Cephalopod intelligence explained

Cephalopod intelligence is a measure of the cognitive ability of the cephalopod class of molluscs.

Intelligence is generally defined as the process of acquiring, storing, retrieving, combining, comparing, and recontextualizing information and conceptual skills.[1] Though these criteria are difficult to measure in nonhuman animals, cephalopods are the most intelligent invertebrates. The study of cephalopod intelligence also has an important comparative aspect in the broader understanding of animal cognition because it relies on a nervous system fundamentally different from that of vertebrates.[2] In particular, the Coleoidea subclass (cuttlefish, squid, and octopuses) is thought to be the most intelligent invertebrates and an important example of advanced cognitive evolution in animals, though nautilus intelligence is also a subject of growing interest among zoologists.[3]

The scope of cephalopod intelligence and learning capability is controversial within the biological community, complicated by the inherent complexity of quantifying non-vertebrate intelligence. In spite of this, the existence of impressive spatial learning capacity, navigational abilities, and predatory techniques in cephalopods is widely acknowledged.[4] [5] Cephalopods have been compared to hypothetical intelligent extraterrestrials, due to their independently evolved mammal-like intelligence.[6]

Brain size and structure

Cephalopods have large, well-developed brains,[7] [8] [9] and their brain-to-body mass ratio is the largest among the invertebrates, falling between that of endothermic and ectothermic vertebrates.[10]

The nervous system of cephalopods is the most complex of all invertebrates.[11] The giant nerve fibers of the cephalopod 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.[12]

Behavior

Predation

Unlike most other molluscs, all cephalopods are active predators (with the possible exceptions of the bigfin squid and vampire squid). Their need to locate and capture their prey has likely been the driving evolutionary force behind the development of their intelligence.[13]

Crabs, the staple food source of most octopus species, present significant challenges with their powerful pincers and their potential to exhaust the cephalopod's respiration system from a prolonged pursuit. In the face of these challenges, octopuses will instead seek out lobster traps and steal the bait inside. They are also known to climb aboard fishing boats and hide in the containers that hold dead or dying crabs.[14] [15]

Captive cephalopods have also been known to climb out of their tanks, maneuver a distance of the lab floor, enter another aquarium to feed on the crabs, and return to their own aquariums.[16] [17] [18]

Communication

Although believed to not be the most social of animals, many cephalopods are in fact highly social creatures; when isolated from their own kind, some species have been observed shoaling with fish.[19]

Cephalopods are able to communicate visually using a diverse range of signals. To produce these signals, cephalopods can vary four types of communication elements: chromatic (skin coloration), skin texture (e.g. rough or smooth), posture, and locomotion. Changes in body appearance such as these are sometimes called polyphenism.[20] Some cephalopods are capable of rapid changes in skin colour and pattern through nervous control of chromatophores.[21] This ability almost certainly evolved primarily for camouflage, but squid use color, patterns, and flashing to communicate with each other in various courtship rituals.[20] Caribbean reef squid can even discriminate between recipients, sending one message using color patterns to a squid on their right, while they send another message to a squid on their left.[22] [23] Octopuses have been found to become more sociable when exposed to the psychoactive drug MDMA.[24]

The Humboldt squid shows extraordinary cooperation and communication in its hunting techniques. This is the first observation of cooperative hunting in invertebrates.[25]

It is believed that squids are slightly less intelligent than octopuses and cuttlefish; however, various species of squid are much more social and display greater social communications, etc., leading to some researchers concluding that squids are on par with dogs in terms of intelligence.[26]

Learning

In laboratory experiments, octopuses can be readily trained to distinguish between different shapes and patterns, and one study concluded that octopuses are capable of using observational learning;[27] [28] however, this is disputed.[29] [30]

Octopuses have also been observed in what has been described as play: repeatedly releasing bottles or toys into a circular current in their aquariums and then catching them.[31]

Cephalopods can demonstrably benefit from environmental enrichment[32] indicating behavioral and neuronal plasticity not exhibited by many other invertebrates.

