Editing Lung (section)

===Fish===
Lungs are found in three groups of fish; the [[coelacanth]]s, the [[bichir]]s and the [[lungfish]]. Like in tetrapods, but unlike fish with swim bladder, the opening is at the ventral side of the oesophagus. The coelacanth has a nonfunctional and unpaired vestigial lung surrounded by a fatty organ.<ref>{{cite journal | pmc=5717702 | date=2017 | last1=Lambertz | first1=M. | title=The vestigial lung of the coelacanth and its implications for understanding pulmonary diversity among vertebrates: New perspectives and open questions | journal=Royal Society Open Science | volume=4 | issue=11 | doi=10.1098/rsos.171518 | pmid=29291127 | bibcode=2017RSOS....471518L }}</ref> Bichirs, the only group of [[Actinopterygii|ray-finned fish]] with lungs, have a pair which are hollow unchambered sacs, where the gas-exchange occurs on very flat folds that increase their inner surface area. The lungs of [[lungfish]] show more resemblance to tetrapod lungs. There is an elaborate network of parenchymal septa, dividing them into numerous respiration chambers.<ref>{{cite book | url=https://books.google.com/books?id=3bsgS125KH0C&dq=Lungfish+complex+respiratory+surface+septa+honeycomb&pg=PA1864 | title=Encyclopedia of Fish Physiology: From Genome to Environment | date=June 2011 | publisher=Academic Press | isbn=978-0-08-092323-9 }}</ref><ref>{{cite journal | url=https://anatomypubs.onlinelibrary.wiley.com/doi/full/10.1002/ar.20576 | doi=10.1002/ar.20576 | title=Innervation and Neurotransmitter Localization in the Lung of the Nile bichir ''Polypterus bichir bichir'' | date=2007 | last1=Zaccone | first1=Giacomo | last2=Mauceri | first2=Angela | last3=Maisano | first3=Maria | last4=Giannetto | first4=Alessia | last5=Parrino | first5=Vincenzo | last6=Fasulo | first6=Salvatore | journal=The Anatomical Record | volume=290 | issue=9 | pages=1166–1177 | pmid=17722050 }}</ref> In the [[Australian lungfish]], there is only a single lung, albeit divided into two lobes. Other lungfish, however, have traditionally been considered having two lungs, but newer research defines paired lungs as bilateral lung buds that arise simultaneously and are both connected directly to the foregut, which is only seen in tetrapods.<ref>Camila Cupello, Tatsuya Hirasawa, Norifumi Tatsumi, Yoshitaka Yabumoto, Pierre Gueriau, Sumio Isogai, Ryoko Matsumoto, Toshiro Saruwatari, Andrew King, Masato Hoshino, Kentaro Uesugi, Masataka Okabe, Paulo M Brito (2022) [https://elifesciences.org/articles/77156 Lung evolution in vertebrates and the water-to-land transition], ''[[eLife]]''</ref> In all lungfish, including the Australian, the lungs are located in the upper dorsal part of the body, with the connecting duct curving around and above the oesophagus. The blood supply also twists around the oesophagus, suggesting that the lungs originally evolved in the ventral part of the body, as in other vertebrates.<ref name=VB />