Talk:Octopus/Archive 1

This is an archive of past discussions about Octopus. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page.

Archive 1

Archive 2

Marine biologist?

Is there a marine biologist in the house? This brief article makes no mention of the many interesting traits unique to octopuses, such as: ink sacs, color changing (though the article on cephalapods does mention it,) lack of any bones, three-heart circulatory system, and hunting habits. Could someone please update, I trust not my amateur knowledge. One source - Nocturnal (not a registered user)

Very short life span?

The article says that they 'have a very short life span.' Just how long is it? Kent Wang 05:21, 28 Apr 2004 (UTC)

Arms, Tentacles or Limbs

The article says: Octopuses are characterized by their eight legs (properly called "tentacles").... Is this correct?

I had the impression that the eight legs were properly called 'arms' and that 'tentacles' referred to something else, the two additional long paddle-ended appendages of the giant squid for example. Thus one might say that the squid has eight arms and two tentacles. See, for example, http://www.australiancephalopods.com/occy_features.html: "One of the best known features of Octopuses is the fact that they have eight arms" This page uses the word 'arms' four times and 'tentacles' not at all; it was written by Dr. Mark Norman, a world-famous expert on cephalopods. Similarly, http://marine.alaskapacific.edu/octopus/anatomy.html uses the word 'arm', not 'tentacle'.

If there's no objection, I will correct the terminology in the article. Dominus 06:37 Apr 20, 2003 (UTC)

In Italy we're used to referring to the two long tentacles of squids as arms ("braccia"). The normal tentacles of octopuses and squids are always tentacoli, nor "legs" or "arms". Carnby.

Which one should be used. I'm not so sure that "arms" should be the term used, as they are technically neither arms nor legs. Why was tentacles removed?

The argument at the top of this page doesn't seem to have reached any real conclusion. Just that Marine biologists (and many other scientists) are inconsistent and international--ZayZayEM 22:20, 14 Oct 2004 (UTC)

Typical english is to use "arm" for the four pairs of appendages common through all the coleoidea, and "tentacles" for the extra pair. - UtherSRG 12:43, 15 Oct 2004 (UTC)

Should not "limbs" then be used when describing all 8?--ZayZayEM 07:46, 16 Oct 2004 (UTC)

No. See the article on squid: "Squid ... have eight arms and two tentacles arranged in pairs". Octopuses have the eight arms, but not the two tentacles. -- Dominus 04:46, 17 Oct 2004 (UTC)

I tend to think that the arms of octopuses are tentacles that are called arms in a same way as starfishes are called fishes, but they still are echinoderms, not actual fishes. This http://jrscience.wcp.muohio.edu/fieldcourses03/PapersMarineEcologyArticles/THEJETSET.THEANATOMYOFSWIA.html article says "The tentacles of cephalopods are perhaps their most notable feature. The number and characteristics of different types of tentacles are key to identifying different species. The Octopus (Octopoda) has eight tentacles (often called legs or arms)." I also searched for other pages, and they also speak of the arms as tentacles:

http://userwww.sfsu.edu/~biol240/labs/lab_18molluscs/pages/cephalopods.html

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20102/Bio%20102%20lectures/Sensory%20Systems/sensory.htm

and this news that uses "arms" and "tentacles" interchangebly:

http://iubio.bio.indiana.edu:7131/bionet/mm/deepsea/2003-February/000572.html

I think that scientist don't refer to tentacles that often for the same reason that starfishes aren't referred as "star echinoderms", and often people refer the arms of octopuses as tentacles, so I think the article should say something like "octopuses have eight tentacles, which are usualley called arms".89.166.21.54 (talk) 17:02, 11 December 2007 (UTC)

I disagree with ZayZayEM's evaluation. English scientific usage is as UtherSRG said, and consistently so. The terms used by Italian biologists when speaking in Italian are irrelevant since the article is written in English. -- Dominus 14:16, 15 Oct 2004 (UTC)

Cephalopods have up to ten appendages extending from around the mouth. Squids, cuttlefish and octopods (octopuses, plus deep water forms) have eight arms that have suckers and/or hooks along the entire length (octopuses only have suckers, squids can have suckers and/or hooks, depending on the species). Squids and cuttlefish also have two tentacles- long stretchy appendages that can shoot out to catch prey and bring food to the mouth. Tentacles only have suckers and/or hooks at the end (called the club). Octopods lack tentacles, and only have eight arms. The deep water octopod Vampyroteuthis also has two "filaments" which have no suckers or hooks. The function of filaments is unknown, but they are anatomically different from arms and tentacles.

The unsigned person above is correct. One must compare with squids and cuttlefish: eight arms and two long tentacles. Octopuses have eight arms and no tentacles. Many links will say tentacles because of the unfortunate misconceptions that have become too common. Reywas92^Talk 22:07, 11 December 2007 (UTC)

plural

As the article correctly says, octopi is not the correct English plural. It is not, however, a 'misconception' that octopus is from Latin. The OED states that octopus derives from modern Latin octōpus, which in turn derives from Greek. -- Heron

And how does the "common misconception" that octopus is Latin give us a plural which is so close to the original Greek oktopoi and so different from the Latin octopedes. If anything it sounds like octopi is anglicized Greek

The common misconception stems from the -pus ending. It is a Latin ending, but not when it means "foot". The Latin -pus means something else. The Greek plural of -pus is -poi, while the Latin plural is -pi. cf. cactus - UtherSRG 16:49, 5 Oct 2004 (UTC)

No, it is not. The Greek plural form of (okto)pous is (okto)podes. The term pous, podos, plural: podes ('foot' but also 'leg') is an "irregular noun" (much better: a diphthong stem). I've studied Greek at the university and checked also Liddell-Scott dictionary. It must be said also that oktapous/oktapodes (with accented alpha) was even more common than oktopous (with accented omega) in ancient Greece... Carnby

Either form, octopuses or octopi is acceptable. Check a dictionary. Exploding Boy 21:07, Nov 15, 2004 (UTC)

Octopi has become an acceptable alternatve through decades of misuse, but as English is a living language this has to be taken on the chin I guess.

Octopus is latin, as all scientific names. Octopus is latinized greek and latin rules are applied. --Luis Fernández García 21:34, 10 October 2005 (UTC)

If octopus is Latinized Greek, then how is octopus (spelled the same but pronounced differently) not Anglicized Latin, and must therefore require English rules? -- Cevlakohn

Can someone please add the omikron to the Greek singular and plural forms? Exploding Boy 16:50, Nov 22, 2004 (UTC)

Which one? Another "small letter omicron with psili" (ὀ), or a simple "small letter omicron" (ο)? I admit it's all Greek to me, but could you explain why there would be only 11 Google hits for οχταπόδι but 3830 for χταπόδι? - And after all that work you removed the 'term of endearment'? Femto 19:51, 22 Nov 2004 (UTC)

χταπόδι is a colloquialism. Just as we don't write "gunna" in formal writing, we shouldn't be writing "khtapothi"; the word is okhtapothi, from "okhta", meaning 8, and "pothia," meaning legs. Exploding Boy 20:05, Nov 22, 2004 (UTC)

Do the Greeks know this? Femto 20:33, 22 Nov 2004 (UTC)

If you'd like to rephrase your question so it's both understandable and non-sarcastic, I'll try to reply. Exploding Boy 20:53, Nov 22, 2004 (UTC)

A quick check at two online dictionaries, this and babelfish, returned only the chi variant. I'd like to know from what authority do you speak, and is it applicable to an encyclopedia that should describe the common usage and not necessarily always the correct one. Femto 21:38, 22 Nov 2004 (UTC)

I grew up speaking and reading Greek, though admittedly I've largely lost it now. I looked at some of the online sources available; none seems particularly reliable, though I did find what appeared to be a scholarly article that Octopi also have eight penises contained both versions. I'll try looking in a proper dictionary, but at least both variants should be mentioned. Exploding Boy 21:59, Nov 22, 2004 (UTC)

Good enough for me. I would agree that the formal variant should also be given, if the modern Greek word wasn't just an aside to the derivation of the English plural for the animal. It's obvious that somewhere on the way from ancient Greek an ο went missing, and if the 11:3830 ratio reflects common use, I'd say 'skip it' and just give the chi variant. Interestingly, many of those 11 hits are from restaurant menus. (And a Greek-Finnish word list, of all things. What is it with those Scandinavians? :) If it would be enough to mention the existance of the formal variant, how's the current edit? Femto 11:58, 23 Nov 2004 (UTC)

The term 'Octopi" is incorrect. The root of "octopus" is Greek, and technically the plural is Octopodes. Since there is a group of animals called Octopods, the use of the Greek plural could be confusing (although some people do use it). Thus, cephalopod biologists use the English pluralization "octopuses" and absolutely cringe at the term "octopi."

Since this plural issue seems to come up a lot and cause many headaches, I have copied here the bit from the OED on line. (You can only access if it you have an account--if you're at at University you probably do.) I can't seem to get the Greek characters to show up, so I've cut them out.

Quote from OED
Plural octopuses, octopi, (rare) octopodes ... scientific Latin octopus (1758 or earlier in Linnaeus) ancient Greek (cut out Greek characters here) eight-footed, an eight-footed creature

The plural form octopodes reflects the Greek plural; cf. OCTOPOD n. The more frequent plural form octopi arises from apprehension of the final -us of the word as the grammatical ending of Latin second declension nouns; this apprehension is also reflected in compounds in octop-: see e.g. OCTOPEAN a., OCTOPIC a., OCTOPINE a., etc.
End OED Quote

I hope this will resolve some of the factual issues about how the different variants came about, if not ultimately the philosophical struggle between prescriptivist and descriptivist grammarains. 204.130.0.8 17:15, 14 September 2006 (UTC)

Octopi, Octipodes and Octopuses are all legitimate uses - they are all used in common parlance. Thos that dispute one or the other may be correct in a narrow/pedantic way - and the issue really is if a dictionary defines acceptable use, or follows common use - Hence the use of Fowlers in the article is rather biased since it is passing as a judgement, the author's opinion on which plural form is correct when all are used commonly and grammatically correctly. Because this is a STYLE GUIDE and not a dictionary, it describes a preferred useage rather than correct useage. Would it be OK to do that? --Bromo@ix.netcom.com —The preceding unsigned comment was added by 65.116.131.6 (talk • contribs) 20:02, December 7, 2006 (UTC).

Per Wikipedia's policy of verifiability, we can't just take your word that "octipodes" (sic) is in common parlance. According to the OED quote above, "octopodes" is rare. Citing what Fowlers says, with proper attribution, does not bias the article. All of the article's discussion of the various plural forms is properly attributed to dictionaries and style guides. I can, however, accept re-arranging the order of the section to first cite the dictionaries and then cite the style guides. schi ^talk 20:21, 7 December 2006 (UTC)

I can go in and rearrange if you agree - I think that this is a good thing. I agree that the plural octopuses is the best one, but the others are used, too, and to correct, they have to be mentioned. :) —The preceding unsigned comment was added by Bromo33333 (talk • contribs).

I like the terminology entry a lot. Seems to me to cover all the bases. Thanks to the editing author! Bromo33333

"Octopi" should be marked as a commonly used, but INCORRECT, plural. At the very least the dispute should be mentioned in the article. —Preceding unsigned comment added by 76.173.49.8 (talk) 15:29, 17 April 2008 (UTC)

As Bromo33333 said just above, there is a well-written section on "Terminology" which covers the issue. While I agree that "octopi" is incorrect, I think this section achieves the appropriate encyclopedic balance: descriptive rather than prescriptive, while leaving no-one in any doubt that "octopi" is based on a misunderstanding. Vilĉjo (talk) 19:39, 29 May 2008 (UTC)

Greek or Latin??

According to the numerical prefix articles, it says that octa- is Greek and octo- is Latin. However, this article says that octo- is Greek. Any opinions?? 66.245.107.78 01:46, 15 Oct 2004 (UTC)

All those octa/okto variants share the same Indo-European roots, if I got that right. Since then, those languages kept developing their own forms, as well as borrowing freely from each other. There may be a pattern, but it should be difficult to determine which is which only from the prefix of a word. This is the point, the article makes no hint at the origin of the prefix itself, just at that of the compound word. (I have no idea what this means for the other articles.) Femto 20:55, 5 Nov 2004 (UTC)

By the way, "nautilus" is another Latinized Greek word. Fortunately the link works just as well in the singular here. See Talk:Nautilus. Femto 20:55, 5 Nov 2004 (UTC)

Octopus is a word in Scientific Latin, an adaptation of the cognate Ancient Greek word. In the etymology section, it is WRONG to write Greek right away: English has not borrowed this word from Greek, but from Latin. That the Scientific Latin word is a Greek loan word changes nothing to this fact. By the way, octa- also exists in Greek. Yet octo>octa is a common vowel mutation for Latin words borrowed from Greek. I had corrected it, some very insightful person changed it back. I leave it to her/him to put down the right version. --Ekindedeoglu (talk) 19:03, 13 April 2008 (UTC)

image

This photo is good, but I'd like see one which more prominently displays its eight tentacles. Kent Wang 05:19, 28 Apr 2004 (UTC)

I'd like to see either an image or video of chromatophores in action directly in the octopus article, and not only in the chromatophore article. joelloughead

Does anyone know the species depicted in the image? - UtherSRG 12:31, 26 Oct 2004 (UTC)

Not a clue, but according to http://www.photolib.noaa.gov/reef/reef2063.htm it was taken by Mohammed Al Momany in the Gulf of Aqaba, Red Sea. Femto 15:11, 26 Oct 2004 (UTC)

It's Octopus cyanea. You can tell by the red background, white arm spots, and the barely-visible ocellus (false eyespot) on the side.

as seafood

>> In some cultures, octopuses are caught for food.

Removed it because there's virtually no edible animal that isn't eaten somewhere. Which cultures? Octopus is a worldwide exported seafood, you can probably find some at your local supermarket. Still it would be worth to mention the seafood aspect somehow. How many million tons? Yes, millions - according to [1] about 2.5 million tons of cephalopods are harvested each year (I found no data about octopus in particular). Those pesky dolphins shouldn't get all the attention, eh? Femto 14:51, 29 Oct 2004 (UTC)

I think that fact is worth mentioning, in my country, Portugal, everybody eats octopus, and octopus fishing is an important activity in several coastal villages. Mário 21:14, 5 April 2006 (UTC)

self?

the article says: "Octopuses also understand the concept of mirrored images and soon realize there's no use attempting to attack their own images. This seems to suggest that octopuses have some concept of a self; otherwise only monkeys, apes and humans, and possibly some species of dolphins, are smart enough to understand that their mirrored images are not other animals."

