From Wikipedia, the free encyclopedia
Jump to: navigation, search
Good article Mollusca has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it.
October 27, 2008 Good article nominee Listed
WikiProject Gastropods (Rated GA-class, High-importance)
WikiProject icon This article is within the scope of WikiProject Gastropods, a collaborative effort to improve the coverage of gastropods on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
 GA  This article has been rated as GA-Class on the project's quality scale.
 High  This article has been rated as High-importance on the project's importance scale.
Taxonomy: For all marine species, Project Gastropods uses the taxonomy in the online database WoRMS. When starting a new article, do not use sources of taxonomic information that predate the 2005 revision for all gastropod groups. If you need help with any aspect of an article, please leave a note at the Project talk page.
WikiProject Animals (Rated GA-class, High-importance)
WikiProject icon Mollusca is within the scope of WikiProject Animals, an attempt to better organize information in articles related to animals and zoology. For more information, visit the project page.
 GA  This article has been rated as GA-Class on the project's quality scale.
 High  This article has been rated as High-importance on the project's importance scale.

Giant squid reference[edit]

Shouldn't intelligent invertebrates be qualified since none have been observed alive (except their juveniles recently). Instead, perhaps it could be stated "octopus and squids are among the most intelligent invertebrates. The giant squid is the largest invertebrate, but only the tentacles and carcasses of the adults have ever been observed.. Something along those lines. --rgamble

I agree completely. Do you want to make the change? AxelBoldt~

I've done so. Minor nit, and the extrapolation was probably valid but... you never know. ;) --rgamble

I don't think it would do any harm to include a list of the different mollusks with links to their articles. Anyone? palefire

No I don't think that would be a bad idea. Avatar of Nothing 21:29, 17 March 2007 (UTC)Avatar of Nothing


Pretty much every occurrence of the term in the article itself is "mollusc" not "mollusk"; would it be more appropriate to move the page to Mollusc? Shimgray | talk | 20:20, 17 December 2005 (UTC)

Check the history, it seems to be one of those US vs The Rest spelling fights. --Paul 14:42, 26 December 2005 (UTC)
Ah, yes. What links here shows about even for mollusk/mollusc, so no help there, but the technical term is "mollusca"... huh. Either way, it'd be nice for the article to agree with the title. Shimgray | talk | 15:28, 26 December 2005 (UTC)
How about Mollusque ... which hasn't been used for centuries? I agree that the title should agree with the spelling used in the article. My preference is for mollusc but it's not up to me. According to WP:MOS, we should settle on whatever was the first spelling. Jimp 10Feb06
Looking back, it was originally a redirect to Mollusca, then that page was moved here "to the English title". Shimgray | talk | 16:04, 10 February 2006 (UTC)
Then looking back at the history of Mollusca shows something quite interesting. The very first comment comes from User:TrickyP who writes "Changed mollusc to the preferred spelling, mollusk." I can't see any eariler version but presumably it had mollusc. I don't know whether Tricky was aware that mollusk is not the preferred spelling outside the US. Jimp 06:29, 15 February 2006 (UTC)
I vote for Mollusc. There are more non-Americans than Americans. And science is international.
I vote for Mollusk. "sk" is usual, i.e. "desk", "task", "whisk", "risk", "mask" etc., "sc" is not i.e. "disc" (the only example I can think of). 19:16, 1 April 2006 (UTC)
The difference between "--sk" words and "--sc" words is etymology. The ones with "--sc" usually come from the Greek or Latin, the ones with "--sk" are usually Germanic, or else French, as a replacement for "--sque". So "disc" from "diskos", a Greek word for the round throwing object, spelled in Latin as "discus". Compare "whisk" with "viska", the same word in Swedish, or "mask" with "masque", almost the same word in Old French!!!! "Mollusc" was coined by Linnaeus from the Latin but the original Latin word "molluscus" related to "mollis", meaning soft (as in the eider dusk, Somateria mollissima, who's species name means "most soft", a reference to its feathers). For whatever reason American English has replaced the "--sc" endings with "--sk" while British English keeps them. Since the word has no great antiquity, there isn't really a traditional one and both are used in science (though American journals tend to favour American spellings, and British journals British spellings). I happen to prefer mollusc because it is closer to Mollusca, but really I couldn't care less. Cheers, Neale Neale Monks 21:08, 9 November 2006 (UTC)
FWIW, I'm American and I was faintly startled to discover that "Mollusk" is supposedly our favored spelling. I've never seen any authority, U.S. or otherwise, spell it with the K. Does somebody have some citations for scientific publications using this spelling?Nentuaby (talk) 00:53, 11 April 2008 (UTC)
The following discussion is an archived debate of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the debate was move. —Nightstallion (?) Seen this already? 14:33, 22 April 2006 (UTC)