In a study on social learning, common octopuses (observers) were allowed to watch other octopuses (demonstrators) select one of two objects that differed only in color. Subsequently, the observers consistently selected the same object as did the demonstrators.[33]

Both octopuses and nautiluses are capable of vertebrate-like spatial learning.[34]

Tool use

The octopus has repeatedly been shown to exhibit flexibility in the use of tools.

At least four individuals of the veined octopus (Amphioctopus marginatus) have been observed retrieving discarded coconut shells, manipulating them, transporting them some distance, and then reassembling them for use as shelter.[35] It is surmised that the octopuses used bivalves for the same purpose before humans made coconut shells widely available on the sea floor.[36] [37] Other sea creatures construct homes in a similar manner; most hermit crabs use the discarded shells of other species for habitation, and some crabs place sea anemones on their carapaces to serve as camouflage. However, this behavior lacks the complexity of the octopus's fortress behavior, which involves picking up and carrying a tool for later use. (This argument remains contested by a number of biologists, who claim that the shells actually provide protection from bottom-dwelling predators in transport.[38]) Octopuses have also been known to deliberately place stones, shells, and even bits of broken bottles to form walls that constrict their den openings.[39]

In laboratory studies, Octopus mercatoris, a small pygmy species of octopus, has been observed to block its lair using plastic Lego bricks.[40]

Smaller individuals of the common blanket octopus (Tremoctopus violaceus) hold the tentacles of the Portuguese man o' war (whose venom they are immune to), both as means of protection and as a method of capturing prey.[41]

Problem-solving ability

The highly sensitive suction cups and prehensile arms of octopuses, squid, and cuttlefish allow them to hold and manipulate objects. However, unlike vertebrates, the motor skills of octopuses do not seem to depend upon mapping their body within their brains, as the ability to organize complex movements is not thought to be linked to particular arms.[42]

Cephalopods can solve complex puzzles requiring pushing or pulling actions, and can also unscrew the lids of containers and open the latches on acrylic boxes in order to obtain the food inside. They can also remember solutions to puzzles and learn to solve the same puzzle presented in different configurations.[43]

Captive octopuses require stimulation or they will become lethargic; this typically takes the form of a variety of toys and puzzles.[44] At an aquarium in Coburg, Germany, an octopus named Otto was known to juggle his fellow tank-mates around, as well as throw rocks to smash the aquarium glass. On more than one occasion, Otto even caused short circuits by crawling out of his tank and shooting a jet of water at the overhead lamp.[45]

Additionally, cephalopods have been shown to have the capacity for future planning and reward processing after being tested with the Stanford marshmallow experiment.[46]

Protective legislation

Due to their intelligence, cephalopods are commonly protected by animal testing regulations that do not usually apply to invertebrates.

In the UK from 1993 to 2012, the common octopus (Octopus vulgaris) was the only invertebrate protected under the Animals (Scientific Procedures) Act 1986.[47] Since 2022, all vertebrates, cephalopods, and decapods have been recognised as sentient by the Animal Welfare (Sentience) Act 2022.

Cephalopods are the only invertebrates protected under the 2010 European Union directive "on the protection of animals used for scientific purposes".[48]

In 2019, some scholars have argued for increased protections for cephalopods in the United States as well.[49]