As stated, this does not seem tenable. Chimpanzees are thought to have a concept of self because they groom themselves in the mirror, showing that they can conceptually grasp that it is them being reflected back on themselves [needs reference]. Just not attacking the mirror does not demonstrate an awareness of self. Dogs and cats can do this. It seems that this evidence is pretty neutral with regard to whether the Octopus has a "concept of self". - anon

You may be correct. An octopus's sense of taste (via their suckers) is high acute. They may get the point that attacking a mirror is pointless because they get no octopus taste (besides its own) from the mirror. However, it shouldn't be removed, only expanded to give other possibilities. - UtherSRG 21:03, 15 Nov 2004 (UTC)

Octopussy

>> Finally, there's octopussy (plural octopussies), which is used in British English and is based on a popular derivation from "pussy" ('she-cat'), but it's completely erroneous.

To clarify, Octopussy is a James Bond movie, which is named after the Book by Ian Fleming, which in turn is named after one of the characters, who in turn is named by a blend of "octopus" and "pussycat" (obvious, but speculating here, I don't know the book or if there were earlier uses). Octopussy could be called a portmanteau word, but 'blend' seems more common and is just fine. Giving the trivial octopussies-plural here made little sense to me. Also it's less distracting to simply say "pussycat".

The Octopussy of the book ("Octopussy" is the eponymous short story) is an actual octopus who is being fed regularly like a pet by the story's protagonist who is actually Bond's target. Bond shows up and pops the guy, and accidentally/onpurpose his body gets eaten by the octopus (not necessarily the whole thing, it's unclear). The depiction is more realistic than the crazy squid of "Dr. No" but still a bit fanciful. Just thought I'd fill in that blank here.24.33.28.52 18:38, 25 May 2006 (UTC)

Re:British English - It's not in my dictionary, so to speak. The web search for "site:uk octopussy -bond" was ...interesting, but can you cite some real uses? Femto 18:36, 18 Nov 2004 (UTC)

Nearly every documentary involving octocpusses and has a BE narrator. Makes me cringe every time they say it. Never heard an AE speaker use it except in reference to Bond. - UtherSRG 18:57, 18 Nov 2004 (UTC)

I'm neither British nor American, and not an English "speaker", literally. Either you're confusing a funny pronunciation of "pus-es" with "pussies", or I seriously don't get the joke. Femto 19:39, 18 Nov 2004 (UTC)

It's no joke. They may not write it, but they do say it. - UtherSRG 20:18, 18 Nov 2004 (UTC)

Well, we can't leave a reference to an uncitable slang use in a paragraph on how a word is written. Femto 21:18, 18 Nov 2004 (UTC)

Octopussy usages:

[2] - (commented, Femto) A title of a weblog entry, among "I'm an 80s God!" and "Splish splosh"
[3] - A text heading, among creations like "macho mollusc". (Ugh, FortuneCity won't give me the images without tracking personal info)
[4] - An image caption, apparently from a Scandinavian photographer, on a Japan-hosted site!?

- UtherSRG 22:40, 18 Nov 2004 (UTC)

I was hoping for a BBC documentary transcript or something. All I can concede is that the term is sometimes used to refer to octopuses, but it's not mainstream English or in the dictionary, and I can't prove any direct connection to British English. I'm perfectly fine with the current edit though, what do you think? Femto 12:13, 19 Nov 2004 (UTC)

I was hoping for such, too.... but I did the search quickly during class (searching for both cephalopod and octopussy). those were the (at least) minorly promising hits I could grab before I had to close extraneous windows. That all said, I couldn't leave well enough alone and made your link to the Bond movie more explicit. - UtherSRG 12:52, 19 Nov 2004 (UTC)

No prob. And you never know when you'll need a page that explains how to bake a hedgehog. Femto 14:32, 19 Nov 2004 (UTC)

Re: rm bizarrerie - I've reverted because both the Bond name and the term of endearment derive from each other, and they are directly related to the subject of this article. "Octopussy" is a natural association and should be mentioned in a paragraph about words used for octopuses. Femto 13:40, 4 Dec 2004 (UTC)

Re: delete ridiculous facetiousness - see above. I think the facts themselves are appropriate to this article and shouldn't be simply removed with a 'minor' edit. Any suggestions how to make it less of a silly run-on sentence? Shorten it to "Finally, there is Octopussy, a blend name of octopus and pussycat, which is sometimes used as a term of endearment for octopuses."? Femto 13:38, 29 Jan 2005 (UTC)

See also Talk:Octopussy on the derivation of the word. Femto 14:31, 20 Apr 2005 (UTC)

Sorry guys, I deleted the octopussy reference before reading the talk. (DOH!) However, either as a term of endearment or as a character in and title of a Bond movie, I don't find the Octopussy reference to be relevant enough to warrant citing in an article devoted to the animal. Rhodekyll 09:01, 28 January 2006 (UTC)

The reference would be nonnotable if the plural paragraph wasn't there. Though the association comes naturally and it'll likely get included again (I'm not the one who initially added it, for the record). I'd rather keep the one sentence that has seen some development now. Femto 12:39, 28 January 2006 (UTC)

WHY DID THEY REMOVE IT?? TS3 23:36, 13 February 2007 (UTC)

Remove what? The Octopussy reference? Read above. -JC 04:31, 14 February 2007 (UTC)

Disputed

References to "Wells" in this section are to Octopus: Physiology and behaviour of an Advanced Invertebrate by M.J. Wells, Chapman and Hall, London, 1978. (ISBN 0470991976)

Good job finding this information. Now be bold and edit the articles as appropriate. No need to insert {{dubious}} tags throughout unless there is some disagreement here on the talk. I'll try to comment in the secitons below. (As well, I'm going to modify some of your formatting. - UtherSRG 18:25, Jan 3, 2005 (UTC)

Hrm. 1978 is a bit old. I've made some changes and removed the tags. Let's see if we can find something more recent, and I'll see about finding a local copy of Wells. - UtherSRG 03:35, Jan 4, 2005 (UTC)

That was why I didn't just make the changes myself. -- Dominus 14:00, 4 Jan 2005 (UTC)

Blue-Ringed Octopus's rings

According to the article, the blue rings displayed by the Blue-ringed octopus are the product of its chromatophores:

They also have specialized color changing skin cells called chromatophores ... the very poisonous Blue-ringed Octopus becomes bright yellow with blue rings when it is provoked...

However, Wells says that the chromatophores are always in the yellow-red-brown-black range:

By the time the little animals settle out of the plankton, the population of chromatophores has become subdivided into two groups, a very dark set, which can vary from black or red-brown, and a paler series which appears red when contracted and pale orange-yellow in extension. (p. 283)

The chromatophores themselves are all in the yellow-red-brown-black range. (p. 212)

Thus, the blue rings cannot be due to the chromatophores. Wells continues:

Plainly, these two along cannot possibly account for the full range of colours that anoctopus can show. The explanation lies in the possession of two sorts of light-reflecting structure, the iridophores and the leucophores, lying beneath the chromatophores.

The iridophores, not the chromatophores, would appear to be responsible for the blue rings. -- Dominus 17:44, 3 Jan 2005 (UTC)

I suggest adding mention of iridophores and leucophores to the article, and the also checking blue-ringed octopus for other changes needed. - UtherSRG 18:25, Jan 3, 2005 (UTC)

Color Vision

According the the article, octopuses have color vision:

Octopuses ... can easily distinguish among colors and shapes in laboratory experiments. More impressive is that they can remember the shapes and colors and their meanings for up to two years ...

However, according to Wells, octopuses do not have color vision:

Octopus is a colourful animal, capable of rapid colour change. It succeeds in matching its background and it employs colour changes in a range of displays directed at its own kind and at other animals. Prima facie one would expect octopuses to be able to distinguish between colours.

The evidence available nearly all suggests that they cannot. Experiments have included discrimination learning, electroretinogram studies, and an examination of optomotor responses of animals in a striped drum. ... (p. 209)

And later on:

All the available evidence suggests that Octopus is colour-blind. (p.284)

-- Dominus 17:22, 3 Jan 2005 (UTC)

Probably stating something along the lines of noting "their abilities to match their pigmentation to the surrounding color and texture is more phenominal given that they are unable to see in color" would be right. - UtherSRG 18:25, Jan 3, 2005 (UTC)

It also states that

This color-changing ability can also be used to communicate with or warn other octopuses. How do they pull that off if they do not possess color vision? Thenumbereight 22:38, 29 July 2007 (UTC)

Opening Jars

The article says:

An octopus can also learn how to unscrew the lid of a jar with its arms...

However, according to Wells, this is not the case. Wells says:

Crabs can be wrested from containers but the results appear to be achieved by chance and there is little indication that the octopus can learn to deal with the situation more efficiently with practice. The animal approaches and struggles with the apparatus until something happens; if it learns anything as a result of its experience it is only to be more persistent and vigorous. (p. 241)

-- Dominus 17:22, 3 Jan 2005 (UTC)

Perhaps note their trial-and-error learning may not give them a straight-path solution, but that some successes can lead them to find the struggle worthy. - UtherSRG 18:25, Jan 3, 2005 (UTC)

Interesting documents about octopus intelligence and learning can be found here, in case someone wants more background for editing:

In any case the article directly contradicts itself over the jar opening. I don't know which way it should be, but the article should not say that they can learn how to open jars by example and then a few paragraphs later say that they cannot learn how to open jars. --Ignignot June 28, 2005 14:23 (UTC)

Interesting article about defence mechanisms among two species of octopuses; "walking" as camouflage: New Scientist article. -Tim Rhymeless (Er...let's shimmy) 06:05, 27 Mar 2005 (UTC)

(Fixed the NS link.) More noteworthy, I'd like to point out that it also contains a link to an article titled "I spy with my little octopussy eye"! Femto 10:23, 27 Mar 2005 (UTC)

Experiments show that octopuses can not only learn how to open jars to get crabs, but can demonstrate observational learning. An experiement by the Long Marine Laboratory in Santa Cruz in which one octopus can open a jar to get a crab and one can not, if the one that is having problems is shown the other octopus opening the jar, it in turn will be able to open the jar. 24 Aug 2005

Do you have a reference we can all read? - UtherSRG (talk) 09:33, August 25, 2005 (UTC)

Diet

Trying to extend the list of carnivorous animals at Carnivore. Are Octopuses (and squids) exclusively carnivorous??--ZayZayEM 03:27, 7 Apr 2005 (UTC)

Octopuses are exclusively carnivorous. I believe squids are, but I don't know for sure. -- Dominus 02:20, 8 Apr 2005 (UTC)

It would be useful for the article to describe the diet of octopuses (beyond crabs and sharks). Where do they fit in the food chain? --Occamy 13:03, 27 June 2006 (UTC)

I agree, there should be a diet section in this article (Serandolma (talk) 13:15, 29 February 2008 (UTC))

And the diet section has been added by some User:AdidasTrainers. But it doesn't sound quite right, don't you think? I would gladly change it, but I don't know anything about octopus. —Preceding unsigned comment added by 193.219.160.131 (talk) 11:47, 3 May 2008 (UTC)

Needed Additions

I'll try to add all these myself eventually, but if anyone already knows the answers (in other words, if you know more than I do now), please put in some of this stuff:

The suborders listed here are "Cirrina" and "Incirrina", but I think that "Cirrata" and "Incirrata" are more common. Does anyone know? I believe they are equivalent, but maybe that's not even right.

There is nothing in the page about reproduction of octopuses. Note that there is a common myth even among semi-experts that octopuses reproduce with the aid of one of their arms (true) and that it breaks off in the process (false). Only one (or perhaps a few) species actually lose their arm in reproduction.

Contrary to what the introductory information says, octopuses of the cirrata suborder do have internal shells. - Nabarry

"Cirrina" and "Incirrina" are how they are listed in Current classification of Recent Cephalopoda, which is what CephBase and WP:CEPH's taxonomy is based off of.

I've added the distinction of the internal shell for the cirrate octos into the article, and I'll leave it to you to add in the reproduction information, although I may do it later if you don't get to it.

On other matters: Please sign your comments with ~~~~ so we know who is in the discussion, and consider registering a username. - UtherSRG 11:40, Apr 26, 2005 (UTC)

Thanks for suggestions and comments. I am new.

I see that the classification website you listed uses Cirrina; also that website references the Integrated Taxonomic Information System, which also lists the suborder as Cirrina. But Cirrata seems to be used pretty frequently: more pages come up on Google for Cirrata than for Cirrina. Do you know why this might be?

I emailed Dr. James Wood from the Cephalopod Page (he uses Cirrata) and asked him if he knows the difference between the two. If you happen to know, it would be nice to put in a note in the classification. Otherwise I'll add it when he answers, if he knows.

I think that even if Cirrata is an outmoded form, it seems to be used often enough that it deserves mention as a form that used to be common.

Nabarry 12:50 PM, April 26, 2005 (PST)

Cirrina Page

I just created a page for Cirrina. It is actually more of a sub-stub, but I wanted to get it started. I'll add more tonight, and more throughout the week if I can find time.

I also removed the following sentence from the Octopus article: "The octopuses in the Cirrina suborder have two fins and an internal shell." I felt that it did not really fit into the paragraph.

I think that there must be a far better way of referencing the Cirrina page than the way I did it (footnote referring to the bottom of the paragraph). But I do think that since most people only know about Incirrina, Cirrina belongs elsewhere. For example, these sentences in the Octopus article are pretty neat: "A beak, similar in shape to a parrot's beak, is their only hard part. This enables them to squeeze through very narrow slits between underwater rocks, which is very helpful when they are fleeing from morays or other predating fish." But they aren't true of the Cirrina. The Cirrina have an internal shell and thus cannot squeeze through narrow slits and all that.

Let me know what you guys think; I'm not set on keeping Cirrina info off the Octopus page, since they are certainly octopuses. I just think it's easier this way.

Nabarry 05:38, 2 May 2005 (UTC)

Cirrata and Incirrata are the proper terms for these groups. More information about the relationships between octopuses and other cephalopods can be found on the "Tree of Life" web pages (http://tolweb.org/tree?group=Cephalopoda)

The Colossal Octopus

What of the colossal octopus? I think it at least needs mention. http://unmuseum.mus.pa.us/coloct.htm Joelloughead 28 June 2005 13:51 (UTC)

No, it's fictional. - UtherSRG June 29, 2005 18:30 (UTC)

Perhaps it needs mention as being fictional. -- Dominus 30 June 2005 06:55 (UTC)

I don't believe that is so. Not everything fictionally based off of something real should be mentioned in an article about the real thing. Perhaps an article on the Unmuseum could include something about the colossal octopus, with a link to octopus to provide real octopus information, though. - UtherSRG June 30, 2005 10:49 (UTC)

Here's another link to some information about the possible creature. Read it, the evidence is intriguing at the very least. I really think that it's credible enough to deserve mention as a bit of curiousity. Joelloughead 6 July 2005 15:59 (UTC)

Out of water

The article mentions octopuses boarding ships and escaping from their aquariums. How long can they survive out of water? Can they breathe air?

I had a problem with that line too, because it said that octopuses have boarded ships in order to get crabs and eat them. Tempshill 22:06, 21 October 2005 (UTC)

Why else would they board the ships? They sense tasty crabs, and want to eat them. Octopuses can survive for a while outside of water, especially if they remain damp. As long as they can hold their breath, anyway. -JC 05:02, 10 June 2006 (UTC)

Duct tape boxes vs. no mental imagery of objects

As a result, the octopus does not seem to form a mental image of the overall shape of the object it is handling. It can detect local texture variations, but cannot integrate the information into a larger picture.