Requested move[edit]

MolluskMollusca |→ Spaully°τ 00:18, 17 April 2006 (GMT)

Rationale: Per WP:MOS which prefers the use of nationally neutral terms ("Where varieties of English differ over a certain word or phrase, try to find an alternative that is common to both." - see also Airplane and Aeroplane), I am posting a request at WP:RM to move this page to Mollusca, the name of the phylum this page deals with. I tried to move it myself, but the previous edit history at Mollusca dissallows this. All of your input would be very welcome. |→ Spaully°τ 00:12, 17 April 2006 (GMT)


Add *Support or *Oppose followed by an optional one-sentence explanation, then sign your opinion with ~~~~
  • Support. |→ Spaully°τ 00:23, 17 April 2006 (GMT)
  • Oppose. Should we move Cat to Felis, Dog to Canis, Lion to Leo, etc?? Georgia guy 00:30, 17 April 2006 (UTC)
  • Support. WP:TOL advocates use of common names where they exist (although I'd have preferred the spelling mollusc, but it's too late for that now. --Stemonitis 13:21, 20 April 2006 (UTC) Hang on, I've just re-read the arguments. A nationally neutral term like "Mollusca" seems justified in this case. --Stemonitis 13:23, 20 April 2006 (UTC)
  • Support. While it Wikipedia's policy certainly does prefer the usage of common name, this seems like a reasonable time to make an exception, as a compromise between two national spellings, however, we will still be left with the decision of which term to use in the body of the text, because, while mollusca makes a decent article title, it doesn't work well as a noun in a sentence.Cerealkiller13 16:21, 20 April 2006 (UTC)
  • Support. Bactram 15:38, 21 April 2006 (UTC)


Add any additional comments

Georgia guy - this move is because American english uses 'mollusk ' whereas the rest of the world uses 'mollusc '. There is no such difference with dog and cat. Given this, please read this part of the MOS for an explanation. |→ Spaully°τ 10:04, 17 April 2006 (GMT)

In response to Cerealkiller13's query about which spelling to use - there seems to be no reason to change the spelling from the current one (whatever that might be), provided it's consistent. --Stemonitis 07:24, 21 April 2006 (UTC)
The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.


Recent studies have found that the collosal squid is now the biggest inverterbrate and I thought i'd just let you know.

How Many Species?[edit]

How many species of Mollusc are there? Phylum says 70,000. The introductory para says 112000, with a reference. Later on, the article says 250000. Can someone who knows the correct number please fix this? Thanks!

Short review about how many mollusca species exist is at Unfortunatelly it is in Czech language. It is my article, I can translate it if you want. I have counted 82 067 species. --Snek01 18:40, 22 October 2006 (UTC)

Recent symposium volume says about 200,000 species. Reference is:

  • Ponder, Winston F. and Lindberg, David R. (Eds.) (2008) Phylogeny and Evolution of the Mollusca. Berkeley: University of California Press. 481 pp. ISBN 978-0520250925.

My suggestion is to go with this total. I have placed this in the taxobox, but other numbers are sprinkled throughout the article. --Wloveral (talk) 02:54, 24 May 2008 (UTC)

There still remains wildly differing numbers of extant mollusc species in the article: ca100,000, ca200,000, >250,000, and 160,067. Can someone please rationalise this. In particular, the Classification section contradicts itself. GrahamBould (talk) 19:34, 4 July 2008 (UTC)
Hi GrahamBould. I've put the same question down below together with estimates from two different student textbooks. I'm happy to change the article to one or the other but would quite like input from someone with expertise!  :-) --Plumbago (talk) 06:04, 5 July 2008 (UTC)

Science = Mollusca/Mollusk[edit]

A mollusk come from a Latin word MOLLUS that means " soft".

A coelom is a fluid filled cavity that develops within the mesoderm.

A mollusk has a soft body from a Latin word mollus meaning soft which is generally protected by a very hard calcium containing shell.


