Editing Amphibian (section)

== Feeding and diet ==
[[File:Pacific brown salamander eating a worm.jpg|thumb|alt=Northwestern salamander|[[Northwestern salamander]] <br/>(''Ambystoma gracile'') eating a worm]]
With a few exceptions, adult amphibians are [[Predation|predators]], feeding on virtually anything that moves that they can swallow. The diet mostly consists of small prey that do not move too fast such as beetles, caterpillars, earthworms and spiders. The sirens (''[[Siren (genus)|Siren spp.]]'') often ingest aquatic plant material with the invertebrates on which they feed<ref>{{cite web |url=http://animaldiversity.ummz.umich.edu/site/accounts/information/Siren_intermedia.html |title=''Siren intermedia'': Lesser Siren |author=Gabbard, Jesse |year=2000 |work=Animal Diversity Web |publisher=University of Michigan Museum of Zoology |access-date=August 11, 2012 |archive-date=January 2, 2010 |archive-url=https://web.archive.org/web/20100102053811/http://animaldiversity.ummz.umich.edu/site/accounts/information/Siren_intermedia.html |url-status=live }}</ref> and a Brazilian tree frog (''[[Xenohyla truncata]]'') includes a large quantity of fruit in its diet.<ref>{{cite journal |author1=Da Silva, H. R. |author2=De Britto-Pereira, M. C. |year=2006 |title=How much fruit do fruit-eating frogs eat? An investigation on the diet of ''Xenohyla truncata'' (Lissamphibia: Anura: Hylidae) |journal=Journal of Zoology |volume=270 |issue=4 |pages=692–698 |doi=10.1111/j.1469-7998.2006.00192.x |url=https://www.academia.edu/26660305 |access-date=November 10, 2016 |archive-date=June 23, 2019 |archive-url=https://web.archive.org/web/20190623022254/https://www.academia.edu/26660305/How_much_fruit_do_fruit-eating_frogs_eat_An_investigation_on_the_diet_of_Xenohyla_truncata_Lissamphibia_Anura_Hylidae_ |url-status=live }}</ref> The [[Mexican burrowing toad]] (''Rhinophrynus dorsalis'') has a specially adapted tongue for picking up ants and termites. It projects it with the tip foremost whereas other frogs flick out the rear part first, their tongues being hinged at the front.<ref>{{cite journal |author1=Trueb, Linda |author-link1=Linda Trueb|author2=Gans, Carl |year=1983 |title=Feeding specializations of the Mexican burrowing toad, ''Rhinophrynus dorsalis'' (Anura: Rhinophrynidae) |journal=Journal of Zoology |volume=199 |issue=2 |pages=189–208 |doi=10.1111/j.1469-7998.1983.tb02090.x |url=https://deepblue.lib.umich.edu/bitstream/2027.42/74489/1/j.1469-7998.1983.tb02090.x.pdf |hdl=2027.42/74489 |hdl-access=free |access-date=August 27, 2019 |archive-date=July 27, 2020 |archive-url=https://web.archive.org/web/20200727223533/https://deepblue.lib.umich.edu/bitstream/handle/2027.42/74489/j.1469-7998.1983.tb02090.x.pdf?sequence=1 |url-status=live }}</ref>

Food is mostly selected by sight, even in conditions of dim light. Movement of the prey triggers a feeding response. Frogs have been caught on fish hooks baited with red flannel and [[Rana clamitans|green frogs]] (''Rana clamitans'') have been found with stomachs full of elm seeds that they had seen floating past.<ref>{{cite journal |author=Hamilton, W. J. Jr. |year=1948 |title=The food and feeding behavior of the green frog, ''Rana clamitans'' Latreille, in New York State |journal=Copeia |volume=1948 |issue=3 |pages=203–207 |publisher=American Society of Ichthyologists and Herpetologists |jstor=1438455 |doi=10.2307/1438455 }}</ref> Toads, salamanders and caecilians also use smell to detect prey. This response is mostly secondary because salamanders have been observed to remain stationary near odoriferous prey but only feed if it moves. Cave-dwelling amphibians normally hunt by smell. Some salamanders seem to have learned to recognize immobile prey when it has no smell, even in complete darkness.{{sfn | Stebbins | Cohen | 1995 | p=56 }}