Can this be reconciled with the octopus learning by observation how to open a duct-taped box? Tempshill 22:06, 21 October 2005 (UTC)

Sure. See the quote above from Wells, which says, in part,

The animal approaches and struggles with the apparatus until something happens; if it learns anything as a result of its experience it is only to be more persistent and vigorous. (p. 241)

-- Dominus 23:42, 23 October 2005 (UTC)

The other thing to note is that the citation for that remark is from BBC science reporting, which is notoriously sensationalistic and unreliable.

For example, some time ago they ran an article on mutant three-headed frogs and quoted their "wildlife expert" as being completely baffled. But the picture clearly showed what was obviously three frogs in a big frog pile.

So just because the BBC says that octopuses can learn to open boxes from observation, doesn't mean it's so. -- Dominus 04:11, 29 October 2005 (UTC)

Regeneration after autotomy?

Autotomy (to which I've just added a brief mention of the octopus) says that autotomizing lizards regenerate a cartilaginous tail after losing their original one. Do octpuses regenerate a limb, imperfect or otherwise, after losing one self-defensively? I'm guessing that post-coitally they do not do so as we are told the males die within months of mating. Sharkford 19:13, 18 November 2005 (UTC)

Yes- the autotomized arm grows back. (CLH @ UCB)

Carmouflage

I find octopus' carmouflage techniques very interesting, yet there is little said about this in the article. May someone contribute additional facts about octopus carmouflage? --Abdull 13:51, 25 November 2005 (UTC)

That google video link to camouflage is the same as the one in the link above it. It should be deleted because it's redundant and adds no additional information. You'll learn more if you get it from the author's source.

This is an archive of past discussions about Octopus. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page.

Archive 1

Archive 2

Octopus (genus)

The Octopus (genus) page should not redirect back to here. How is that changed? —The preceding unsigned comment was added by Eco mate (talk • contribs) .

I'll delete the redirect. - UtherSRG (talk) 11:06, 24 April 2006 (UTC)

Rotating beak?

I've heard that octopus beaks can rotate - even indefinitely. Is there any truth in that? Thanks. 81.101.132.230 13:33, 29 April 2006 (UTC)

I've never heard this. - UtherSRG (talk) 21:08, 29 April 2006 (UTC)

Seems unlikely, according to this page: http://pharyngula.org/index/weblog/print/2986/ Of particular relevance and entertainment:

"The beak itself is made up of a combination of chitin (a carbohydrate, the same stuff that makes up insect exoskeletons) and proteins. The buccal mass is a roughly spherical lump of tissues with a fair amount of motility and independence—the beak can be swiveled about at various angles, can protrude and retract, and the whole mass can be dissected out and still function surprisingly well. In at least some species, the isolated buccal mass will continue to chomp away for up to two hours after it's removed. It's like an autonomous set of choppers.

SleekWeasel 01:48, 20 September 2006 (UTC)

Surgery forbidden?

In many countries, including the United States and the United Kingdom, octopuses are on the list of experimental animals on which surgery may not be performed without anesthesia. ‹The template Talkfact is being considered for merging.› ^{[citation needed]}

I removed the above from the article. US Federal law 7 USC 54[5] doesn't seem to mention octopuses. If there's another law, please feel free to add it back, with a proper citation. --KJ 13:15, 7 June 2006 (UTC)

Thanks. I've tentatively put back the paragraph, and added a cite that points to the text of the UK law, which does specifically include octopuses. I have also sent an inquiry to the animal care group at the U.S. department of agriculture to ask if there are any analogous laws or regulations in the US. I will update the paragraph further when I receive a reply or if I discover any more information. -- Dominus 21:04, 7 June 2006 (UTC)

Thank you very much. :D —The preceding unsigned comment was added by Kjoonlee (talk • contribs) .

Detroit Red Wings

Oddly enough this appears to be true, though I think it's borderline notable to the article. Femto 11:46, 29 June 2006 (UTC)

I have no doubt about the veracity of the claim. I don't believe it belongs in this issue. It's a bit of fact much better suited to a hockey article. - UtherSRG (talk) 12:01, 29 June 2006 (UTC)

Reference Needed

The reference to _Fowler's Modern English Usage_ requires the edition and publication date, since different versions of Fowler's say different things about the plural forms of octopus. —The preceding unsigned comment was added by 71.141.243.216 (talk • contribs) . - UtherSRG (talk) 17:47, 9 August 2006 (UTC)

Does it? If you know that, then you must have access to the citation information, so please add it. - UtherSRG (talk) 17:47, 9 August 2006 (UTC)

Attacks on humans?

Are there any documented cases of octopus attacks on humans? After watching the linked video of an octopus stalking then catching a shark, I can't help but relate to the shark's experience... a snorkeler swimming over an octopus would have less chance than that shark. Then again, I recall seeing footage of a marine biologist swimming in the ocean with the giant octopuses in San Francisco Bay, and thinking that they must have some sort of respect for humans as compared to sharks (not unlike dolphins, I guess?), because they could have ripped his head off if they wanted to, but instead seemed happy to just cavort with him. Anyway... anyone have any data? Thanks. — Epastore 15:17, 13 September 2006 (UTC)

...is that a no? :) — Epastore 00:42, 7 October 2006 (UTC)

I found this in about five seconds by doing Google search for "octopus attacks human". -- Dominus 16:38, 7 October 2006 (UTC)

Interesting (and scary... and btw the video has since been removed for copyright violation). Anyway, that looks more like an octopus defending its territory than feeding. While it is an instance of an octopus attacking a human, I was looking more specifically for cases of one being aggressive to humans, rather than defensive. (Not that I'd like to be in that diver's situation!) — Epastore 17:12, 19 October 2006 (UTC)

There have not been any well-documented cases of an octopus attacking a human out of agression. There are numerous "big fish" stories about tentacled marine animals attacking and sinking anything from dingies to full-sized sailing ships, the latter of which can probably be dismissed as fancy. However, hunting squid in large numbers enter a sort of frenzy if disturbed and may generate enough turbulence with their thrashing to capsize small boats. Please note that I'm not saying if you poke an octopus long enough that it won't bite you; they just don't go looking for innocent divers to chew on. --Wyrmfire 22:04, 25 October 2006 (UTC)

Sex!

So "When octopuses reproduce, males use a specialized arm called a hectocotylus to insert spermatophores (packets of sperm) into the female's mantle cavity." Oooh, baby. But quite what is he inserting the sp********ore into? The syphon? That's surely going to make her sneeze. Is there a special girly part to receive it? Thankee! SleekWeasel 01:30, 20 September 2006 (UTC)

Syphons

While I'm asking stupid questions, so... there's a syphon, but I can't tell whether it normally pokes out on the left hand side or the right. I see pictures with either. Any ideas? My guess is that it's really ventral and merely pokes out to one side or the other, but the interweb doesn't seem to know. SleekWeasel 01:30, 20 September 2006 (UTC)

My edits

I removed "(the most intelligent of any of the invertebrates,) with their intelligence supposedly comparable to that of the average housecat." until it is sourced. It seems to contradict both various sources and issues that have been raised on this talk page. As a whole, I introduced a more restrained attitude towards octopus intelligence. User:Dominus has argued for the same on this talk page, but for some reason, he doesn't seem to have used the source he has been quoting in the actual article. --194.145.161.227 17:16, 12 October 2006 (UTC)

Autophagy/Feeding

The bit about octopuses eating their own limbs is interesting and useful, but I don't think it's in the right place. It's currently in the "Intelligence" section, perhaps because the phenomenon has neurological causes. I think the autophagy bit should be moved, but I don't think there's currently a more appropriate section for it. However, I think the article could use a section on feeding, and if that section were to be added, that would be a good spot for the autophagy description. Thoughts? Schi 19:31, 18 October 2006 (UTC)

Reproduction questions

From the Reproduction section:

After the eggs hatch, the young larval octopuses must spend a period of time drifting in clouds of plankton, where they feed on copepods, larval crabs and larval seastars until they are ready to sink down to the bottom of the ocean, where the cycle repeats itself.

(Emphases added.) What cycle is this? It sounds like they're going to drift in the plankton cloud and sink down again, but it's written as if the cycle repeats itself at the bottom of the ocean. It seems to me that the description skips the step of how they drift back up into the plankton cloud. Schi 23:19, 18 October 2006 (UTC)

I think it's suggesting that at that point, they're grown up octopuses and find a mate and lay eggs of their own. -JC 04:27, 14 February 2007 (UTC)

A different type of intelligence?

What I had heard was that the octopus followed a hunting strategy of sitting and waiting. And a case can be made that this favorably compares to a strategy of energetically searching and burning a lot of calories in the process. Kind of like playing Texas Hold’em poker, you can either follow a strategy of trying to energetically bluff or you can sit back and wait for a good hand.

But, the article is causing me to question this. Apparently, octopuses do spend considerable time roaming in search of prey.

So, maybe different in a different way. A lot of neurons are in the arms, the suckers have taste receptors, that information goes upward, being distilled and organized along the way I imagine. Analogous to our dominant sense, the sense of sight, the information is processed and refined as it makes the way from rods/cones to brain. We don’t see the blind spot of each eye. And interestingly, often we do not see something that we don’t expect to see.

And then the fact that the octopus doesn’t have the proprioceptive sense, bodily position, which gymnasts have exquisitely and all humans have to a pretty good extent. So an octopus does not have this. That must make for a rather different existense and a different internal experience. FriendlyRiverOtter 08:35, 18 March 2007 (UTC)

While this doesn't directly answer your questions, you may be interested to note the article on cephalopod intelligence. — Epastore 05:10, 23 March 2007 (UTC)

Plural

I believe that the correct plural form for more than one octopus, although not of popular usage, is actually octopodes, while "octopuses" and "octopi" are used. —The preceding unsigned comment was added by 71.125.32.185 (talk) 02:23, 6 April 2007 (UTC).

See above Rklawton 12:25, 21 April 2007 (UTC)

I looked it up. In a dictionary. Either is correct, which makes it pointless to edit-war over it. Everyone who reverts the plural form of this word- in either direction- is now officially lame, lame, lame. -FisherQueen (talk · contribs) 18:52, 12 December 2007 (UTC)

Which is which?

Hi, I'm only a kid so I can't understand what all those big words mean. I do know there are two types of octopai, one I call "big head", which has a big head and its eyes on the lower part, and one I call "big nose", which has that big thing in front of their eyes, that looks like a nose but clearly isn't (and I don't know what it is). So could someone identify both of those please? 68.164.94.6 00:03, 26 July 2007 (UTC)

I only know of one kind of octopus. Perhaps what you see as a "nose" is merely a portion of the octopus's mantle? Remember that they are very pliable creatures. Some pictures would help. -JC 20:20, 26 July 2007 (UTC)

Documented Human Attacks (Apocryphal)

I will start looking into it, but I know for a fact there are well-documented cases of octopus attacks on humans(yes many are apocryphal but some are not; all the ones I have seen are in self-defense of course). I do no want to encourage misconceptions or start a panic against some of the most interesting creatures in existence, but it certainly helps shape the inscrutability of the species. Does anyone have any references off the top of their heads? I think it would make a fascinating inclusion to the article 67.88.117.162 08:03, 23 August 2007 (UTC)

Irrelevant link

In the "As pets" section, there's a wikilink to the candy company Just Born. Much as I enjoy the fundamental interconnectedness of all things, do we really need this? It could also be construed as advertising. —Preceding unsigned comment added by 69.226.16.188 (talk) 22:06, 5 April 2008 (UTC)

Good catch. I've removed the wikilink. Mgiganteus1 (talk) 02:14, 6 April 2008 (UTC)

Feet, not Legs

I had changed "eight-legs" to "eight-feet", someone has changed it back. Please don't. Pod- means "foot" in Ancient Greek, not leg. —Preceding unsigned comment added by Ekindedeoglu (talk • contribs) 18:53, 13 April 2008 (UTC)

ASPA act 1986

Should it be mentioned that Octopus vulgaris are the only invertebrates that are included in the Animals (scientific procedures) act 1986 (UK)? Not sure where to put this info. here is the act in question, the relevant section is section 1(1) --Dylan2106 (talk) 10:26, 16 April 2008 (UTC)

ignore the above... It is in the article... --82.35.74.212 (talk) 20:16, 20 April 2008 (UTC)

Brething / Pets Questions

It says they can "escape captivity" and "move between tide pools". Exactly how do they survive during this time? Do they have some other breathing method apart from gills, or do they simply not breath during this time? How long do they survive out of water?

Also, the "as pets" section is not very informative. It says they can be difficult to keep as pets, but not why, other than that they can escape. I assume they also eat other creatures in the tank. I think they'd make cool pets (compared to fish), so I'd be interested to find more info, but this section is lacking. Maybe not enough people have them as pets for this section to contain good info. 74.14.122.167 (talk) 04:29, 10 May 2008 (UTC)

Size Matters!

Fascinating as all the Greek and Latin arguments are, do we have a size range for these creatures? Seems like a rather sophomoric thing to ask, in light of all the fascinating "tentacles, limbs or arms" and "Greek or Latin plurals" discussions, but conspicuous by its absence is a reference to just how big these creatures can get, or how small. Can someone who knows add this information? PatrickLMT (talk) 10:32, 20 May 2008 (UTC)

The largest octopus is probably the North Pacific Giant Octopus; that article has several references supporting this claim. The smallest octopus is a zooplankton that just came out of the egg. Feel free to add details; it's your article too. -- Dominus (talk) 13:39, 20 May 2008 (UTC)

I've added a section on size. Let me know what you think. Mgiganteus1 (talk) 04:59, 22 May 2008 (UTC)

What about smallest octopuses? Octopus octopus minor minor (the nakji in sannakji) can be eaten whole. Octopus ocellatus is probably similar as well. Are there any smaller species? --Kjoonlee 06:09, 22 May 2008 (UTC)

I have often heard that Octopus micropyrsus as the smallest octopus. They only get to be a few centimeters long. Taollan82 (talk) 05:52, 11 June 2008 (UTC)

WikiProject Food and drink Tagging

This article talk page was automatically added with {{WikiProject Food and drink}} banner as it falls under Category:Food or one of its subcategories. If you find this addition an error, Kindly undo the changes and update the inappropriate categories if needed. The bot was instructed to tagg these articles upon consenus from WikiProject Food and drink. You can find the related request for tagging here . Maximum and careful attention was done to avoid any wrongly tagging any categories , but mistakes may happen... If you have concerns , please inform on the project talk page -- TinucherianBot (talk) 03:00, 4 July 2008 (UTC)

Anonymous Question

HOW DOES AN OCTOPUS EAT??? answer me that. please. —The preceding unsigned comment was added by 24.12.193.243 (talk • contribs) .