Im not sure where to put this, some authors class this as a seperate class and not a gastropod like the new classification! Where can it go? Enlil Ninlil 04:38, 12 January 2007 (UTC) site[edit]

Firstly, it's a commercial site, so should be handled carefully. Secondly, it contains several mistakes:

  1. The tree structure implies Aplacophora and Polyplacophora are not Molluscs
  2. Monoplacophora and Scaphopoda are shown outside of Conchifera, when they're usually part of it
  3. Below the Conchifera branch of the tree, incorrect relationships between the groups are implied

Some of these points are probably a feature of the tree design (and the need to have it fit on a webpage) rather than any misunderstanding on the part of its creator. However, as the page offers very little useful information and is misleading, I'm removing it again. Sorry, --Plumbago 18:05, 25 January 2007 (UTC)

Slime / excretions[edit]

I think someone (preferebly an expert) should put something up about what is in the slime that snails produce and what is its function. Superruss.


I think that most people that are typing in Mollusca they will be looking for the Bivalve Mollusk, I think there should be a redirect for the people that are looking for the commonly named [Bivalve] Mollusk. Russianfriend742 15:29, 2 May 2007 (UTC)

Big Squids[edit]

The giant squid, which until recently had not been observed alive in its adult form,[3] is one of the largest invertebrates; however the colossal squid is even larger.

Wouldn't it be easier just to say that the colossal squid was the biggest? —The preceding unsigned comment was added by (talk) 23:51, 2 May 2007 (UTC).

Mollusc shells[edit]

The animal shell article, although better than it was, is still in dire need of an expert's help. Would anybody care to have a go at cleaning up the "Mollusc" section there? My inclination is to use Wikipedia:Summary style, leaving a paragraph or two at Animal shell with a brief overview of things that are common to all mollusc shells, then move more of the chemical and anatomical details to a separate article -- perhaps at sea shell (currently a redirect). That article, in itself, could be a summary of Gastropod shell, Bivalve shell, etc.

Anyway, I've done what I can; thank you if you can provide further help! — Catherine\talk 16:55, 23 June 2007 (UTC)

Pain and Nerves[edit]

Do molluscs have nerves? Do they feel pain? —The preceding unsigned comment was added by AThousandYoung (talkcontribs) 21:25, August 22, 2007 (UTC).

The answer to the question of whether molluscs feel "pain" will depend on how you choose to define the term, but they certainly have a sense of touch, and when they encounter harmful touching they will react accordingly.

How do molluscs breathe on land?[edit]

It would be useful if this article could contain a description of how land-based molluscs, or beached acquatic molluscs, breathe: see, for example [1], [2] -- The Anome 09:20, 29 October 2007 (UTC)

Molluscan classes[edit]

How's about this for an alternative to the current list of molluscan classes?

Class Major organisms Extant species Distribution
Caudofoveata worm-like organisms 70 deep ocean
Aplacophora solenogasters, worm-like organisms 250 deep ocean
Polyplacophora chitons 600 rocky marine shorelines
Monoplacophora limpet-like organisms 11 deep ocean
Gastropoda abalone, limpets, conch, nudibranchs, sea hares, sea butterfly, snails, slugs 40,000 - 150,000 marine, freshwater, land
Cephalopoda squid, octopus, cuttlefish, nautilus 786 marine
Bivalvia clams, oysters, scallops, mussels 8000 marine
Scaphopoda tusk shells 350 marine
Rostroconchia fossils; probable ancestors of bivalves extinct
Helcionelloida fossils; snail-like organisms such as Latouchella extinct

This information is little messy in the article at present, so I figure a table might add some structure. I've removed some information about the example gastropods, but I reckon that should really be picked up by the gastropod article itself. Also, I've juggled the order of the classes to follow the ancestral order illustrated (though I've stuck the extinct species out on their own at the end). Anyway, if people like this (or no-one replies), I'll import this into the article. Please feel free to make edits to it. Cheers, --Plumbago (talk) 08:00, 13 May 2008 (UTC)

Excellent. I wonder whether the Distribution could be expanded to indicate whether free swimming or sedentary (may be too difficult given that scallops can swim too!!). Cheers GrahamBould (talk) 22:38, 15 May 2008 (UTC)
Hi there. Thanks for taking a look at the table! I suppose it could be expanded in the way you suggest, but I'd concur about the difficulty vis-a-vis even sedentary organisms swimming. Anyway, I'll add the table above to the article. --Plumbago (talk) 11:44, 20 May 2008 (UTC)