See also

Further reading

Notes and References

  1. Humphreys. Lloyd G.. Lloyd Humphreys. April–June 1979. The construct of general intelligence. live. Intelligence. editorial. 3. 2. 105–120. 10.1016/0160-2896(79)90009-6. 0160-2896. https://web.archive.org/web/20170812230808/https://www.beteronderwijsnederland.nl/files/construct%20of%20G%20Humphreys%201979.pdf. 12 August 2017. 13 December 2020.
  2. http://www.daviddarling.info/encyclopedia/C/cephalopodintel.html "Cephalopod intelligence"
  3. Crook. Robyn. Basil. Jennifer. 2008. A biphasic memory curve in the chambered nautilus, Nautilus pompilius L. (Cephalopoda: Nautiloidea). live. Journal of Experimental Biology. 211. 12. 1992–1998. 10.1242/jeb.018531. 18515730. https://web.archive.org/web/20181104170130/https://jeb.biologists.org/content/jexbio/211/12/1992.full.pdf. 4 November 2018. 13 December 2020. free. amp.
  4. News: Hunt. Elle. 28 March 2017. Alien intelligence: the extraordinary minds of octopuses and other cephalopods. The Guardian. live. https://web.archive.org/web/20200418101916/https://www.theguardian.com/environment/2017/mar/28/alien-intelligence-the-extraordinary-minds-of-octopuses-and-other-cephalopods. 18 April 2020.
  5. News: Bilefsky. Dan. April 13, 2016. Inky the Octopus Escapes From a New Zealand Aquarium. The New York Times. live. limited. 24 April 2016. https://web.archive.org/web/20200416193614/https://www.nytimes.com/2016/04/14/world/asia/inky-octopus-new-zealand-aquarium.html. 16 April 2020.
  6. Web site: Baer . Drake . 20 December 2016 . Octopuses Are 'the Closest We Will Come to Meeting an Intelligent Alien' . Science of Us . 26 April 2017 .
  7. Book: Tricarico. Elena. Biocommunication of Animals. Amodio. Piero. Ponte. Giovanna. Fiorito. Graziano. Springer. 2014. 978-94-007-7413-1. Witzany. Guenther. 337–349. Cognition and recognition in the cephalopod mollusc Octopus vulgaris: coordinating interaction with environment and conspecifics. 10.1007/978-94-007-7414-8_19. 2019748877.
  8. Chung. Wen-Sung. Kurniawan. Nyoman D.. Marshall. N. Justin. 2020. Toward an MRI-Based Mesoscale Connectome of the Squid Brain. iScience. 23. 1. 100816. 10.1016/j.isci.2019.100816. 2589-0042. 6974791. 31972515. 2020iSci...23j0816C. free.
  9. Chung. Wen-Sung. Kurniawan. Nyoman D.. Marshall. N. Justin. 2021-11-18. Comparative brain structure and visual processing in octopus from different habitats. Current Biology. 32. 1 . 97–110.e4. English. 10.1016/j.cub.2021.10.070. 0960-9822. 34798049. 244398601. free.
  10. Book: The Brains and Lives of Cephalopods. Nixon. Marion. Young. John Z.. 4 September 2003. Oxford University Press. 978-0198527619. 2002041659. November 6, 2003. John Zachary Young.
  11. Book: Budelmann, B. U.. The nervous systems of invertebrates: An evolutionary and comparative approach. Birkhäuser. 1995. 978-3-7643-5076-5. Breidbach. O.. The cephalopod nervous system: What evolution has made of the molluscan design. 94035125. Kutsch. W.. https://books.google.com/books?id=dW5e6FHOH-4C&pg=PA115.
  12. Tasaki. I.. Takenaka. T.. October 1963. Resting and action potential of squid giant axons intracellularly perfused with sodium-rich solutions. live. Proceedings of the National Academy of Sciences of the United States of America. 50. 4. 619–626. 1963PNAS...50..619T. 10.1073/pnas.50.4.619. 221236. 14077488. https://web.archive.org/web/20180811010907/https://www.pnas.org/content/pnas/50/4/619.full.pdf. 11 August 2018. 13 December 2020. free.