Well, generally using its mouth. There surely are some videos out there of octopuses eating things like tasty crabs or something, isn't there? -JC 07:09, 21 July 2006 (UTC)

It grabs something with its tentacles, a little like a boa constrictor, and draws the food towards its beak which is sited where all its tentacles meet. It uses its beak to nibble or tear chunks off. If it's a shellfish, it uses its toothed tongue - called a radula - to drill through the shell, or a couple of other techniques to get at the meat. SleekWeasel 01:51, 20 September 2006 (UTC)

SO THE OCTOPUS EATS ITS FOOD ALIVE?? —Preceding unsigned comment added by 66.82.9.88 (talk) 22:57, 8 June 2008 (UTC)

I'm sure whatever it preys upon will be dead before it is completey eaten :)Almighty Rajah (talk) 19:02, 27 July 2008 (UTC)

Top aquaculture producer?

Is Spain the industry leader in octopus aquaculture with 16 tonnes of catch in 2005? Anwar (talk) 13:44, 12 July 2008 (UTC)

Re:unnecessary changes

To quote from WP:MOS:

This Manual of Style, often abbreviated MoS, is a style guide for Wikipedia articles. One way of presenting information is often just as good as another, but consistency promotes professionalism, simplicity and greater cohesion in Wikipedia articles. An overriding principle is that style and formatting should be applied consistently throughout an article, unless there is a good reason to do otherwise (except in direct quotations, where the original text is generally preserved).

If the Manual of Style does not specify a preferred usage, discuss your issues on the talk page of this manual. The menu to the right contains links to Manual of Style pages that explore topics in greater detail.

It is inappropriate for an editor to change an article from one style to another unless there is a substantial reason to do so; for example, it is unacceptable to change from American to British spelling unless the article concerns a British topic. Edit warring over optional styles is unacceptable. If an article has been stable in a given style, it should not be converted without a reason that goes beyond mere choice of style. When it is unclear whether an article has been stable, defer to the style used by the first major contributor.

The original style would remain. JNW (talk) 03:57, 14 August 2008 (UTC)

This elaboration, from Apostrophe:

Singular nouns ending with an "s" or "z" sound

This subsection deals with singular nouns pronounced with a sibilant sound at the end: /s/ or /z/. The spelling of these ends with -s, -se, -z, -ze, or -ce. Traditionally it was more common to require and many respected sources still do require that practically all singular nouns, including those ending with a sibilant sound, have possessive forms with an extra s after the apostrophe. Examples include the Modern Language Association, The Elements of Style, and The Economist.[5] Such sources would demand possessive singulars like these: Senator Jones's umbrella; Mephistopheles's cat. However, many modern writers omit the extra s. Some respected style guides such as the Chicago Manual of Style recommend the traditional practice but say that both are correct.[6]

The addition of an extra 's' is traditional, and supported by reliable sources. Of course, the alternative works, too, and is sometimes preferable. The issue here is that, as stated above, short of a compelling reason for changing a previously accepted usage, the original version is respected. JNW (talk) 22:04, 14 August 2008 (UTC)

Sadly, we must acknowledge that although WP:MOS aims to serve well in the community, it is ultimately bollocks. An honest, unbiased review of WP:MOS will reveal that it simply takes established, ages-old conventions of the English language and assigns these laws of linguistics unlimited subjectivity. If we have any respect for English, then we must use caution when applying WP:MOS to an article. More often than not, WP:MOS is a slap in the face to the long-lasting standards of use of the written English tongue. To emphasize, it is of particular note that the article for Jesus uses the possessive form Jesus' rather than Jesus's. And rightly so. Packed Lunch (talk) 23:09, 14 September 2008 (UTC)

By all means raise your concerns on the talk page for WP:MOS. Policies can be modified through informed, and mutually respectful, discussion. JNW (talk) 00:29, 15 September 2008 (UTC)

Six arms and two legs

According to http://www.msnbc.msn.com/id/26197656 and http://www.telegraph.co.uk/news/newstopics/howaboutthat/2547597/Octopuses-have-two-legs-and-six-arms.html , octipi's eight arms can be divide into six arms and two arms. Should we include this into the article? --Yvesnimmo (talk) 18:28, 14 August 2008 (UTC)

I really don't think the issue of octopuses having "six arms and two legs" should be included in this article. 1) The has not yet been peer-reviewed, and while it has been cited in many news articles, because this information is the type that is generally peer-reviewed before being accpeted by the scientific community (and presumably will according to several articles) I think the inclusion of this information is a borderline violation of WP:NOR. 2) The only outlet of this information is popular news, which often overstates or misstates scientific work. 3) The way these news articles are worded are often technically incorrect. Octopuses have eight arms. Each is developmentally equivalent. What these news articles suggest is that a behavioral difference in how they are used, leading that "We”ve found that octopuses 'effectively' have six arms and two legs" (http://www.thaindian.com/newsportal/south-asia/octopuses-have-only-six-arms-the-other-two-are-actually-legs_10083357.html), a very large difference from octopuses anatomically having six arms and two legs and the article now states. Additionally some researchers on this project have shown a lack on knowledge in octopus anatomy and physiology, stating certain octopuses preferences between "red" and "yellow" (http://afp.google.com/article/ALeqM5j1MNsYD_Llq2sXaywJpQoul6ojdw). Octopuses are colorblind, and a finding otherwise would be very big news indeed. In conclusion I believe this work should pass muster in the peer review system before being included in this article. Unless there are major objections in the next two days, I will remove the references to "six arms, two legs" from this article. Taollan82 (talk) 23:54, 25 August 2008 (UTC)

Wow, and the idiots who wrote the MSNBC article think octopuses have tentacles. Please do remove it by undoing back to the last good version. Reywas92 ^Talk 00:17, 26 August 2008 (UTC)

Octopuses

Octopuses are wonderful intelligent eight armed cephalopods. They are fascinating creatures and should be studied well by marine biologists. —Preceding unsigned comment added by 86.43.163.122 (talk) 19:56, 16 September 2008 (UTC)

Link

Could somebody who isnt restricted please put a link to the Cephalopod ink page in a suitable place? near defense, perhaps, or under see also? Thanks :-) K-22-22 (talk) 12:04, 2 December 2008 (UTC)

I linked the first use of the word "ink" in the "defense' section. Thanks for the suggestion. I'm sorry that you were not able to edit the article yourself. —Dominus 17:00, 2 December 2008 (UTC)

Thanks :-) I can understand why it's blocked - some people seem to refuse to admit that the plural of octopus is not octopi. K-22-22 (talk) 20:44, 2 December 2008 (UTC)

Semi-protection..

Considering the amount of vandalism this article receives, perhaps semi-protection would be a good idea? Debolaz 18:26, 29 March 2007 (UTC)

Done. Wow! You guys have been great at keeping this article clean. Take a week off to edit something more fun! Rklawton 23:45, 29 March 2007 (UTC)

This article is still being vandalised regularly. Is it possible to restrict the article to being edited only by people with accounts active for 4+ days? That would save people a lot of time... K-22-22 (talk) 10:42, 10 December 2008 (UTC)

Vision

The research published recently should be included under octopus' vision. It's interesting to note that they see standard TV as a series of still images, but process HDTV as animated.

source: http://www.smh.com.au/cgi-bin/common/popupPrintArticle.pl?path=/articles/2008/12/21/1229794225193.html —Preceding unsigned comment added by Jacob.roecker (talk • contribs) 04:36, 22 December 2008 (UTC)

Vandalism target

Vandals have been striking this page. Hope we can keep an eye on it. Wbroun 17:48, 6 July 2007 (UTC)

This page is regularly vandalised. Is it possible to protect it further? K-22-22 (talk) 14:56, 12 January 2009 (UTC)

Crazy theory about Octopi

It has been proven that Octopi die a few months after reproducing. I have a theory (unbelievably by piers have accepted this and my teacher) that if you cut their sex cells (Gametes) off would the octopi live longer?

I understand that female octopi can live a little longer.

Can anyone clarify my theory?

Danielthomas 44 (talk) 14:28, 24 March 2009 (UTC)

Simple answer...No. There was some paper published thirty years ago showing that it is the the optic gland (a lobe of the brain) that controls reproductive maturation and if you disrupt this you could potentially prevent death (this doesn't work so well in real life). This is separate from the ovaries and testes that produce the gametes. It is the ovaries and testes in mammals, not the gametes themselves that produce sex-specific hormones (in general terms). If you are interested in more, check out these two papers:

Wells, MJ and Wells, J. (1977) Optic glands and the endocrinology of reproduction. Sym Zool Soc Lond 38:525-540.

Wodinsky, J. (1977) Hormonal Inhibition of Feeding and Death in Octopus: Control by Optic Gland Secretion. Science 198:948-951

Taollan82 (talk) 02:56, 27 March 2009 (UTC)

An octopus escaping through a crack?

An anonymous user recently changed the caption on this picture from "An octopus escaping an aquarium through a thin crack" to "The reflection in the glass gives the illusion of an octopus escaping through a crack." Another user changed it back. I looked closely at the picture and I think the anonymous user is correct.

On the left side of the image, there are what appear to be two horizontal gray bars with a crack in between through which the octopus is passing. If you look at the leftmost edge of the "crack", I think you can see the image of the bottom "bar" superimposed on the octopus. I think this is because the bottom "bar" is actually a reflection of the top "bar" in the outside of the glass. Notice that although the top "bar" continues all the way to the right-hand side of the picture, the bottom "bar" vanishes partway across.

Also notice that the octopus has its ventral side facing the glass, as you would expect it to if it were inside the tank. If it were escaping the tank, you would expect to see the dorsal surface outside the tank.

I interpret the picture this way: The octopus is entirely inside the glass-walled tank, with part of its body attached to the wall and the rest occluded by the visible part. The viewer is outside the tank. The top gray "bar" is not a vertical surface but a horizontal one, perhaps a ceiling of some sort, extending away from the glass, toward the viewer. The bottom "bar" is an illusion, a reflection of the top "bar", whatever it is, in the outside of the glass. I wish I understood the top bar better.

If nobody objects, I will change the caption to say something like "the reflection in the glass gives the illusion of an octopus escaping through a crack." —Dominus (talk) 02:49, 30 March 2009 (UTC)

An interesting hypothesis. I don't find that the answer is clear. If the bottom barlike thing is a reflection, why don't we see it reflected along the body of the octopus as well? In fact at the extreme upper left portion of the octopus, one *can* see both the barlike thing and the octopus, as if both images are overlaid. But another explanation for this might be that since octopus bodies are known to be semi-transparent, and at the upper right of the octopus, its body thickness in the direction of the viewer is quite thin, one may be seeing an actual bar through the octopus's body.

Another reason I'm not yet convinced is that the fine stipplings of the two barlike things don't seem to match; if one were a reflection of the other, of course, all details would match. So I just don't know. Is it possible to determine who contributed this photo and ask them what they know about it?Daqu (talk) 19:36, 30 March 2009 (UTC)

Well, take a look at this version -- just with the color tweaked. Doesn't seem to be a reflection at all. --jpgordon^∇∆∇∆ 21:47, 30 March 2009 (UTC)

File:Octotweak.jpg

Color tweaked

I think your tweaked version shows even more clearly that it is a reflection. Look at the left end of the lower bar. You can see through it!

You can also see a reflection of the camera flash in the "crack" in your tweaked vresion. This would be impossible if it really were a crack; in my model it is just the topmost part of the glass. I now think the top "bar" is actually a bezel around the edge of the glass, coming out at the viewer at a 45-degree angle. This is typical in aquariums.

As for the fine stippling, that's caused by light reflecting off of small features in the metal; you would expect it to appear different if viewed from another angle, as in a reflection. But there is a small white scratch or paint mark toward the left end of the top bar, which is identical in the reflection.

But I think Daqu is right; we should ask the person who took the picture. I did this here. I hope he speaks English, but I don't have much hope. —Dominus (talk) 03:57, 31 March 2009 (UTC)

Also, I have just noticed that he has not edited on Commons since July 2008, and only once since June 2007. So don't hold your breath waiting for a reply. —Dominus (talk) 04:54, 1 April 2009 (UTC)

As I pointed out above, octopus bodies are semi-transparent, which could explain why one can see the barlike thing through the octopus where its body is thin in the direction of the line of sight. But it's becoming quite clear that they don't teach how to think logically in Troy, NY.Daqu (talk) 07:48, 1 April 2009 (UTC)

After reading the above, I'm convinced the octopus is inside the tank. The lower "bar" does not continue on the right side as one would expect and appears to be a reflection of the upper "bar", which seems to be angled as Dominus suggests. It's well documented that octopuses can escape from home aquariums, but the file name suggests this photo was taken in a public aquarium. Finally, I'd expect the moist skin of the octopus to reflect much of the camera's flash if it was indeed on the outside of the glass. mgiganteus1 (talk) 08:08, 1 April 2009 (UTC)

I've commented it out of the article as it becomes a very ordinary image lacking in encyclopedic value if it's not showing an actual escape attempt. I was meaning to trim that section anyway, as it was pretty crowded with images. mgiganteus1 (talk) 08:21, 1 April 2009 (UTC)

Auto-archiving okay?

This page is getting quite long. I would like to arrange to have MiszaBot archive old threads automatically. The robot would move threads to a series of archive pages when they had been inactive for a certain amount of time, say one year. It starts a new archive page automatically when the old one gets too big. Archives would be at pages Talk:Octopus/Archive 2 and similar. The robot would always leave at least the most recent 15 threads on the main talk page.

I have been using this system on my own user talk page for some time; it is also used by Wikiproject Mathematics. Does anyone object? Does anyone have different preferences for the robot's configuration? —Dominus (talk) 02:56, 30 March 2009 (UTC)

There was no objection here, so I've set this up. The configuration looks like this:

{{User:MiszaBot/config |counter = 1 |minthreadsleft = 15 |algo = old(365d) |maxarchivesize = 250K |archive = Talk:Octopus/Archive %(counter)d }}

A detailed explanation of what this means is here. In short, it is as I described above: if there are more than 15 threads on this page, then the bot will remove excess threads that have not been posted to for one year. The removed threads will be placed at a series of subpages of this one, starting with the existing Talk:Octopus/Archive 1 page, and then move on to Talk:Octopus/Archive 2 and so forth. It will start a new page whenever the previous one reaches 250K. The current archive is only 50K, so this will not happen for some time.

I hope this is acceptable to everyone. We can, of course, shut it off again at any time. —Dominus (talk) 18:59, 2 April 2009 (UTC)

The inner mental life of octopuses

The middle paragraph of the Sensation section contains this passage:

"[T]he octopus has a very poor proprioceptive sense. The tension receptors are not sufficient for the octopus brain to determine the position of the octopus' body or arms. (It is not clear that the octopus brain would be capable of processing the large amount of information that this would require; the flexibility of an octopus' arms is much greater than that of the limbs of vertebrates, which devote large areas of cerebral cortex to the processing of proprioceptive inputs.) As a result, the octopus does not possess stereognosis; that is, it does not form a mental image of the overall shape of the object it is handling. It can detect local texture variations, but cannot integrate the information into a larger picture."