Amphibians usually swallow food whole but may chew it lightly first to subdue it.<ref name="Collins" /> They typically have small hinged [[pedicellate teeth]], a feature unique to amphibians. The base and crown of these are composed of [[dentine]] separated by an [[Calcification|uncalcified]] layer and they are replaced at intervals. Salamanders, caecilians and some frogs have one or two rows of teeth in both jaws, but some frogs (''Rana spp.'') lack teeth in the lower jaw, and toads (''Bufo spp.'') have no teeth. In many amphibians there are also [[vomerine teeth]] attached to a facial bone in the roof of the mouth.{{sfn | Stebbins | Cohen | 1995 | pp=57–58 }}

[[File:Teichfrosch isst teichfrosch.JPG|thumb|left|alt=Edible frog eating a fellow edible frog|[[Edible frog]] (''Pelophylax esculentus'') exhibiting [[Cannibalism (zoology)|cannibalism]]]]
The [[tiger salamander]] (''Ambystoma tigrinum'') is typical of the frogs and salamanders that hide under cover ready to ambush unwary invertebrates. Other amphibians, such as the ''Bufo spp.'' toads, actively search for prey, while the [[Argentine horned frog]] (''Ceratophrys ornata'') lures inquisitive prey closer by raising its hind feet over its back and vibrating its yellow toes.<ref>{{cite journal |author1=Radcliffe, Charles W. |author2=Chiszar, David |author3=Estep, Karen |author4=Murphy, James B. |author5=Smith, Hobart M. |year=1986 |title=Observations on pedal luring and pedal movements in Leptodactylid frogs |journal=Journal of Herpetology |volume=20 |issue=3 |pages=300–306 |jstor=1564496 |doi=10.2307/1564496 }}</ref> Among leaf litter frogs in Panama, frogs that actively hunt prey have narrow mouths and are slim, often brightly coloured and toxic, while ambushers have wide mouths and are broad and well-camouflaged.<ref>{{cite journal |author=Toft, Catherine A. |year=1981 |title=Feeding ecology of Panamanian litter anurans: patterns in diet and foraging mode |journal=Journal of Herpetology |volume=15 |issue=2 |pages=139–144 |jstor=1563372 |doi=10.2307/1563372 |url=https://www.academia.edu/364846 |access-date=November 10, 2016 |archive-date=July 30, 2020 |archive-url=https://web.archive.org/web/20200730230446/https://www.academia.edu/364846/Feeding_Ecology_of_Panamanian_Litter_Anurans_Patterns_In_Diet_and_Foraging_Mode |url-status=live }}</ref> Caecilians do not flick their tongues, but catch their prey by grabbing it with their slightly backward-pointing teeth. The struggles of the prey and further jaw movements work it inwards and the caecilian usually retreats into its burrow. The subdued prey is gulped down whole.<ref>{{cite journal |author1=Bemis, W. E. |author2=Schwenk, K. |author3=Wake, M. H. |year=1983 |title=Morphology and function of the feeding apparatus in ''Dermophis mexicanus'' (Amphibia: Gymnophiona) |journal=Zoological Journal of the Linnean Society |volume=77 |issue=1 |pages=75–96 |doi=10.1111/j.1096-3642.1983.tb01722.x |url=https://www.academia.edu/23250634 |access-date=November 10, 2016 |archive-date=July 30, 2020 |archive-url=https://web.archive.org/web/20200730223909/https://www.academia.edu/23250634/Morphology_and_function_of_the_feeding_apparatus_in_Dermophis_mexicanus_Amphibia_Gymnophiona_ |url-status=live }}</ref>

When they are newly hatched, frog larvae feed on the yolk of the egg. When this is exhausted some move on to feed on bacteria, algal crusts, detritus and raspings from submerged plants. Water is drawn in through their mouths, which are usually at the bottom of their heads, and passes through branchial food traps between their mouths and their gills where fine particles are trapped in mucus and filtered out. Others have specialised mouthparts consisting of a horny beak edged by several rows of labial teeth. They scrape and bite food of many kinds as well as stirring up the bottom sediment, filtering out larger particles with the papillae around their mouths. Some, such as the spadefoot toads, have strong biting jaws and are carnivorous or even cannibalistic.{{sfn | Stebbins | Cohen | 1995 | pp=181–185 }}
[[file:Sophisticated-Communication-in-the-Brazilian-Torrent-Frog-Hylodes-japi-pone.0145444.s001.oga|left|thumb|Audio showing Brazilian torrent frog males executing advertisement, peep, and squeal calls.]]