Further to the above, and since I'm wildly out of date, I've had a poke around a couple of modern-ish textbooks and now have a couple of alternative schemes for classification at the class level:

Class Extant species Class Extant species
Chaetodermomorpha 70 Aplacophora ~370
Neomeniomorpha 180
Monoplacophora  ? Monoplacophora ~25
Polyplacophora 550 Polyplacophora ~1000
Gastropoda ~77000 Gastropoda ~70000
Bivalvia ~20000 Bivalvia ~20000
Scaphopoda ~350 Scaphopoda ~900
Cephalopoda ~650 Cephalopoda ~900
Total ~98800 Total ~93195

The scheme on the left stems from:

Barnes, R.S.K., Calow, P., Olive, P.J.W., Golding, D.W. and Spicer, J.I. (2001). The Invertebrates, A Synthesis (3rd Edition), Blackwell Science, UK.

The scheme on the right stems from:

Brusca, R.C. & Brusca, G.J. (2003). Invertebrates (2nd Edition), Sinauer Associates Inc., MA, USA.

Neither seems to include the wholly extinct classes, the Rostroconchia and the Helcionelloida, although Brusca & Brusca (2003) do refer to around 70000 extinct mollusc species. Anyway, I'll try to synthesise this information into the main article, but wanted to log it here (a) so I didn't lose it, and (b) to attempt to elicit more informed views of molluscan taxonomy! Cheers, --Plumbago (talk) 14:49, 20 May 2008 (UTC)


There's no mention of any kind of reproduction in this article, which I think is an important part of any subject related to biology. Maybe you could do something like the article for sponges, where there is a section for "Ecology and Reproduction". Hippie Metalhead (talk) 01:58, 16 May 2008 (UTC)

Sources, etc.[edit]


  • Evidence for a clade composed of molluscs with serially repeated structures: Monoplacophorans are related to chitons (2006) : "Molluscs (snails, slugs, clams, mussels, squids, octopuses, chitons, etc.) exhibit the largest disparity of all animal phyla and rank second behind arthropods in species diversity." "In fact, the disparity of mollusc body plans is so great that it is quite difficult to find a single trait shared by all seven classes of molluscs (13)."
  • From Brusca & Brusca. Invertebrates (2nd ed.). , p 702:
    • Bilateral symmetry - hmmm
    • Coelom limited to small spaces around nephridia heart & part of intestine - I'll have to check how that differs from e.g. arthropods.
    • Principal body cavity haemocoel - applies also to arthropods.
    • Dorsal concentration of viscera (visceral mass) - might be the main one, IIRC one source I found was confident only about this one.
      apparently not in aplacophora (Ruppert et'al, Inv. Zoo. p291)
    • YesY Body covered by mantle; mantle cavity contains ctenidia, nephridiopores, gonopores & anus - I'll check out aplacophora, they're "the usual suspects".
      mantle; mantle cavity contains ctenidia, nephridiopores, gonopores & anus (Ruppert et'al, Inv. Zoo. p291)
    • YesY Mantle shell glands secrete calcareous spicules, plates or shells - ditto
      aplacophora secrete spicules (Ruppert et'al, Inv. Zoo. p291)
    • Heart in pericardial chamber, separate ventricle & atria - might be promising.
      pericardial chamber possibly, tho looks like a rather general requirement. separate ventricle & atria questionable in aplacophora (Ruppert et'al, Inv. Zoo. p291)
    • Large, well defined muscular foot, often w/ creeping sole - would include our Cambrian conundra.
    • Buccal region w/ radula - not in bivalves or aplacophora.
      aplacophora have buccal cavity, but 20% lack radula (Ruppert et'al, Inv. Zoo. p291). Bivalves have no buccal cavity!
    • Complete gut with regional specialisation, incl. large digestive ceca - promising, must check aplacophora.
      no caeca in some aplacophora (Ruppert et'al, Inv. Zoo. p291)
    • Large complex metanephridia - must check what this means!
      aplacophora no nephridia (Ruppert et'al, Inv. Zoo. p291)
    • Protostomeus embryos - hmmm
    • Trochophore larva, usually veliger - hmmm.
  • From Ruppert et'al, Inv. Zoo. (general: p 284-291. aplacophora: p291-292; bivalves: p 396ff)
    • YesY 2 pairs of main nerve cords, except 3 in bivalves.