I find the assertions 1) "the octopus has a very poor proprioceptive sense" and 2) "it does not form a mental image of the overall shape of the object it is handling" to be extremely dubious. And even if they turn out to be true, it strikes me as impossible for any researcher to determine their truth, because they concern the inner mental life of the octopus.

Proprioceptive sense is knowing the relative positions of the parts of one's body. Considering the wide variety of shapes that the octopus can configure its body in, as the need arises -- for camouflage or for capturing prey (see, for example, that video of an octopus capturing a shark), the octopus must have, on some level, a very fine-tuned sense of its body's position . . . as well as how to rapidly change it to another position when convenient to do so.

And the fact that octopuses can solve complex problems like how to open a jar reveals that an octopus must have, on some level, an excellent "mental image of the overall shape of the object it is handling".

Just on what level of consciousness these awarenesses take place is an issue that is far beyond science's current ability to determine. Surely we currently have no idea just what kinds of levels of consciousness an octopus even has!

For these reasons I would recommend removing these statements from the article . . . or at the very least express them in the form "Some researchers believe . . ." rather than as statements of absolute fact.

Unfortunately, I cannot find a copy of the book that the article uses as a citation for these facts (it is currently sold by the largest online bookseller for U.S.$800, so must be fairly rare at this point).Daqu (talk) 18:43, 27 March 2009 (UTC)

The statement "the octopus has a very poor proprioceptive sense" does not concern the octopus's inner life; it concerns its sensations. I presume that you would have no trouble with a claim that a worm has no sense of sight, based on the fact that it has no eyes. Wells's statement about the octopus's proprioceptive sense is analogous, based on extensive analysis of the structure of its nervous system and on behavioral experiments. Your arguments about the octopus's need for a proprioceptive sense are interesting, but irrelevant, since you are not actually an octopus expert. The octopus often does know the position of its body, not through proprioception, but by looking at it, as experiments with blinded octopuses have shown.

The discussion of the octopus's failure to form mental images is based on extensive experiments to discover whether octopuses could be taught to distinguish objects by their shape as they do by texture. You may object to the phrasing; maybe the octopus forms a mental image of the objects but is unable to use the information effectively, or maybe it chooses not to; who knows? But this is a point of metaphysics, not biology, and at most a minor change of wording is required in this article.

(Wells, by the way, strongly disputes the claim that octopuses can learn to open jars; he states that although they do sometimes open jars, it is always by manipulating the jar essentially at random until they get lucky. The only counterclaim in this article is cited to the BBC, which has notoriously bad science reporting.)

There is a larger point here. You are arguing with claims from Martin John Wells, an eminent biologist, who spent years investigating octopus behavior and neurology. On the other hand, your arguments are stuff you made up out of your head. You find the claims dubious because you can't imagine how they could be substantiated. But this does not say much about the claims; it only shows that you are not able to imagine enough things.

Your personal doubt is not sufficient reason to change the article or to present its claims differently. Wikipedia is reporting information from a reliable source. The source is old, and may be out of date, but you have not argued that. While it would be appropriate to weaken or even remove the claim in the article if another equally reliable source were found that disagreed with the claim, you are not such a source, and you have presented no evidence at all that the article not exactly correct.

In short, although you can make plausible-sounding guesses, you don't actually know anything about octopuses. So why not do some research and come back later with reliable sources? —Dominus (talk) 19:46, 27 March 2009 (UTC)

I agree with Dominus. Personal incredulitiy is not grounds for removal of a cited fact. Furthermore, proprioception is relatively easily tested. Also, should you wish to read up on the point, I would recommend "Brain and Behaviour in Cephalopods" (I think its cited in the cephalopod ink article, see there for details <EDIT: it isn't, so see here>) by the same author, the late Martin J. Wells.

Proprioceptivity in limbs relies on a number of mental (automatic) calculations using an array of information from the limbs. Humans and other vertebrates can do this with relative ease because the calculations can be performed using a a very simple model, because we have bones and joints, which restricts movement to a number of planes. We need therefore only process a small amount of data. The octopus or other cephalopod (indisputably) doesn't have bones and to calculate where their limbs are at any one time requires the processing of more information than their brain can handle. K-22-22 (talk) 22:46, 27 March 2009 (UTC)

I quote from Dominus: "The statement 'the octopus has a very poor proprioceptive sense' does not concern the octopus's inner life; it concerns its sensations."

What, exactly, do you think sensations are if not part of the inner mental life of whatever is having the sensations?

My point was not that I know anything about octopuses, so my state of ignorance is entirely irrelevant. What I do know, however, is that it is impossible for anyone to know what an octopus (or any other living being except themself) is feeling. That is the sole basis for my statement.

Incidentally, the experiment with blindfolding an octopus demonstrates solely how an octopus may act when its sense of sight is temporarily removed. There is no way to know the underlying reason that it acts that way -- perhaps, for example, it is panicking. Or perhaps in total darkness it has an instinct to withdraw and stop moving -- there are any number of possibilities.

Now let me address what K-22-22 wrote: "The octopus or other cephalopod (indisputably) doesn't have bones and to calculate where their limbs are at any one time requires the processing of more information than their brain can handle."

This is a theoretical argument that is based on a number of unproved assumptions, one of them being that the octopus requires complete, rather than partial, position information about its body. And whatever the octopus feels, it is somehow quite able to deftly move its body into the complicated configurations that it requires (such as -- as I mentioned -- as can be seen in that video of one wrapping itself safely around a shark in preparation for devouring the shark). Obviously it can make whatever calculations are necessary for moving its complex, boneless body around -- and very quickly, too. Are you aware that (and I know this, having worked for NASA for five years) aeronautical engineers can prove that, theoretically, a bumblebee cannot possibly fly? This is true, according to state-of-the-art aerodynamics theory. Yet the bumblebee is unaware of its inability to fly, so it flies anyhow.

One last thing -- it is sad to see people automatically believing one renowned scientific expert, since if you are even slightly familiar with the world of science and especially biology and medicine, you know that renowned experts disagree about important things all the time. So the opinion of one of them does NOT necessarily mean that it is true. And especially if there is no way that anyone can possibly know what is being claimed -- as is the case here.Daqu (talk) 02:54, 29 March 2009 (UTC)

P.S. Here is a verbatim quotation from a 1960 paper, freely available on the Internet, by the very same M.J. Wells:

"[P]roprioceptive information must enter the central nervous system—it is difficult to see how the animal could coordinate movements of the eight arms without it—but is evidently not available for integration with other sensory information in learned processes."

So Dr. Wells is *not* saying that octopuses have "poor" proprioceptive sense, as is claimed in this article (and apparently copied many dozens of times all over the Net, as Wikipedia articles tend to be). He is in fact affirming that they must have a reasonable proprioceptive sense if they are to coordinate their 8 arms -- something I also mentioned (that doesn't require any extensive learning about octopuses, by the way).

Rather, Wells is saying that octopuses cannot easily integrate their proprioceptive sense with other sensory information. (And specifically, with other sensory information in learned processes in laboratory tests.) That is quite a different thing from saying they have poor proprioceptive sense.Daqu (talk) 03:24, 29 March 2009 (UTC)

This discussion is not productive. Come back when you have a citation. —Dominus (talk) 04:29, 29 March 2009 (UTC)

And as for you, Dominus, please come back when you comprehend that having a discussion is not simply putting down someone else, but actually responding to their points, a concept that currently appears to be beyond you.Daqu (talk) 17:32, 29 March 2009 (UTC)

Okay, you Einsteins, here is a citation. From "Proprioception and visual discrimination of Octopus", Journal of Experimental Biology, vol. 37, issue 3 (September 1960), freely downloadable at

< http://jeb.biologists.org/content/vol37/issue3/ >:

". . . would appear to confirm the over-all impression that proprioceptive information is not available for learning, although it clearly must contribute to many essentially reflex activities in movement and in the maintenance of posture"

Here's another citation, from Encyclopædia Britannica, latest online version (retrieved March 30, 2009), in the article mechanoreception:

"'Among other invertebrates, the cephalopod Octopus clearly exhibits proprioceptive abilities, though specific receptors have not yet been identified. These animals, however, seem unable to integrate proprioceptive data in the central nervous system with other sensory information in learning."Daqu (talk) 18:57, 30 March 2009 (UTC)

I will add that there are currently 675 Google hits for the erroneous sentence "However, the octopus has a very poor proprioceptive sense" that was evidently copied verbatim from this Wikipedia article. (Of these, 672 also contain the next sentence of the Wikipedia article as well.) The Internet is a hall of mirrors, but especially for Wikipedia -- misinformation gets vastly magnified. So we have a very high responsibility to get things right as soon as possible.Daqu (talk) 19:06, 30 March 2009 (UTC)

Great, thanks. That all seems to me to be quite consistent with the article's claim that the octopus's proprioceptive senses are limited, and probably unavailable to its brain. What specific change to you think should be made to the article to incorporate this elaboration? —Dominus (talk) 19:24, 30 March 2009 (UTC)

No, nothing I've quoted is consistent with the statement that the octopus's proprioceptive sense is "very poor" or even poor in any way. Only that it is limited in its ability to be integrated with other information in octopus learning. This is something entirely different. Of course the proprioceptive data is available to its brain, or one would see the octopus's arms bumping into each other, which one doesn't see.

I would like to see exactly what M.J. Wells said that led someone to interpret it as a claim that the octopus's proprioceptive sense is "very poor". (Haven't yet got my hands on that book, but I ought to have it within a few days.)Daqu (talk) 19:42, 30 March 2009 (UTC)

I think your claim that "proprioceptive data is available to its brain, or one would see the octopus's arms bumping into each other" is based on a mistaken notion of octopus neurology. It is like claiming that "of course a bull can see in color, or else it would not charge the matador's red cape". In discussing this point of yours earlier I pointed out that the octopus brain can gain awareness of its body position visually, and that experiments with blinded octopuses show that this is indeed how it obtains this information; you did not address this, except to make a casuistical argument dismissing it as being inconclusive, and providing no reliable alternative yourself. Your comments on this matter demonstrated that you don't have the slightest idea what the content of the experiments actually was.

You have again implicitly assumed that proprioception is the only way that the octopus could coordinate its limbs. But this is an unwarranted assumption, particularly since your knowledge of cephalopod anatomy and neurology is nil. As the Britannica article discusses, the proprioceptive information is available to the distal nerves for reflex actions, which in the octopus are much more complex and highly-coordinated than in vertebrates, and so there is no need for proprioceptive information to be available to the brain in order for the octopus to keep its arms from bumping into each other. So evidence from both behavioral experiments and neuroanatomical analysis agree that the octopus brain does not have access to proprioceptive information. Nothing in the Britannica article or the Wells paper is at odds with this, but you've overlooked the possibility in your rush to assume that the octopus sensorium is just like a vertebrate's. —Dominus (talk) 09:27, 1 April 2009 (UTC)

At risk of beating a dead horse, I would like to quote the M.W. Wells paper you cited above, "Proprioception and visual discrimination of orientation in Octopus", regarding the integration of proprioceptive information with the central nervous system of the octopus. On page 497, Wells says "This implies that postural information from pressure and stretch receptors…is not integrated centrally with the retinal input in the determination of orientation of figures seen." That is, the octopus's brain cannot make use of proprioceptive information in making high-level decisions, such as whether to attack. Page 498 has a more extensive discussion of this point, citing a number of earlier papers on the subject: "(Octopuses) cannot be trained to make discriminations that depend on…the relative positions of receptors on the arms." "Attempts to reach octopuses to discriminate between objects differing in weight have so far failed, which again implies that proprioceptive information…is not available as a basis of learned adjustments in behavior." "Octopuses do not learn to use other proprioceptive information about the position of the arms and body in order to orientate themselves after statocyst removal…(This) would appear to confirm the over-all impression that proprioceptive information is not available for learning…" And so on.

I think there is plenty of room in the article for an expansion of the article to discuss octopus proprioception in more detail, including the function of the statocysts, and so on. But it seems to me more clear that ever that your basic point—that it is "impossible for any research to determine (this)"—is not supported by the literature on the subject. —Dominus (talk) 19:20, 2 April 2009 (UTC)

It is beating a dead horse to repeat what I have repeatedly acknowledged -- Wells's conclusion that proprioceptive information does not appear to be available for learning (at least from laboratory experiments). Which is an entirely different thing from saying that the octopus does not have and use the proprioceptive information, which Wells has clearly acknowledged is what happens.

As far as the octopus's use of vision to determine the position of its arms goes, I don't believe it is capable of usually seeing the position of its arms on the side behind its eyes. I don't think the Encyclopaedia Britannica would claim octopuses have adequate proprioceptive sense -- as also does M.J. Wells -- if they didn't have it. This is evident simply from the octopus's use of all eight arms in complex and rapid motion -- and never do they bump into one another, which would happen often if the octopus didn't know in some central place where they all are, at least on some level of consciousness.

Suppose your organs of vision or organs of balance (which is what statocysts are) were removed. The resulting disorientation would make any attempt to extrapolate, from experimental results about your behavior under those conditions to your normal abilities, seriously suspect.

Quoting from Dominus's recent post: ". . . so there is no need for proprioceptive information to be available to the brain in order for the octopus to keep its arms from bumping into each other". But proprioceptive information is essentially synonymous with avoiding different parts of one's body's bumping into each other. No matter how that information may be gathered.Daqu (talk) 21:25, 2 April 2009 (UTC)

Finally I have the only evidence that the Einsteins who guard this page find acceptable -- the book on "OCTOPUS -- Physiology and Behavior of an Advanced Invertebrate" by none other than M.J. Wells, 1978.

NOWHERE in any of its references to proprioception can I find anything that could be remotely interpreted as saying that octopuses have a "very poor" proprioceptive sense. If anyone believes there is something that Dr. Wells wrote that does say this, let them quote Dr. Wells (or some other accepted expert) verbatim so we can see what the basis for that "very poor" claim is. Or -- please! -- forever hold your peace.75.61.107.235 (talk) 07:24, 5 April 2009 (UTC)Daqu (talk) 19:01, 8 April 2009 (UTC)

Reading over this discussion after an absence of two weeks it strikes me that it is almost entirely unproductive, principally because the information is hazy and none of us appear to have any actual knowledge about octopus neurology, combined with the sad fact and people seem to have taken fixed positions from which they are not willing to consider anything their 'opponents' have to say, partially, I suspect, because the original question was presented in somewhat unscientific terms. Unfortunately Martin Wells recently passed away recently or he could have been consulted on the question. However, I think it is fair to say that octpuses have a generally reduced proprioceptive abilities compared to animals of comparable intelligence, partly becuase they have eight limbs, partly because they have no joints, and partly because their limbs have a degree of autonomy. Although I'm not a blind believer in compromise, I think the article could, however, safetly be elaborated upon, provided of course that the facts are kept to - indeed I will embark on such when I have time in about 2 weeks if this would be helpful. Hope this helps - K-22-22 (talk) 01:26, 11 April 2009 (UTC)

Suggested move

Apart from the Hexapus mention, the content of the See Also section is better suited to the Octopus disambiguation page. —Preceding unsigned comment added by 202.161.13.58 (talk) 03:23, 11 April 2009 (UTC)

Tentacles

(as distinct from the tentacles found in squid and cuttlefish)

I moved the above here, pending citation. I don't think it is useful to direct people to the tentacle article for an explanation as to why octopses have arms instead of tentacles, when there is none there. Octopuses arms fit easily into the definition given at tentacle (flexible, sensitive, for grasping), so both articles need citing, and a greater explanation of what a tentacle is or is not.Yob Mod 10:36, 11 June 2009 (UTC)

Link to Cephalopod arm? William Avery (talk) 10:38, 11 June 2009 (UTC)

The link would be useful anyway (even if to an uncited article), thanks for pointing it out!.

