt the mating receptivity of the female newt.<ref name=":11">{{Cite journal|last=Able|first=David J.|date=1999-11-04|title=Scramble competition selects for greater tailfin size in male red-spotted newts (Amphibia: Salamandridae)|journal=Behavioral Ecology and Sociobiology|volume=46|issue=6|pages=423–428|doi=10.1007/s002650050638|bibcode=1999BEcoS..46..423A |s2cid=34638425|issn=0340-5443}}</ref> Studies have shown that male newts who have deeper tail-fins have better control of females during amplexus and are also more successful in catching the females for amplexus.<ref name=":11" /> Additionally, it has been found that the probability of a male newt who has a deeper tail-fin to achieve amplexus is greater than those newts who do not contain a deeper tail-fin, as male newts tend to use their tails during male-male competition.<ref name=":11" /> When a male newt, who is unpaired, encounters a female and male newt engaged in amplexus, the unpaired newt will try to displace the paired male newt by using wrestling tactics.<ref name=":9">{{Cite journal|last=Verrell|first=Paul A.|date=1986|title=Wrestling in the red-spotted newt (Notophthalmus viridescens): resource value and contestant asymmetry determine contest duration and outcome|journal=Animal Behaviour|volume=34|issue=2|pages=398–402|doi=10.1016/s0003-3472(86)80108-7|s2cid=53183312|issn=0003-3472}}</ref> A study examining the wrestling behaviour of newts found that of the observed wrestling encounters, 90% were "won" by the paired male, meaning he would retain the female newt.<ref name=":9" /> The study found that the invading unpaired newt rarely successfully displaces the paired male newt,  engaged in amplexus.<ref name=":9" />