-- Philcha (talk) 21:39, 29 September 2008 (UTC)

If you want a "definition" of mollusca, then why not take the Budd approach (Budd & Jensen 2000, critical reappraisal of the bilaterian phyla) and define it as "the smallest clade that contains the scaphopoda and aplacophora"? This "crown group" definition is the best way of rigidly defining a phylum with minimal subjectivity. Martin (Smith609 – Talk) 23:53, 2 October 2008 (UTC)
3 reasons:
  • I have not been able to access Budd & Jensen (2000) "Critical reappraisal of the bilaterian phyla" - IIRC it's one of the older Lethaia issues that are harder to access online.
  • I'd have to explain "scaphopoda" and "aplacophora" before explaining basic molluscan anatomy. Using such a definition without immediate explanation is OK for scientific journals, but not for an encyclopedia.
  • Phylogenetic definitions are just summaries of cladograms, which are hypotheses about ancestry. I wanna see the evidence! (waaAAAAH!) For example I had a similar discussion a while ago about the definition of "dinosaur", in which I pointed out that for a long time in the mid-1900s dinos were regarded as polyphyletic, and that if that view came round again a phylogenetic definition of "dinosaur" would collapse. -- Philcha (talk) 14:30, 5 October 2008 (UTC)

Lower Cambrian bivalves[edit]

Hi, would you happen to have a copy of

  • Pojeta, J. (2000). "Cambran Pelecypoda (Mollusca)". American Malacological Bulletin 15: 157-166.

that I could take a look at, or could you provide a quote to back up the presence of LOWER Cambrian bivalves? From the abstract I get the impression that the lower Cambrian stuff is interpreted as brachiopods, and the only bivalves are from middle/upper Cambrian times. Thanks, Martin (Smith609 – Talk) 13:21, 5 October 2008 (UTC)

No, took the ref in good faith from elsewhere (no comments on my sanity, please!). You've just motivated me to search and:
In scientific writing it's usually considered bad practise to cite a reference you haven't read yourself. For WP's purposes it is best to cite the source you found the fact in; if you wish you could present it as "Smith 1999, cited in Jones 2001". Not only is this a more honest approach, but it makes it easier for other editors to verify facts! Thanks for the new refs though. By the way, I suspect that a GA reviewer will take issue with the length of the lead; you may want to shorten it before you do go through the nomination process. Martin (Smith609 – Talk) 17:03, 5 October 2008 (UTC)
Also it strikes me that there's not much on ecology. Perhaps this is difficult with such a diverse group, but you may be able to include half a paragraph on each class? Martin (Smith609 – Talk)

GA Review[edit]

This review is transcluded from Talk:Mollusca/GA1. The edit link for this section can be used to add comments to the review.

I am reviewing this Good Article nomination and should have the full review up shortly. Miss Madeline | Talk to Madeline 05:06, 22 October 2008 (UTC)

  1. It is reasonably well written.
    a (prose): b (MoS):

#:: Some sections have bracketed definitions of technical terms. While this is necessary to an extent, perhaps it might be better to simply have just links? (Or maybe it isn't. I'll leave the decision about whether to change that up to you, and I won't consider it in deciding whether to pass or fail the article; it's just a suggestion)

  1. Spelling mistakes exist, please fix them.
  2. It is factually accurate and verifiable.
    a (references): b (citations to reliable sources): c (OR):

#::The link in reference 8 does not directly link to its intended target (it redirects me to a main journal page, not the article in question. Please fix this if it is possible to do so.

  1. Reference 8 needs its formatting fixed
    References 9 and 10 are duplicates, and need page numbers
    References 4 and 11 are duplicates
    References 1 and 24 are duplicates
    The doi in reference 40 is a broken link
    Reference 33 is formatted differently from others
    Fix reference 57
    The doi in reference 51 is a broken link
    Reference 62 is a broken link
    Reference 69 should be fixed
    "The "generalized mollusc" has two paired nerve cords, or three in cephalopods." [in lead] and "There are at least two pairs of main nerve cords (three in bivalves[13])" [in Definition]. A contradiction.
  2. It is broad in its coverage.
    a (major aspects): b (focused):
  3. It follows the neutral point of view policy.
    Fair representation without bias:
  4. It is stable.
    No edit wars etc.:
  5. It is illustrated by images, where possible and appropriate.
    a (images are tagged and non-free images have fair use rationales): b (appropriate use with suitable captions):