Google scholar finds nearly 7000 scientific articles calling octopus arms "tentacles". I'm not advocating changing the terminology here (so just left it calling them arms), but we equally should not be trying to impose a POV when there is no scientific consensus. Biologist sometimes call them tentacles and sometimes arms to distinguish from other tentacle types - editors have chosen to do the latter here to avoid confusion, but we should not be saying the alternative is wrong, especially with no source.Yob Mod 10:47, 11 June 2009 (UTC)

I just delved into The Science of Life and found a passage where 'arms' is used of an octopus, and 'tentacles' of some other sea creatures. Sourced or not, it seems to be long-standing distinction among zoologists, even if the assertion that an octopus doesn't have tentacles seems ridiculous to the rest of us. William Avery (talk) 11:11, 11 June 2009 (UTC)

Yes, octopus arms certainly fit the definition of tentacles, and they are commonly referred to as such in the popular press (and, as you point out, some scientific articles). However, from my experience, most specialist literature on cephalopods calls them arms. This distinction between arms and tentacles is carried over from squid and cuttlefish (8 arms + 2 tentacles), where the two types of limbs usually differ greatly in morphology. mgiganteus1 (talk) 11:34, 11 June 2009 (UTC)

It's also important to note that modern octopuses evolved from ancestral forms which possessed a full complement of 10 limbs. The vampire squid (8 arms) is an interesting case, as it still bears remnants of these two extra limbs in the form of small filaments. mgiganteus1 (talk) 11:50, 11 June 2009 (UTC)

I thought that the squid experts refer to the two longer suckered appendages as "tentacles", and the eight shorter ones that are homologous to octopus arms as "arms". If this is general terminology among scientists, then referring to octopus appendages as "arms" and not "tentacles" makes sense. —Dominus (talk) 14:02, 11 June 2009 (UTC) (Addendum: Cephalopod arm confirms my understanding. —Dominus (talk) 14:02, 11 June 2009 (UTC))

And yet some octopus experts publish articles in peer reviewed journals calling them tentacles. There is clearly not a homogenous consensus on this, so we should not be misinforming readers by pretending there is. It still needs citing, and attributing.Yob Mod 09:00, 29 June 2009 (UTC)

anatomy?

The body plan of the octopus, squid, and cuttlefish is very different from ours. I would like to see something in the article about the anatomy of an octopus. Maybe a diagram showing the location of the major organs would help. SlowJog (talk) 12:45, 30 June 2009 (UTC)

Yes, I agree I think there should be at least a diagram of an octopus's anatomy here. PUT ONE! Cause I don't have one. thanks. --InvaderCito (talk) 00:06, 11 October 2009 (UTC)

useful

I learnt a lot from reading this article. It's fantastic! Great work everyone. For example, the Physiology section has a great attention to detail despite its brief nature. —The preceding unsigned comment was added by 220.253.9.41 (talk • contribs).

The comment on octopuses playing with toys is not entirely consistent with the referenced source. The article says that the octopuses used their water jets to cause the "toys" to circulate in the water, but it does not say that they ever "caught" the toys with their tentacles. In fact, the article questions why the octopuses used their water jets instead of their tentacles, and refers to the fact that the tentacles may be semiautonomous from the brain. —Preceding unsigned comment added by 38.101.195.70 (talk) 23:29, 15 December 2009 (UTC)

Octopus'

I just corrected the grammar, the genitive of octopus is octopus', not octopus's, but this was immediately changed back. This was not vandalism! -- spaceLem (talk) 11:26, 25 December 2008 (UTC)

Are not both forms valid? Dbfirs 09:08, 4 March 2009 (UTC)

Actually no, they're not, a word ending in an s, when it takes an apostrophe (as in the genitive in this instance), no secondary s is added. Thus, you will see Smith's and Jones', even though the second example is pronounced as "joan-zez." —ᚹᚩᛞᛖᚾᚻᛖᛚᛗ (ᚷᛖᛋᛈᚱᛖᚳ) 03:33, 21 May 2009 (UTC)

The "any word ending with s" is a common error. Only plurals loose the post apostrophe s. Refer to Lynne Truss, OED Octopus's Garden [[6]] and many others. MrMarmite (talk) 09:37, 8 July 2009 (UTC)

Don't you mean "only plurals LOSE the post..." not "only plurals LOOSE the post..." LOL —Preceding unsigned comment added by 68.43.233.110 (talk) 10:44, 30 November 2009 (UTC)

According to The Chicago Manual of Style, §7.17:

The possessive of most singular nouns is formed by adding an apostrophe and an s…. This practice, used in conjunction with the exceptions and options outlined in §7.19–22, reflects the way possessive forms are generally pronounced…".

"Octopus" does not fall under the exceptions in §7.19–22. However, §7.23 offers "an alternative practice":

Those uncomfortable with the rules, exceptions, and options outlined above may prefer the system, formerly more common, of simply omitting the possessive s on all words ending in s—hence “Dylan Thomas’ poetry,” “Maria Callas’ singing,” and “that business’ main concern.” Though easy to apply, that usage disregards pronunciation and thus seems unnatural to many.

I think it's not worth arguing about, and that we should make the page's usage consistent, one way or the other, and then leave it that way.

—Dominus (talk) 13:57, 8 July 2009 (UTC)

Interesting. My point was that there are many references to Octopus's, and it is pronounced with the extra s...it's not sung as "In an octopus garden. MrMarmite (talk) 16:06, 8 July 2009 (UTC)

Am i allowed to talk without being banned here? —Preceding unsigned comment added by 69.180.238.191 (talk) 23:08, 2 October 2009 (UTC)

Range of Octopus

There needs to be a section discussing the range/ranges of the octopus.167.7.33.2 (talk) 16:37, 5 January 2010 (UTC)

Where is the beak?

Where is the octopus' beak located? The article makes no note of this. – 129.241.137.240 (talk) 01:11, 2 December 2009 (UTC)

Well the reason is simply that nobody has posted a topic about the location of the octopuses beak. I think it is below the eyes... obviously it could be knowhere else. —Preceding unsigned comment added by 70.177.230.133 (talk) 22:11, 4 March 2010 (UTC) Octopi beaks are in the middle of the underpart of the body where the tentacles meet.

Octopuses?

The correct plural of Octopus, is "octopodes." Lion King 03:21, 12 February 2006 (UTC)

No, it isn't. See the discussion above. - UtherSRG (talk) 02:19, 13 February 2006 (UTC)

Whilst it is often supposed that octopi is the correct plural of octopus and has been in use longer than the Anglicized octopuses, it in fact originates as an error. Octopus is not a simple latin word of the second declension, but a latinized form of the Greek word oktopous and it's correct plural, would logically, be, octopodes. Lion King 02:37, 13 February 2006 (UTC)

But the funny thing about the Greek word πούς (pous) is that while it is indeed a third-declension word with a stem ποδ- (pod-), it is irregular in that it also has an alternative second-declension stem πο- (po-), seen in the second-declension Doric form πός (pos) as well as in certain inflections of the compounds of πούς such as δίπουν (dipoun), the second-declension, neuter, nominative singular form of δίπους (dipous), and even πολύπους/πουλύπους (polypous/poulypous) is declined as a second-declension word as well as a third-declension one. This second-declension variant of the stem gave Latin and English the word polypus, (nominative) plural polypi. That information seems to give an element of legitimacy to the octopi plural form, or at least it seems to make things so that it's no longer a simple matter of using the phrase "mistaken assumption" to refer to the use of the Latinized word octopus as a Latin second-declension word. The way I see it, what's sauce for the goose is sauce for the gander, and what's a possible inflection for the polypus is a possible inflection for the octopus. - Diaphanus 156.34.216.233 (talk) 11:31, 20 July 2008 (UTC) if you have never seen an octopus, then you are a stupid retard

The OED has citations for "octopuses" back to 1884. It has no citations for "octopodes", which it describes as "rare". If you have any actual evidence (as opposed to etymologicval wishful thinking) that the "correct" English plural is "octopodes", please let us know what it is. -- Dominus 03:16, 13 February 2006 (UTC)

No, it's not etymologicval wishful thinking, it's in my copy of the OED, just checked it. If it has no citations for octopodes, how can it then desribe it as rare? it would be more than rare, it would be non exsistent. Lion King 03:53, 13 February 2006 (UTC)

What do you mean, "if"? Did you check it, or not? Did it list "octopuses", or not? If it did, what's your evidence for asserting that "the correct plural is 'octopodes'"? -- Dominus 04:06, 13 February 2006 (UTC)

May I suggest that you go to askoxford.com. It mirrors what I and my OED says. Lion King 04:26, 13 February 2006 (UTC)
USAGE The standard plural in English of octopus is octopuses. However, since the word comes from Greek, the Greek plural form octopodes is still occasionally used. The plural form octopi, formed according to rules for Latin plurals, is incorrect. from askoxford.com - UtherSRG (talk) 04:54, 13 February 2006 (UTC)

I know octopi is incorrect, I have already stated that! Goodbye, Good luck and may your "ocopusies" go with you! Lion King 15:10, 13 February 2006 (UTC)

What are the 'correct' English plurals for nautilus, metalloid, telephone, microscope, dinosaur, etc...? Femto 13:25, 14 February 2006 (UTC)

Oi,gevald! A Sof, A Sof! Lion King 17:55, 14 February 2006 (UTC)

Does anyone else have trouble with the use of the singular 'octopus' as plural in a few of the photo captions? Specifically: 'Octopus at Tsukiji fish market', 'Grilled octopus in Greece', 'octopus are "tickled"' and 'A fisherman's catch of octopus' 1bj05hua (talk) 23:57, 9 November 2008 (UTC)

I corrected "octopus are tickled" to "octopuses are tickled". But I think "octopus at Tsukiji fish market" is acceptable, because there "octopus" refers not to the individual animals but to the foodstuff en masse. This is a common construction in English: consider the analogous cases "steak on sale", "cheese on sale", "pineapple on sale". In each case, the singular form refers not to individual steaks, cheeses, or pineapples, but rather to the material of which these things are made: steaks are made of steak, cheeses of cheese, pineapples of pineapple. Similarly, octopuses are made of octopus. If one put octopus meat into cans, it would be canned octopus, not canned octopuses, just as one has canned pineapple, not canned pineapples. The use of the singular in "octopus on sale at Tsukiji" is analogous. I hope this made sense. —Dominus (talk) 09:46, 28 March 2009 (UTC)

Canned peas? Canned beans? Canned tomatoes? :P --Pyritie (talk) 19:05, 10 June 2010 (UTC)

Although this issue was discussed before, I wish to insist that octopi is not an acceptable plural. The article committed a famous schoolboy howler by offering it as an alternative plural. It would be, if the word was latin in origin. However, its origin is classical Greek, as is Cephalopod. The 'feet' ending coumes from 'pous' (I'll use our letters for simplicity). The plural of pous is podes, usually written 'pods' in English. So cephalopods is fine, whereas octopi is simply wrong. Don't feel bad about it; remember that in Goldfinger Ian Fleming has Pussy Galore saying "My father was an expert on octopi", thus proving that he wasn't, or he would have taught her the right word!

The plural of Octopus is Octopods, or Octopodes if you must. Dictionaries also offer the rather inelegant Octopuses. The article also uses Octopus as a plural: although that is an invention, it is absolutely preferable to an outright error. Macdonald-ross (talk) 09:09, 28 March 2009 (UTC)

English dictionaries invariably support the use of "octopi" as a plural. For example, ^[1]^[2]. It's not the job of wikipedia editors to try to legislate linguistic norms, even those based in etymology. Rather, Wikipedia articles should report on what can be supported by reliable, authoritative sources. If you have a source for your claim that "octopods" is a plural of "octopus", please cite it. My own understanding is that "octopods" is the plural of "octopod".^[1]^[3]^[4] Accordingly, I am reverting your changes. —Dominus (talk) 09:31, 28 March 2009 (UTC)

^ ^a ^b William Morris (ed.). "octopus". American Heritage Dictionary of the English Language.
^ "octopus". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
^ William Morris (ed.). "octopod". American Heritage Dictionary of the English Language.
^ "octopod". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)

Greek nothing, speak English or get out. —Preceding unsigned comment added by Wōdenhelm (talk • contribs) 22:46, 23 May 2009 (UTC)

The OED has never actually said that one form or another is incorrect, since the OED isn't a prescriptive dictionary. It merely states that the word "octopi" is one of the plural forms, because that's how the OED scholars have seen it used. Octopodes is another form listed. Since people continue to use all of them, they will continue to all be listed in the dictionary. The fight over what is the correct form is therefore silly.. Anyway, since this article incorrectly implied that the OED used the word "mistaken" I have corrected the entry and updated the OED retrieval date. (Or tried to anyway.) The OED never used the word, "mistaken." It only accurately traces the logic of the people who use the octopi form. Even when the OED makes an implication about which form is correct (as in the concise askoxford entry) it still only says that the *reasoning* people use for the octopi form is incorrect, not that the use is. Therefore, the continued use of the "octopi" form could in fact be justified simply by continuing to use it! Kothog (talk) 20:29, 1 February 2010 (UTC)

evolution?

Can someone provide information about when the octopuses evolved? Maybe even when they differentiated from the vampire squids? Other taxonomic articles have keen diagrams showing the taxon's fossil range, but there's nothing like that for Octopoda. 71.227.187.128 (talk) 17:17, 30 December 2008 (UTC)

Agree - this is evolutionary tree and fossil record is an important information for a page like this. Fig (talk) 19:47, 14 December 2009 (UTC)

The book "Evolution" (2009, Octopus Publishing Group Ltd., p.134-135) states that the common octopus evolved not later than the middle Jurassic. Fossils of o. vulgaris have been found on the sea bed of La_Voulte-sur-Rhone, dating back 163 million years. —Preceding unsigned comment added by 85.179.94.28 (talk) 19:33, 8 June 2010 (UTC)

anatomy and development?

when does the octopus have blue eyes? what stage of development? when was this first noticed, written or published reference would be very helpful. Beyond cold and hot water adaptation? Item of interest was the surgical procedures reported in India of multilimbed children. Any noted items on experimentation in laboratories? To my knowledge the reference in literature have always indicated black eyes. —Preceding unsigned comment added by 97.116.68.67 (talk) 16:53, 7 February 2010 (UTC)

A question about intelligence and life span

Hi! If anyone knows, I for one would appreciate a solution to a conundrum. The brain is an expensive organ to grow and maintain, and learning takes time. Octopodes (if we follow the above) are short-lived. Is there a reasonable explanation for why they invest so much of their limited time in this? All the best 85.220.111.211 (talk) 19:36, 9 January 2010 (UTC)

They are short-lived relative to, for example humans, but live several years, long enough perhaps to benefit from experience.

