编辑“︁魚鰭”︁（章节）

== 產生推力 ==

魚鰭在擺動時可以產生推力，令魚向相反的方向前進。而大多數魚都可以通過擺動鰭來前後移動。在游動中，尾鰭一般是必須用到的鰭，但有些魚主要靠胸鰭來產生推力。<ref name=Sfakiotakis />

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 | caption3  = 黃貂魚通過大的胸鰭獲得推力
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在流動的水中，短時間內因壓力差而導致的氣泡出現與消失會產生[[空穴現象]]。<ref name=Franc>Franc, Jean-Pierre and Michel, Jean-Marie (2004) [http://books.google.co.nz/books?id=QJOQYa_oo24C&printsec=frontcover&dq=Cavitation&hl=en&sa=X&ei=_p6sUNbrHpHimAWjr4CwBg&ved=0CDYQ6AEwAg#v=onepage&q=Cavitation&f=false ''Fundamentals of Cavitation''] Springer. ISBN 0000000000000.</ref>這也是鰭作用的原理之一，[[海豚]]和[[金槍魚]]在遊動時尾鰭可以產生強大的空穴現象。不過雖然可以遊得很快，空穴現象導致的氣泡破滅會使海豚感到疼痛，從而限制其速度的提升。 <ref name=hurts>{{cite news | last = Brahic | first = Catherine | title = Dolphins swim so fast it hurts | publisher = NewScientist | date = 2008-03-28 | url = http://www.newscientist.com/channel/life/dn13553-dolphins-swim-so-fast-it-hurts.html | accessdate = 2008-03-31 | archive-date = 2008-05-18 | archive-url = https://web.archive.org/web/20080518004830/http://www.newscientist.com/channel/life/dn13553-dolphins-swim-so-fast-it-hurts.html | dead-url = no }}</ref>雖然金槍魚因為尾鰭沒有神經，不會感到疼痛，但同樣會因為空穴現象導致的一些其他物理現象而減速。金槍魚尾鰭上發現過空穴現象造成的傷痕。<ref name=hurts/>

[[鯖科]]是技藝高超的游泳者，它們身體後側有小鰭，2000年和2001年的研究指出“在穩定遊動時，小鰭會在局部流體產生流體動力效應”，最後方的小鰭可以增加鯖遊動時尾鰭的推力。<ref>Nauen JC, Lauder GV (2001a) [http://jeb.biologists.org/content/204/13/2251.long "Locomotion in scombrid fishes: visualization of flow around the caudal peduncle and finlets of the Chub mackerel ''Scomber japonicus''"] {{Wayback|url=http://jeb.biologists.org/content/204/13/2251.long |date=20200807052800 }} ''Journal of Experimental Biology'', '''204''': 2251–63.</ref><ref>Nauen JC, Lauder GV (2001b) [http://www.biolbull.org/content/200/1/9.full "Three-dimensional analysis of finlet kinematics in the Chub mackerel ''(Scomber japonicus)''"] {{Wayback|url=http://www.biolbull.org/content/200/1/9.full |date=20150923202302 }} ''The Biological Bulletin'', '''200''': 9–19.</ref><ref>Nauen JC and Lauder GV (2000) [http://jeb.biologists.org/content/203/15/2247.full.pdf "Locomotion in scombrid fishes: morphology and kinematics of the finlets of the Chub mackerel ''Scomber japonicus''"] {{Wayback|url=http://jeb.biologists.org/content/203/15/2247.full.pdf |date=20201001091120 }} ''Journal of Experimental Biology'', '''203''': 2247–59.</ref>