Editing Cephalopod (section)

=== Nervous system and behavior ===
{{See also|Cephalopod intelligence|squid giant axon|squid giant synapse|cephalopod aggression}}
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Cephalopods are widely regarded as the most intelligent of the [[invertebrate]]s and have well-developed senses and large [[brain]]s (larger than those of [[gastropod]]s).<ref>{{cite book |last1=Tricarico |first1=E.|last2=Amodio |first2=P. |last3=Ponte |first3=G. |last4=Fiorito |first4=G. |year=2014 |chapter=Cognition and recognition in the cephalopod mollusc ''Octopus vulgaris'': coordinating interaction with environment and conspecifics |editor-last=Witzany |editor-first=G. |title=Biocommunication of Animals |publisher=Springer |pages=337–349 |isbn=978-94-007-7413-1}}</ref> The [[nervous system]] of cephalopods is the most complex of the invertebrates<ref>{{cite book |chapter-url=https://books.google.com/books?id=dW5e6FHOH-4C&pg=PA115 |chapter=The cephalopod nervous system: What evolution has made of the molluscan design |first=B. U. |last=Budelmann|title=The nervous systems of invertebrates: An evolutionary and comparative approach |isbn=978-3-7643-5076-5 |editor1-first=O. |editor1-last=Breidbach |editor2-first=W. |editor2-last=Kutsch |year=1995|publisher=Springer}}</ref><ref>{{Cite journal|last1=Chung |first1=Wen-Sung |last2=Kurniawan |first2=Nyoman D. |last3=Marshall |first3=N. Justin |date=2020 |title=Toward an MRI-Based Mesoscale Connectome of the Squid Brain |journal=iScience|language=en |volume=23|issue=1 |pages=100816 |doi=10.1016/j.isci.2019.100816 |pmc=6974791 |pmid=31972515 |bibcode=2020iSci...23j0816C}}</ref> and their brain-to-body-mass ratio falls between that of [[endotherm]]ic and [[ectotherm]]ic vertebrates.<ref name=Cephalopods/>{{Rp|14}} Captive cephalopods have also been known to climb out of their aquaria, maneuver a distance of the lab floor, enter another aquarium to feed on captive crabs, and return to their own aquarium.<ref>{{Cite book |last=Raven |first=Peter |title=Biology |date=2003 |publisher=McGraw-Hill Education |isbn=9780073383071 |location=New York |pages=669 |display-authors=et al.}}</ref>

The brain is protected in a [[cartilage|cartilaginous]] cranium. The giant [[nerve]] fibers of the cephalopod [[Mantle (mollusc)|mantle]] have been widely used for many years as experimental material in [[neurophysiology]]; their large diameter (due to lack of [[myelination]]) makes them relatively easy to study compared with other animals.<ref>{{cite journal|first1=I. |last1=Tasaki |first2=T. |last2=Takenaka|title=Resting and action potential of squid giant axons intracellularly perfused with sodium-rich solutions |journal=Proceedings of the National Academy of Sciences of the United States of America|volume=50|issue=4|pages=619–626 |date=1963 |doi=10.1073/pnas.50.4.619|pmid=14077488 |pmc=221236 |bibcode=1963PNAS...50..619T |doi-access=free}}</ref>

Many cephalopods are social creatures; when isolated from their own kind, some species have been observed [[Shoaling and schooling|shoaling]] with fish.<ref name=Packard1972>{{cite journal|first1=A. |title=Cephalopods and fish: the limits of convergence|journal=Biological Reviews|volume=47|issue=2 |last1=Packard |pages=241–307 |year=1972 |doi=10.1111/j.1469-185X.1972.tb00975.x |s2cid=85088231}}</ref>

Some cephalopods are able to fly through the air for distances of up to {{convert|50|m}}. While cephalopods are not particularly aerodynamic, they achieve these impressive ranges by jet-propulsion; water continues to be expelled from the funnel while the organism is in the air.<ref name="Macia-Robinson-2004">{{cite journal|last1=Macia |first1=Silvia |last2=Robinson |first2=Michael P. |last3=Craze |first3=Paul |last4=Dalton|first4=Robert|last5=Thomas |first5=James D. |title=New observations on airborne jet propulsion (flight) in squid, with a review of previous reports |doi=10.1093/mollus/70.3.297 |journal=Journal of Molluscan Studies|volume=70|issue=3|pages=297–299 |year=2004 |doi-access=free }}</ref> The animals spread their fins and tentacles to form wings and actively control lift force with body posture.<ref name=MuramatsuEtAl2013>{{cite journal|last1=Muramatsu|first1=K. |last2=Yamamoto |first2=J. |last3=Abe |first3=T. |last4=Sekiguchi |first4=K. |last5=Hoshi |first5=N. |last6=Sakurai |first6=Y. |s2cid=84388744 |year=2013 |title=Oceanic squid do fly |journal=Marine Biology|volume=160|issue=5 |pages=1171–1175 |doi=10.1007/s00227-013-2169-9|bibcode=2013MarBi.160.1171M }}</ref> One species, ''[[Japanese flying squid|Todarodes pacificus]]'', has been observed spreading tentacles in a flat fan shape with a mucus film between the individual tentacles,<ref name=MuramatsuEtAl2013/><ref>{{cite web |url=https://blog.nationalgeographic.org/2013/02/20/scientists-unravel-mystery-of-flying-squid/ |title=Scientists Unravel Mystery of Flying Squid |date=20 February 2013|work=Ocean Views|publisher=National Geographic |access-date=5 August 2019 |archive-date=5 August 2019 |archive-url=https://web.archive.org/web/20190805064024/https://blog.nationalgeographic.org/2013/02/20/scientists-unravel-mystery-of-flying-squid/ |url-status=dead }}</ref> while another, ''[[Caribbean reef squid|Sepioteuthis sepioidea]]'', has been observed putting the tentacles in a circular arrangement.<ref>{{cite journal|last=Jabr |first=Ferris |date=2 August 2010 |title=Fact or Fiction: Can a Squid Fly out of Water? |journal=Scientific American|url=http://www.scientificamerican.com/article/can-squid-fly/}}</ref>