Another related question: The article discusses that they learn almost nothing from their parents, implying that they may learn something. How can this be known at all, one way or the other?--Jrm2007 (talk) 08:16, 20 June 2010 (UTC)

Slit pupil causes astigmatism

"Although their slit-shaped pupils might be expected to afflict them with astigmatism, it appears that this is not a problem in the light levels in which an octopus typically hunts". This statement is incorrect. The lens, which changes the vergence of light behind the pupil is spherical, not cylindrical. Fillup (talk) 22:16, 18 January 2010 (UTC)

The octopus does not travel head first

It has no 'head' to speak of. When it jets, it travels mantle-first, which is similar to saying it travels ass-first. 70.179.127.14 (talk) 23:54, 19 April 2010 (UTC)

The octopus has a head, which contains its brain. The mouth and the eyes are on the head. Hope this helps. —Mark Dominus (talk) 01:46, 20 April 2010 (UTC)

Predictive abilities

So, where could we include the incredible powers of octopus prediction, especially that of the one which predicted many Soccer World Cup games with 100% accuracy? —Preceding unsigned comment added by 222.155.76.157 (talk) 23:24, 11 July 2010 (UTC)

Diet

What do octopuses eat? Are they considered predators, scavengers, or something else? How do they obtain their food? The article should address these points. Ishboyfay (talk) 15:39, 17 July 2009 (UTC)

Agree. --Westwind273 (talk) 04:53, 8 July 2010 (UTC)

http://www.enchantedlearning.com/subjects/invertebrates/octopus/Octopuscoloring.shtml According to Enchanted Learning, it eats crabs, scallops, fish, turtles, other octopuses, and crustaceans. It grabs it with its arms, chomps it with it's beak (apparently venomous) and sucks out the flesh. Lovely! --69.151.229.115 (talk) 01:14, 8 October 2010 (UTC)

Plural of octopus

{{editsemiprotected}} the plural of octopus is octopodes, not octopusses as written in this article, as explained here http://www.askoxford.com/asktheexperts/faq/aboutgrammar/plurals?view=uk —Preceding unsigned comment added by 81.139.101.24 (talk • contribs) 09:13, 21 December 2009, Monday (UTC-5)

See Octopus#Terminology and the sources listed therein. ~ Amory (u • t • c) 14:30, 21 December 2009 (UTC)

It's already been covered to death, hasn't it? I tried to follow the link to askoxford but couldn't find that page. However, when I type "octopus" into that site, the dictionary entry shows only one plural (octopuses), and adds a usage note: "The standard plural in English of octopus is octopuses. However , the word octopus comes from Greek, and the Greek plural form octopodes is still occasionally used . The plural form octopi is mistakenly formed according to rules for Latin plurals, and is therefore incorrect." So that seems pretty clear. It has long been held that once a word is fully absorbed into English, English plurals should be used. Also, the main article lists Chambers 21st Century Dictionary, but the main Chambers Dictionary goes further by including a note that says "octopi is wrong".

This also contradicts an earlier comment in the discussion that English dictionaries "invariably" support the use of "octopi". Obviously, at least one respectable dictionary does not! The writer of that comment also stated it is not up to wikipedia to "legislate" linguistic norms. Maybe. But no-one is talking about legislating anything here: you can say what you like in your own works. Here, we are only talking about wikipedia "using" (rather than "legislating") the form that most English authorities appear to recommend. AlistairLW (talk) 19:11, 29 September 2010 (UTC)

Octopus cooking

[[File:Casa Ezequiel.jpg|thumb|250px|Galician people|[[Galician people|Galician]] woman preparing ''[[polbo á feira]]'']]
[[File:Polbeira, A Coruña, Galiza.jpg|thumb|250px|Galician people|[[Galician people|Galician]] woman preparing ''[[polbo á feira]]'']]

Would anyone add any of these pictures? I think they are rather interesting for the article. The images depict two women preparing polbo á feira.--194.80.194.85 (talk) 20:36, 11 May 2010 (UTC)

They're too specific, and there are enough food pictures already. I pre-tagged them to prevent them from overflowing into the rest of the talk page. ~rezecib ^(talk) 22:05, 20 November 2010 (UTC)

Sense of smell?

The sensation section does mention that octopuses have chemoreceptors on their arms, but it equates this sense more closely to "taste" than smell. Is anyone aware of whether octopuses have an independent sense of smell? That is, the ability to detect molecules at low concentrations in the surrounding water, in the manner that sharks are said to detect blood? NillaGoon (talk) 20:35, 8 November 2010 (UTC)

Although I don't know about it myself, the distinction between "smell" and "taste" seems a bit blurry to me in an aquatic context, so I'm not really convinced it matters which word is used. It would be interesting if someone found a source that addressed this, though. ~rezecib ^(talk) 21:08, 8 November 2010 (UTC)

Underwater, there is no distinction between smell and taste, except, perhaps, that one is in the mouth. Anything an octopus could sense with its chemoreceptors would be a soluble molecule in the water around the chemoreceptors. I'll try to get some sources, although there isn't a lot of direct evidence that octopuses have chemoreceptors on their arms (just behavioral and morphological evidence.) I remember reading about chemoreceptors on their lips once - I'll try to check that out in the near future. Lisieski (talk) 21:05, 20 November 2010 (UTC)

Diet

What I miss is a piece about what Octopedes usually eat. I guess small fish right? —Preceding unsigned comment added by 38.112.242.106 (talk) 15:27, 9 July 2010 (UTC) There definately should be a section about diet. octopi eat crab and shellfish so someone should implement greater knowledge then mine to write up a section about this. — Preceding unsigned comment added by Sjhammerton (talk • contribs) 20:53, 11 December 2010 (UTC)

Octopi

Octopi is correct! Anything ending with -us to make plural you put i at the end! Maybe if you werent all doofi you would know that! P.S. I already changed the article to say octopi! Inurfaces! —The preceding unsigned comment was added by 136.142.20.226 (talk • contribs).

Well, virus doesn't have a Latin plural, so what then? 85.220.111.211 (talk) 20:55, 9 January 2010 (UTC)

And what about the plural of ignoramus? 85.220.111.211 (talk) 21:00, 9 January 2010 (UTC)

f### all of you! its octopi —The preceding unsigned comment was added by 136.142.20.226 (talk • contribs).

What are you? A sex maniac? then go back to bed and do it with your spouse! or your special "friend" By Mr. Mystery —The preceding unsigned comment was added by 136.142.20.226 (talk • contribs).

Sorry, Wikipedia is WP:NPOV and descriptive, not POV and prescriptive. --Kjoonlee 14:51, 3 December 2006 (UTC)

- Actually, you're wrong, anonymous. Octopus doesn't end in -us, it ends in -pus, meaning foot. So while Cacti is correct, Octopi IS NOT, although generally accepted. :) Almighty Rajah (talk) 19:17, 27 July 2008 (UTC)

About as accepted as "octopussies"? Dbfirs 08:59, 4 March 2009 (UTC)

Well, The Shorter Oxford English Dictionary gives the forms octopuses, octopi and octopodes in that order but without marking any particular form as rare. We can probably assume all three are correct. But since this is such a perfect battlefield for Latinists, Grecians (yes, the same word GWB was mocked for and Keats was not above using) and then of course the plain vulgus, let's have some more. ;-) 85.220.111.211 (talk) 19:55, 9 January 2010 (UTC)

By the way, couldn't resist, so the plural of bus is bi? Cheers 85.220.111.211 (talk) 21:42, 9 January 2010 (UTC)

Actually, it does say (rare) for one of the forms. Specifically, it says, "Plural octopuses, octopi, (rare) octopodes". OED Reference Anyway, this is another half of the same discussion near the top.. Kothog (talk) 20:34, 1 February 2010 (UTC)

OCTOPI IS CORRECT!!!!!!!!! — Preceding unsigned comment added by Sjhammerton (talk • contribs) 20:55, 11 December 2010 (UTC)

What's actually pretty amazing about this discussion is all the people who are completely ignorant of the grammatical structure of Latin and Ancient Greek, and YET who are 100% absolutely totally positive that any "old-timey word" that ends with -us has its plural in -i. Thank you, Rajah, for standing strong. "Octopi" is a Latin word created by English-speaking Americans who have no knowledge whatsoever of Latin. Mardiste (talk) 22:10, 31 December 2010 (UTC)

And if S.J. Hammerton wants to convince me otherwise with respect to his knowledge of Classical languages, then he's going to need more than eight exclamation points. By the way, does anyone else have the sneaking suspicion that, instead of using the caps lock button, S.J. Harrington was "correcting" people's Latin declension by holding down the shift key while typing his entire ill-informed message with his right index finger? Mardiste (talk) 22:18, 31 December 2010 (UTC)

Octopus farming

I have read a couple of articles on the internet about farming octopuses. Is this common? Or are they generally hunted/captured from the wild? Given that they appear to be able to fit through extremely small gaps, octopus farms must be quite specific. Does anyone have any information on this?

Taxobox Titles Need Fixing

The background for the headings are blue, as is the text so it's unreadable, I don't know how to change it though, maybe some master wikipedian can help out here :P

Swimming

In the locomotion section, it states that octopi swim by jetting water out the siphon. I know that this is true, but I think I have witnessed another method. I have just viewed a video that shows an octopus doing what looks very similar to swimming like a fish. Maybe it's using its jet, but it does look like it is moving by undulating, using its trailing tentacles in a similar fashion to a fish tail. This form of locomotion is horizontal, not verticle like a fish. Also, the octopus in the video is not moving head first like the article says. The video is located here: [7]. The suspect portions start at 3:12 and another at 4:12. 75.88.30.191 (talk) 06:09, 3 December 2009 (UTC)

That's jetting. The octopus is pointing its siphon the opposite direction of the way it swims, and rapidly expelling water from it. The arms trailing behind it are not contributing to its movement at all. Lisieski (talk) 18:38, 23 November 2010 (UTC)

Cephalopod Crypsis pp 5-6 shows it chooses to swim like a flat-fish or jellyfish ! --195.137.93.171 (talk) 19:07, 7 January 2011 (UTC)

Colourblind ?

Given the octopus' amazing ability to camouflage itself, I was surprised to see it described as "almost certainly" colour-blind. Octopii beat the chameleon at its own game - they change shape and even texture, not just colour. [8] LOL - that search finds several informal sources that say it's colour-blind ! Maybe we can find a better citation ? [9] Some think it detects colour by touch ! Perhaps with surface receptors like the Nautilus, but using a contact print not pinhole camera ? Cephalopod Crypsis says it matches a photograph or through glass, but with less 'depth' than on a 3D surface !

[10] [11]

[12] "However, spectral discrimination could be provided by involving other skin structures (chromatophores and iridophores), which produce changeable colours and patterns." So it seems to 'see' with its whole skin, and may detect colours 'holographically', rather than using pigments. Makes me feel pretty inadequate.

Given that they can even produce polarization patterns that are almost invisible to us, I suspect that they can see colour, even though they do not use colour sense mechanisms that we recognise and understand, and do not always co-operate in experiments. However, I leave it to the experts !

[13] colour matching looks pretty good to me, especially given the variation in colour vision among individual humans, let alone predator species.

--195.137.93.171 (talk) 18:29, 7 January 2011 (UTC)

De-archiving dead discussion threads

Dominus (talk · contribs) has just de-archived 9 stale discussion threads. As one example, Dominus de-archived a section that had one comment only, created by an IP who has not edited since January 5, 2010. Another section similarly had only one comment by an IP who edited only on Feb 7 and 8, and has not edited since. These and the other archived sections are clearly dead. Dominus, can you explain why you de-archived them? Jayjg ^(talk) 02:20, 3 January 2011 (UTC)

This page is often visited by unregistered users and by users unfamiliar with Wikipedia, and a long expire time will serve those users better. The slow archiving time will support that, and in my opinion, will not cause a problem for the regular users of the page. Discussion here is often slow, and volume is not so great that a more aggressive archiving policy is needed. When another editor, one who has never contributed to the Octopus article itself or to the talk page, unilaterally changed the archiving policy that I had set up after consulting with the group, I acted to restore the status quo.

Your use of the phrases "stale" and "clearly dead" is question-begging. I believe that there was no problem here that required your intervention, and cordially invite you to go do something constructive that will improve our encyclopedia. —Mark Dominus (talk) 14:55, 3 January 2011 (UTC)

The only question being begged here is how a "long expire time will serve" unregistered users in any way. These conversations are dead, because the person who asked the question has never come back and never will, and no-one else cares about the questions, or they would have responded at some point in the past year. Having them around wastes everyone's time. Archives exist for a good reason, and making them work properly is "something constructive that will improve our encyclopedia". Jayjg ^(talk) 22:36, 3 January 2011 (UTC)

Have it your way. —Mark Dominus (talk) 00:56, 5 January 2011 (UTC)

- I frequently come back well over a year after a discussion. science works that way. Also if there is an edit war I am put off contributing. If there are lots of comments of course archive quickly. IF not leave them around until the article incorporates the info somehow. If there is a question asked WHY should it be automatically answered within a month or even a year? Most PhD courses are 3yrs minimum, so why not leave items for 3 yrs minimum? Then if a researcher does look here and find the answer in their research they have enough time to investigate, peer review and publish. — Preceding unsigned comment added by 88.113.96.60 (talk) 08:32, 4 June 2011 (UTC)

Sports

A brief summary of the strong role the octopus plays in sports, as referenced in the see also section, should be discussed in the same manner as literature. It should include both Paul the Octopus as well as the tradition of Octopus throwing at Red Wings playoff games. Any other submissions, of course, can be added as needed. Lacking this section gives an incomplete picture of the Octopus' role in culture. Thoughts?≈ —Preceding unsigned comment added by 108.16.7.204 (talk) 16:36, 9 February 2011 (UTC)

Octopus as metaphor

I think there is little question that the octopus as political metaphor is interesting, long-standing, and well-supported by evidence. Vulgar Army is a blog devoted to examination of this metaphor, and contains dozens of examples of octopus-related propaganda from the last hundred and fifty years. The example at right was published in 1913. I'm not sure this article is the right place for it; maybe a very brief section with a pointer to a standalone article would be more appropriate. —Mark Dominus (talk) 14:15, 20 February 2011 (UTC)

Here's one I just happened across on Commons that someone uploaded a few months ago. It is from 1877. —Mark Dominus (talk) 16:46, 13 April 2011 (UTC)

Sentence Fix

The sentence: "Unlike vertebrates, the complex motor skills of octopuses are not organized in their brain using an internal somatotopic map of its body, as is the motor system in vertebrates" has a redundancy and lacks a period. I'd fix it myself, but the page is protected. 67.142.165.30 (talk) 22:51, 17 September 2011 (UTC)

Done that, think it's sorted now. Finbob83 (talk) 13:23, 4 December 2011 (UTC)

Tentacles

"Due to having numerous tentacles that emanate from a common center, (...)"
As established in the rest of the article, octopuses do not have tentacles, but arms. Someone with the rights please edit. --83.101.83.57 (talk) 12:18, 17 August 2011 (UTC)

Fixed. Thanks for pointing it out. mgiganteus1 (talk) 13:14, 17 August 2011 (UTC)

Tentacles vs Arms vs Legs: Please take my talk-edit comment at face value because I don't have time to find the research right now. I have seen information (much more recent than referenced) explaining how octopuses have arms AND legs, AND in a common proportion across species. I will try to come back with the references, but if someone else knows better, could you please add the info? (And if that arm-v-leg knowledge has changed, could that be noted too?) Smittee (talk) 07:28, 3 May 2012 (UTC)

I found a ref related to this. It appears that one study came to the conclusion that the two rearmost appendeges are actually legs. It's not clear from the ref I found that this finding has been accepted by the wider scientific community, but I have noted the findings in the "locomotion" section. Beeblebrox (talk) 03:23, 5 May 2012 (UTC)

Octopus' brains

This video is under a creative commons license and has good cut-away images of the color-texture changing mechanisms of their skin-cells, as well as anatomical information concerning their brain neurons in their capacity of being convergent yet separate in brain evolution for behavioral plasticity to humans. Anyone wanting to go to work including anything from this video to this article has their work (rewardingly) cut out for them. Nagelfar (talk) 09:49, 14 October 2011 (UTC)

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Edit request on 6 September 2012 update a link

This edit request has been answered. Set the |answered= or |ans= parameter to no to reactivate your request.

