Editing Octopus (section)

{{Short description|Soft-bodied eight-limbed order of molluscs}}
{{About |the order of cephalopod}}
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{{Featured article}}
{{Use dmy dates|date=October 2019}}
{{Use British English|date=May 2017}}
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NOTE: This article uses the English pluralisation, "octopuses". This is correct and intentional, please maintain it. Other variants are discussed in the == Etymology and pluralisation == section.
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{{Automatic taxobox
| fossil_range = {{Fossil range|Middle Jurassic|0|[[Middle Jurassic]] – recent}}
| image = Octopus2.jpg
| image_caption = [[Common octopus]]<br/>(''Octopus vulgaris'')
| image_alt = Common octopus on seabed
| display_parents = 3
| taxon = Octopoda
| authority = [[William Elford Leach|Leach]], 1818<ref>{{cite web |url=https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=82589 |title=ITIS Report: Octopoda Leach, 1818 |publisher=Itis.gov |date=10 April 2013 |access-date=4 February 2014}}</ref>
| subdivision_ranks = Suborders
| subdivision = (traditional)
* [[Cirrina]]
* [[Incirrina]]
See {{section link||Evolution}} for families
| synonyms = * Octopoida<br/><small>Leach, 1817</small><ref name="Mikko">{{cite web |url=http://www.helsinki.fi/~mhaaramo/metazoa/protostoma/mollusca/cephalopoda/coleoidea.html |website=Mikko's Phylogeny Archive |title=Coleoidea&nbsp;– Recent cephalopods}}</ref>
}}

An '''octopus''' ({{Plural form}}: '''octopuses''' or '''octopodes'''{{efn|See {{slink||Etymology and pluralisation}} for variants.}}) is a soft-bodied, eight-limbed [[Mollusca|mollusc]] of the [[order (biology)|order]] Octopoda ({{IPAc-en|ɒ|k|ˈ|t|ɒ|p|ə|d|ə}}, {{respell|ok|TOP|ə|də}}<ref>{{cite Merriam-Webster|Octopoda|access-date=12 July 2021}}</ref>). The order consists of some 300 [[species]] and is grouped within the class [[Cephalopod]]a with [[squid]]s, [[cuttlefish]], and [[nautiloid]]s. Like other cephalopods, an octopus is [[symmetry in biology|bilaterally symmetric]] with two eyes and a [[cephalopod beak|beak]]ed mouth at the centre point of the eight limbs.{{efn|"[[Tentacle]]" is a common [[umbrella term]] for cephalopod limbs. In [[Teuthology|teuthological]] context, octopuses have "arms" with suckers along their entire length while "tentacle" is reserved for appendages with suckers only near the end of the limb, which octopuses lack.<ref>{{cite web|url=https://aquarium.ucsd.edu/blog/get-to-know-the-four-types-of-cephalopods/|title=Get to Know th Four Types of Cephalopod|publisher=U CSan Diego|date=October 11, 2018|last=Scully|first=Caitlin|work=Birch Aquarium Blog|access-date=12 September 2021|archive-date=24 September 2021|archive-url=https://web.archive.org/web/20210924222532/https://aquarium.ucsd.edu/blog/get-to-know-the-four-types-of-cephalopods/|url-status=dead}}</ref>}} An octopus can radically deform its shape, enabling it to squeeze through small gaps. They trail their appendages behind them as they swim. The [[Siphon (mollusc)|siphon]] is used for [[aquatic respiration|respiration]] and [[aquatic locomotion|locomotion]] (by [[jet propulsion#Jet-propelled animals|water jet propulsion]]). Octopuses have a complex nervous system and excellent sight, and are among the most intelligent and behaviourally diverse [[invertebrate]]s.

Octopuses inhabit various [[ocean]] habitats, including [[coral reef]]s, [[pelagic]] waters, and the [[seabed]]; some live in the [[intertidal zone]] and others at [[abyssal zone|abyssal depths]]. Most species grow quickly, mature early, and are short-lived. In most species, the male uses a specially-adapted arm to deliver sperm directly into the female's mantle cavity, after which he becomes [[senescence|senescent]] and dies, while the female deposits fertilised eggs in a den and cares for them until they hatch, after which she also dies. Strategies to defend themselves against predators include expelling [[octopus ink|ink]], [[camouflage]], and [[deimatic display|threat displays]], the ability to jet quickly through the water and hide, and deceit. All octopuses are [[venomous]], but only the [[blue-ringed octopus]]es are known to be deadly to humans.

Octopuses appear in [[mythology]] as sea monsters such as the [[kraken]] of Norway and the [[Akkorokamui]] of the [[Ainu people|Ainu]], and possibly the [[Gorgon]] of [[ancient Greece]]. A battle with an octopus appears in [[Victor Hugo]]'s book ''[[Toilers of the Sea]]''. Octopuses appear in Japanese ''[[shunga]]'' erotic art. They are eaten and considered a delicacy by humans in many parts of the world, especially the [[Mediterranean cuisine|Mediterranean]] and Asia.