#:: Image:Schistosomiasis_itch.jpeg needs it's caption fixed

  1. Overall:

Overall this is very close to GA. It just needs a little work to push it over the boundary. Miss Madeline | Talk to Madeline 06:15, 22 October 2008 (UTC)

I fixed the typos and the image caption and have crossed out resolved concerns. I'll wait for the remaining issue to be resolved, although I expect to promote this article soon. Miss Madeline | Talk to Madeline 22:47, 22 October 2008 (UTC)
Thanks! If the editor who recommended Ponder & Lindberg (2008) doesn't come through by Monday evening, I'll replace the stats with the ones in my text book (2005) - global species counts are just educated guesses any way. -- Philcha (talk) 23:21, 22 October 2008 (UTC)

Hi, Miss Madeline, thanks for stepping up to review this.

Bracketed definitions of technical terms[edit]

I'm quite keen on Wikipedia:Make technical articles accessible, and think that immediate explanations hold less risk of breaking the reader's train of thought. I've also found in the past that articles that might appear to be suitable link targets have probems - stubs, too technical and, specially with anatomical terms, often too human- / vertebrate oriented. In one extreme case a buddy and I got Anus moved to Human anus because the content was quite inappropriate for invertebrates! Just wait until we get on to Coelom - the medics have few surprises coming! -- Philcha (talk) 09:18, 22 October 2008 (UTC)


Will do simplest first, as handling dups will change numbering: -- Philcha (talk) 09:18, 22 October 2008 (UTC)

  • "The link in reference 8 7 does not directly link to its intended target (it redirects me to a main journal page, not the article in question."
Must have been added by someone trying to be helpful, as it didn't use a citation template - it does now, and I found a link to free full PDF.
  • "Reference 8 needs its formatting fixed"
  • "The doi in reference 40 is a broken link"
Dunno what's happened, can't find the title in Google. Different journals have different approaches to keeping stuff online, and I've noticed Lethaia's policy is ungenerous. DOI removed.
  • "Reference 33 is formatted differently from others" for some reason it used {{tl:citation}} rather than {{cite journal}}. Now uses {{cite journal}}. IMO it's a bug in the system that the 2 templates give slightly different outputs, they should never have been allowed to diverge.
  • "Fix reference 57"
Oops! Fixed.
  • "The doi in reference 51 is a broken link"
I notice the correct DOI has [...] while the incorrect one had [[...]] Fixed. Do you know of any bots that that attempt to fix wikilinks?
  • Reference 62 is a broken link"
Publisher consolidated 3 pages but failed to add 301 redirect (grrrrr!). Fixed.
  • "Reference 69 should be fixed"
Fixed -- Philcha (talk) 09:37, 22 October 2008 (UTC)


  • "References 9 and 10 are duplicates, and need page numbers"
They're separate dictionary entries, so keywords are more helpful than page nums as the content will also be present in later editions. {{cite book}} does not recognise the "contribution" param (grrRR!), changed to {{citation}}. -- Philcha (talk) 09:37, 22 October 2008 (UTC)
  • "References 1 and 24 are duplicates"
De-duplicated. Ref 2 is the same. There's a further problem - the ref is incomplete as as it's a compilation and the author & title of the contribution are not given - some past editor has failed to do their chores (grrRRRRRRR!). I don't have the book and Google Books is no help in this case (gives ordering details only, no extracts). I've asked the person who recommended refs to Ponder & Lindberg to help. -- Philcha (talk) 09:59, 22 October 2008 (UTC)
Removed refs to Ponder & Lindberg (2008) as no-one's come forward with the required info. Added 1 source for species counts and others for descriptions and habitats in "Classification" section. Species count goes down from Ponder & Lindberg's 250,000 to "only" 93,000. The range I found while searching was generally 70,000 to 100,000. The source I used specifically says "described species", i.e. recognized in scientific publications, so at least I know what the counts mean. I can only assumed the figures quoted from Ponder & Lindberg (2008) include a guesstimate of undiscovered species, which would be rather speculative & subjective.
Also removed class Tentaculita† from taxobox as not mentioned in any of the refs I've seen. -- Philcha (talk) 10:08, 27 October 2008 (UTC)
  • "References 4 and 11 are duplicates"
Yes, they were dupes, but not any more. A page num is given (702), the problem is that the template just shows the number without identifying it as a page. IMO this is a template bug. For example if this article is translated into some language whare "p." is not the abbreviation for "page" the translators have to change all page nums in refs, which makes the use of templates pointless. I'm aware of this problem in {{cite book}}, {{cite journal}} and {{citation}}, and have proposed a restructuring of citation templates to avoid such problems by making the "public" citation templates just check the params and then pass them to a common formatting template, but bureaucratic inertia has prevailed. -- Philcha (talk) 10:15, 22 October 2008 (UTC)