  13. Villanueva. Roger. Perricone. Valentina. Fiorito. Graziano. 2017-08-17. Cephalopods as Predators: A Short Journey among Behavioral Flexibilities, Adaptions, and Feeding Habits. Frontiers in Physiology. 8. 598. 10.3389/fphys.2017.00598. 1664-042X. 5563153. 28861006. free.
  14. [Jacques-Yves Cousteau|Cousteau, Jacques Yves]
  15. Web site: Giant Octopus – Mighty but Secretive Denizen of the Deep. 2 January 2008. Smithsonian National Zoological Park. https://web.archive.org/web/20120825030432/http://nationalzoo.si.edu/Support/AdoptSpecies/AnimalInfo/GiantOctopus/default.cfm. 25 August 2012. dead. 4 February 2014.
  16. Wood. J. B. Anderson. R. C. 2004. Interspecific Evaluation of Octopus Escape Behavior. Journal of Applied Animal Welfare Science. 7. 95–106. 10.1207/s15327604jaws0702_2. 15234886. 11 September 2015. 2. 16639444.
  17. Book: Lee, Henry. . Aquarium Notes – The Octopus; or, the "devil-fish" of fiction and of fact. 1875. Chapman and Hall. London. 38–39. V: The octopus out of water. 1544491. The marauding rascal had occasionally issued from the water in his tank, and clambered up the rocks, and over the wall into the next one; there he had helped himself to a young lump-fish, and, having devoured it, returned demurely to his own quarters by the same route, with well-filled stomach and contented mind.. 11 September 2015.
  18. News: The great escape: Inky the octopus legs it to freedom from aquarium. Roy. Eleanor Ainge. 14 April 2016. The Guardian (Australia).
  19. Packard . A. . 1972 . Cephalopods and fish: The limits of convergence . Biological Reviews . 47 . 2 . 241–307 . 10.1111/j.1469-185X.1972.tb00975.x. 85088231 .
  20. Brown . C. . Garwood . M. P.. Williamson . J.E. . 2012 . It pays to cheat: Tactical deception in a cephalopod social signalling system . Biology Letters . 8 . 5 . 729–732 . 10.1098/rsbl.2012.0435 . 3440998 . 22764112.
  21. Cloney . R.A. . Florey . E. . 1968 . Ultrastructure of cephalopod chromatophore organs . Z. Zellforsch. Mikrosk. Anat. . 89 . 2 . 250–280 . 10.1007/BF00347297 . 5700268. 26566732 .
  22. Web site: Sepioteuthis sepioidea, Caribbean Reef squid . The Cephalopod Page . 2010-01-20 . dmy-all.
  23. Byrne, R.A. . Griebel, U. . Wood, J.B. . Mather, J.A. . 2003 . Squids say it with skin: A graphic model for skin displays in Caribbean Reef Squid . Berliner Geowissenschaftliche Abhandlungen . 3 . 29–35.
  24. News: Nuwer . Rachel . Rachel Nuwer . Rolling under the Sea: Scientists Gave Octopuses Ecstasy to Study Social Behavior . Scientific American . en.
  25. Behold the Humboldt squid . Tim . Zimmermann . Outside Magazine . July 2006 .
  26. Web site: 2020-02-10. Are squids as smart as dogs?. 2021-06-07. www.medicalnewstoday.com. en.
  27. Fiorito. Graziano. Scotto. Pietro. 24 April 1992. Observational Learning in Octopus vulgaris. Science. 256. 5056. 545–547. 10.1126/science.256.5056.545. 17787951. 18 February 2015. 1992Sci...256..545F. 29444311.
  28. News: Octopus intelligence: Jar opening. 25 February 2003. 4 February 2014. BBC News.
  29. News: What is this octopus thinking?. Hamilton. Garry. 7 June 1997. New Scientist. 18 February 2015. 2085. 30–35.
  30. Stewart. Doug. 1997. Armed but not dangerous: Is the octopus really the invertebrate intellect of the sea. National Wildlife. 35. 2.
  31. Web site: What behavior can we expect of octopuses?. Mather. J. A.. Anderson. R. C.. 1998. Wood. J. B.. The Cephalopod Page.
  32. Book: Octopus: The Ocean's Intelligent Invertebrate. Mather, J.A., Anderson, R.C. and Wood, J.B.. Timber Press. 2010.
  33. Fiorito, G.. Scotto, P.. amp. 1992. Observational learning in Octopus vulgaris. Science. 256. 5056. 545–547. 10.1126/science.256.5056.545. 17787951. 1992Sci...256..545F. 29444311.