Please change the link at Conference on Cephalopods and Art, Institute for Advanced Study, University of Minnesota, March, 2011 (the last of the external links)

to http://ias.umn.edu/2011/03/25/cephalopod-symposium/

because we changed our website. The old links are not yet finding the new pages. for more information, please contact me, Sharon Fischlowitz, at fisc0199@umn.edu thank you 98.240.214.120 (talk) 05:15, 6 September 2012 (UTC)

Done RudolfRed (talk) 05:32, 6 September 2012 (UTC)

Plural of Octopus

I thought, instead of "octopuses" it was in fact, "octopi" — Preceding unsigned comment added by 75.139.100.19 (talk) 13:38, 6 July 2012 (UTC)

The section on etymology and pluralization is great. I just wonder, though, why it is a 3rd declension noun in Latin. Is that the standard protocol for Scientific Latin? --Richardson mcphillips (talk) 03:37, 21 July 2012 (UTC)

The -pus part of the word is a latinized version of Greek πους (pous), "foot". It's not the second declension because the -us in the word is not a suffix but part of a compound word meaning "eight foot". i.e. it's not similar to words like locus, genius, focus, etc. where the -us is simply a a nominative singular suffix and would be dropped for their plural forms loci, genii, and foci. Pluralizing -pus into -pi would be comparable to pluralizing English "walrus" to "walri".

The -pus part has the same origins as the -ped and -pod suffixes in things like podium, tetrapod, arthropod, cephalopod, platypus, tripod, podiatrics, etc.

"Octopus" is also a modern invention, it never existed in classical Latin. There was a similar word in Latin: polypus ("cuttlefish"), which in contrast did indeed use polypi as plural, and is the origin of the modern English word "polyp". But that is the result of Latin speakers not realizing that polypus is actually a compound word. Comparable to how English sometimes applies the -s plural in foreign loanwords where it would be incorrect in the original language, e.g. English "tableaus" instead of "tableaux", "seraphs" instead of "seraphim", and "ninjas" instead of "ninja".-- OBSIDIAN†SOUL 06:23, 21 July 2012 (UTC)

thanks, that's very helpful. Given the example of polypus/polypi, is there any evidence of how the creators of the Latin word octopus intended to pluralize it? I mention polypus/polypi because sometimes things are idiomatic rather than grammatically correct (I don't mean simple errors like modern English speakers creating a word octopi for a wrong reason). --Richardson mcphillips (talk) 04:55, 30 July 2012 (UTC)

Yes, in a way. It originated from a scientific name coined in 1758 by the Swedish naturalist Linnaeus.^{Click here for the gory scientific details} And like all scientific names, we should have used it as is. No grammatical number, no suffixes, no prefixes, nothing. In the same way that the genus Homo, to which modern humans belong to as the species Homo sapiens, should never be pluralized as Homos, hehe.

But language is never a simple thing. During Linnaeus' time, the octopus was known by other naturally derived English words (which was also applied to other cephalopods indiscriminately) which included devilfish, squid, calamary, preak (or preke, preake); pourcuttle (also pourcontrell, pore-cuttle, cuttle, cuttlefish, etc.); and poulp (also polyp, folpo, polpi, poulpe, polpo etc., from French, ultimately from Latin polypus), etc.

See the 19th century results from Google Books and note the transition. In the 1800s it was still referred to by various names like cuttlefish, poulpe, eight-armed cuttlefish, rondelet, eladone, polypus, etc. By the 1830s, "octopus" is being used more and more frequently. Until by the 1870s it was already the primary name being used, and by the 1890s, more or less, the only name. All the rest have been forgotten. Hence the confusion. But as a common name, it's not anymore restricted to the rules of scientific names but to the rules of the language that adopted it. Thus "octopuses" using the regular English plural is quite good enough.

Anyway, as for "octopi"... I guess if we were Ancient Romans who overheard the word from an Ancient Greek fisherman trading in a fishmarket in Magna Graecia in the the 3rd century BC, we'd be justified in using it. But we're not. We'd be artificially recreating a linguistic evolution event that happened by accident during the borrowing of a word in two dead languages. :P That's a bit like copying some text from an old book and then after you've finished jotting down the words, you then proceed to painstakingly recreate the rips and the coffee stains on your fresh copy as well. Hehe

Details galore: the name was originally given to the common octopus in Linnaeus' Systema Naturae. His original name was Sepia octopodia, consisting of the generic name Sepia (from Latin sepia, "cuttlefish") and the specific name octopodia (Scientific Latin from Greek adj. "of the eight feet"), together "eight-footed cuttlefish ".

As the rules of binomial nomenclature were still being formulated back then and the science of taxonomy still in its infancy, the German naturalist Johann Friedrich Gmelin in a later paper in 1791 used Linnaeus' name for the species but changed the Latin to a series of two nouns: Sepia octopus ("cuttlefish eight-footed [thing]").

Sepia, however, was also used as the generic name given for cuttlefish by Linnaeus. Later zoologists realized that cuttlefish and octopuses are only very distantly related and so should not share the same genus (or even the same order, as even later biologists found out). So the French naturalist Georges Cuvier split the octopus off into a new genus in 1797: Octopus. He used the common octopus as the type species and proposed that it be renamed Octopus vulgare to match the new classification and to avoid tautonomy if he retained Gmelin's specific name (i.e. it would have been Octopus octopus).^{Further pedantic note}

And so Octopus vulgare it was. But organizations like the ICZN were later established, and they made new rules to make biology even more consistent. They declared that the grammatical gender of the genus must match the grammatical gender of the specific name. Octopus is masculine, vulgare is neuter. To make them match vulgare was corrected to the masculine form of the adjective: vulgaris. And thus the common octopus finally receives the scientific name we know it by today: Octopus vulgaris, the "common eight-footed [thing]".

Further pedantic note: It so happens that another German naturalist, Johann Gottlob Theaenus Schneider, had actually also renamed it earlier in 1784 as Octopodia polypus. And since Linnaeus was the first to name the species after all, by the principle of priority in taxonomy, his specific name should have been retained. i.e. It should have been Octopus octopodia. But since both were realized too late and Octopus was already too widely used to be replaced again, O. vulgaris was conserved by taxonomical authorities in the 20th century.

I hope that didn't confuse you further. Haha. -- OBSIDIAN†SOUL 12:54, 30 July 2012 (UTC)

The example of polypus/polypi shows that the -pus word element in question is heteroclitic (it can be declined more than one way, not unlike the Latin domus, "home") and not declinable in just one way as the old "Octopi is wrong" argument makes it out as. It has third-declension and second-declension inflections in Latin. The Romans themselves wrote the second-declension forms (Gen.Sg.) Oedipi (for Oedipus), (Acc.Sg.) coronopum (for coronopus), (Gen.Pl.) polyporum (for polypus). That inflection of polypus was used by Plautus, but he knew Greek, so I doubt he didn't realize that the Greek word ends in that -πους. The Greeks themselves (including Homer) wrote forms like (Nom.Sg.) τρίπος (for τρίπους), (Gen.Sg.) Οἰδίπου (for Οἰδίπους), (Gen.Sg.) πουλύπου, (Acc.Sg.) πολύπουν, (Nom.Pl.) πώλυποι, (Acc.Pl.) πολύπους, and (Gen.Pl.) πουλύπων (for πολύπους). At this point, I should quote someone who summed this up nicely:

"Furthermore, it turns out that even in Greek it was sometimes treated as second declension. I mean, if it only happened in latin we could attribute it to dumb Romans making up "pseudo-Greek plurals," but if even the Greeks got it wrong then... well I guess it isn't wrong"

So, while some authorities find that octopi is an objectionable hypercorrection, the real hypercorrection here is insisting that -pus and -πους had only the standard third-declension inflection, when in fact we have various forms like the Greek nominative plural πώλυποι and its corresponding Latin nominative plural polypi.

Octopodes has inflectional precedent from antiquity, but so does octopi. It is true that octopi itself is not attested from then, but neither are the Latinizations octopus, octopodes, and Octopoda. Someone can rightly point out that the ideal inflection is of the third declension, but I could just as easily (and I do whenever the subject comes up) point out that the second-declension inflection is a valid alternative. The fact that the second-declension inflection is not the norm does not make it incorrect.

These are the primary reasons I put no stock in the "Octopi is wrong" argument. -Diaphanus 156.34.228.49 (talk) 07:49, 2 September 2012 (UTC)

Here's the only catch. Octopus isn't Ancient Greek at all. Again you're trying to apply reconstructed lingustic evolution to a word that had never been used colloquially by the Ancient Greeks. πώλυποι is the effect of a compound word slowly losing its compound origins through centuries of colloquial usage. It does not justify an incorrect declension as being acceptable, it merely indicates that the word has been used long enough that its origins have become obscured. Heck, πώλυποι might even be a reborrowed word from Latin. If it were heteroclitic, why isn't the actual word πους itself heteroclitic as well? You don't have πούς pluralized as ποι, do you?

Compare for example, the Modern English word woman. How many modern English-speakers do you reckon still know that the word is actually derived from an Old English compound word wif + man. Or Modern English fortnight and Old English feowertyne + niht? That does not happen happen in Scientific Latin, since the latter is used for the exact reason that it is a dead language.-- OBSIDIAN†SOUL 09:16, 2 September 2012 (UTC)

The Etymology Section of the Octopus page needs correction. Using Wikipedia Latin pages as my reference guide for Latin Nouns. 1st declension nouns feminine singular and plural respectively end in these endings:-A,-AE; Greek assumed 1st declension: -E,-AE; Latin masc -ES,-AE; and Latin masc -AS,-AE. 2nd declension Nouns -masc -US, -I; or masc -R/-ER,-I; or neuter -UM,-A; or Greek feminine -OS/-US, -I; or Greek neuter -UM/-UN,-I 3rd Declension Nouns neuter -O,-ES; or neuter -N,-IS; or neuter +X-, +CT-ES; or neuter I stem +AL,-AI; or Greek assumed masc +,-ES; or Greek IS stem +IS, +ES These Wikipedia case endings agree with Wheelock's Latin book, which is the book used by the University of Washington, Seattle, to teach Latin. The point is this etymological section about Octopus being a third declension Latin Greek assumed ending is messed up, badly. Using your own Latin pages to complete the logic here it goes. If an Octopus or Octopous from Greek with an -OS/-US ending word is assigned a declension in Latin it would be a Second Declension Greek feminine case to Latin transmutation of the word Octopus; according to your own pages on Latin declensions it follows that Octopi is the correct nominative case plural of Octopus. There is no third declension nominative case for a Greek or Latin word ending in -OS/-US, although there are other Greek endings in the third declension Latin for other stems in Greek. It follows that an Octopus in Latin translates to English in the time when scientific notation adopted Latin as the standard for natural description, if not much earlier than Lineaus, and that an Octopus from Greek through Latin to English has not changed as the rules for Latin Declension have not changed in two thousand years. An Octopus is one Octopus, whereas Octopi is the plural. If we are talking of Octopodes as a singular Latin form, that would be a First Declension masculine (Latin form) which makes the plural nominative case Octopodae. If Octopodes is meant as a plural of the word, it would be a third declension neuter making a singular form Octopodo; since, we know we don't use that in our ordinary terminology, I'm fairly certain we can rule that out as an option. Disregard this line as a result. If Octopus were a singular masculine noun in Latin it would still be Octopus/Octopi, and since the Latin and the Greek assumed Latin are the same, I'm pretty sure, we are coming to a logical conclusion that Octopus/Octopi is the longstanding correct version of the word, in English, Latin, and Greek. The information provided on the Octopus page is erroneous, please correct this as soon as possible. With Gratitude to Wikipedia for solving its own riddle. Thomas G. Higgins 67.158.204.253 (talk) 01:35, 21 October 2012 (UTC) Additionaly, if, and it is a big if, if Octopus is a Third Declension Latin-Greek assumed word, the following forms would be the case Octopus, Octopuses; if that is if the gender of the word itself is believed to be masculine. There is no evidence, as yet, that the word is of the masculine Greek form, so, it may be that the gender question is the cause of the confusion, not, to mention the possibility that the word is a feminine gender Greek word with the -OS/-US ending assumed into Latin in the 2nd Declension, resulting in Octopus/Octopi. SIde by side then: Octopus/Octopi is 2nd Declension Latin/feminine Greek into Latin; Octopus/Octopuses is 3rd Declension masculine Greek into Latin; The Etymology section cheerfully assumes that Octopus is a third declension masculine Greek into Latin rather than the more likely straight translation of the Greek word into Latin ending in -OS/-US. If, the compound Greek word Octo+Pous actually makes the word a masculine case by the possible fact that pous is a masculine word, then, maybe the argument is solved as a masculine translation into Latin. If not, then, it follows that the form of the word dictates the translation into Latin, meaning that Octopous is actually a feminine Greek word. That is something which I will get back to you all about later after I study Greek Declension. [edit] — Preceding unsigned comment added by 67.158.204.253 (talk) 02:07, 21 October 2012 (UTC)

[AHED-octopus-1] William Morris (ed.). "octopus". American Heritage Dictionary of the English Language.

[OED-octopus-2] "octopus". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)

[3] William Morris (ed.). "octopod". American Heritage Dictionary of the English Language.

[4] "octopod". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)

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