  34. Crook, R.J.. Walters, E.T.. amp. 2011. Nociceptive behavior and physiology of molluscs: animal welfare implications. ILAR Journal. 52. 2. 185–195. 10.1093/ilar.52.2.185. 21709311. free.
  35. Finn. Julian K.. Tregenza. Tom. Norman. Mark D.. 15 December 2009. Defensive tool use in a coconut-carrying octopus. live. Current Biology. 19. 23. R1069–R1070. 10.1016/j.cub.2009.10.052. 20064403. https://web.archive.org/web/20170811002225/https://sites.oxy.edu/clint/learn/articles/defensivetooluseinacoconutcarryingoctopus.pdf. 11 August 2017. Occidental College. free.
  36. News: Morelle. Rebecca. Rebecca Morelle. 14 December 2009. Octopus snatches coconut and runs. BBC News. live. 20 January 2010. https://web.archive.org/web/20200531101841/http://news.bbc.co.uk/2/hi/science/nature/8408233.stm. 31 May 2020.
  37. Web site: Coconut shelter: evidence of tool use by octopuses | EduTube Educational Videos. 2009-12-14. Edutube.org. https://web.archive.org/web/20131024173037/http://edutube.org/video/coconut-shelter-evidence-tool-use-octopuses. 2013-10-24. dead. 2010-01-20.
  38. published January 26, 2010 New Scientist
  39. Web site: Simple tool use in owls and cephalopods. 2010. Map Of Life. July 23, 2013.
  40. Oinuma, Colleen, (14 April 2008). "Octopus mercatoris response behavior to novel objects in a laboratory setting: Evidence of play and tool use behavior?" In Octopus Tool Use and Play Behaviorhttp://nature.berkeley.edu/classes/es196/projects/2008final/Oinuma_2008.pdf
  41. Jones. Everet C.. 22 February 1963. Tremoctopus violaceus uses Physalia tentacles as weapons. Science. 139. 3556. 764–766. 1963Sci...139..764J. 10.1126/science.139.3556.764. 1710225. 17829125. 40186769.
  42. Zullo. Letizia. Sumbre. German. Agnisola. Claudio. Flash. Tamar. Tamar Flash. Hochner. Binyamin. 17 September 2009. Nonsomatotopic organization of the higher motor centers in octopus. live. Current Biology. 19. 19. 1632–6. 10.1016/j.cub.2009.07.067. 19765993. https://web.archive.org/web/20200709055946/http://www.octopus.huji.ac.il/site/articles/Zullo-2009.pdf. 9 July 2020. 13 December 2020. free.
  43. Richter. Jonas N.. Hochner. Binyamin. Kuba. Michael J.. 2016-03-22. Pull or Push? Octopuses Solve a Puzzle Problem. PLOS ONE. en. 11. 3. e0152048. 10.1371/journal.pone.0152048. 27003439. 4803207. 1932-6203. 2016PLoSO..1152048R. free.
  44. Web site: Captive Octopuses Need Intellectual Stimulation Or Else They Get Bored. curiosity.com. 2018-11-19.
  45. News: 31 October 2008. Otto the octopus wreaks havoc. The Telegraph. live. subscription. https://web.archive.org/web/20110624091024/https://www.telegraph.co.uk/news/newstopics/howaboutthat/3328480/Otto-the-octopus-wrecks-havoc.html. 24 June 2011.
  46. Web site: Starr. Michelle. A Cephalopod Has Passed a Cognitive Test Designed For Human Children. 2021-03-03. ScienceAlert. 3 March 2021 . en-gb.
  47. Web site: The Animals (Scientific Procedures) Act (Amendment) Order 1993. The National Archives. 18 February 2015.
  48. Web site: DIRECTIVE 2010/63/EU OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL. Official Journal of the European Union. Article 1, 3(b). 18 February 2015.
  49. Zabel. Joseph. Spring 2019. Legislators Need to Develop a Backbone for Animals that Lack One: Including Cephalopods in the Animal Welfare Act. Journal of Animal and Environmental Law. University of Louisville School of Law. 10. 2. 1.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Cephalopod intelligence".

Except where otherwise indicated, Everything.Explained.Today is © Copyright 2009-2024, A B Cryer, All Rights Reserved. Cookie policy.