Content problems[edit]

  • "The "generalized mollusc" has two paired nerve cords, or three in cephalopods." [in lead] and "There are at least two pairs of main nerve cords (three in bivalves[13])" [in Definition]. A contradiction.
It's a fair cop guv. Lead now says "bivalves". -- Philcha (talk) 14:55, 22 October 2008 (UTC)

Question about "related Wiki projects"[edit]

IMO the related projects add no value whatever to this article, and will just put readers off the related projects. This would be a shame, as they do sometimes add value, see e.g. Howard Staunton. I'd like to remove the "related Wiki projects" boxes frmo this article. What do you think? -- Philcha (talk) 09:32, 22 October 2008 (UTC)

I assume you mean the box near the end linking to searches of "Mollusca" in the Commons, Wiktionary etc. In my opinion the big box linking the searches can be removed, but the smaller boxes could stay with a link to Mollusca on the commons added, but I won't fail the article over this. Miss Madeline | Talk to Madeline 22:47, 22 October 2008 (UTC)
You're right about the link to Commons, I've added it, thanks! Deleted the box near the end linking to searches of "Mollusca" in ... The dichotomous key thing will be good for school kids. Wikispecies is deeply unimpressive, but I'll give it the benefit for now. -- Philcha (talk) 23:17, 22 October 2008 (UTC)


I feel that all concerns have been addressed, so I am promoting the article. Great job and keep up the good work! Miss Madeline | Talk to Madeline 22:12, 27 October 2008 (UTC)

Lead length[edit]

The article's lead seems rather long to me. Could it be separated into a short lead (the first paragraph kind-of covers this) followed by a long "overview" / "introduction" / "general biology" section (that includes the rest of the text)? Some tweaking would probably be necessary, but I reckon it would improve the article's overall appearance significantly. Cheers, --PLUMBAGO 10:34, 27 October 2008 (UTC)

P.S. I now notice that other phylum articles like Arthropod also have what I interpret as overlong leads. I still think the intro (now, "intros") could be reformatted, but I won't rush to alter the one here. --PLUMBAGO 11:48, 27 October 2008 (UTC)
Hi, PLUMBAGO. I'm a little concerned about the length of the lead, and I wrote it. Part of the problem is summarising the key anatomical features and mechanisms of invertebrates, with which most readers will be less familiar than they are with vertebrates (especially with all the dinosaur programmes on TV). The other is summarising the diversity of forms across a whole phylum - especially as molluscs is the most disparate, ranging from brainless, sessile filter feeders to intelligent and very mobile hunters. Interaction with humans is another area that's difficult to summarise more brifely than in the main text. If you want to set up some try-outs at 1 or more sub-page of your User page and link to them here, I'll be happy to work with you on a more concise lead for Mollusc and / or Arthropod. -- Philcha (talk) 12:20, 27 October 2008 (UTC)
Hi Philcha. Thanks for getting back to me. Just to be clear, my concerns are only those of style (c.f. WP:LEAD). I like the text, but was just wondering about the word-count balance of the article's various portions. Your suggestion about having a stab at an alternative in my userpage is a good one. I'll try to do that if I find the time. I really just wanted to flag up the (IMHO) overlong lead because I noticed that the article's being prepped as a good article. Cheers, --PLUMBAGO 12:44, 27 October 2008 (UTC)
Hi, PLUMBAGO, the issue about the lead has become less urgent, as Talk:Arthropod/GA1 has just concluded that leads for articles of such wide scope should be treated as WP:IAR. --Philcha (talk) 19:47, 10 November 2008 (UTC)

"Generalized mollusc" and foot adaptations[edit]

I'm not happy about this edit (18:47, 10 November 2008) in section "Generalized mollusc". The preceding section "Definition" summarises some of the differences, including that in cephalopods the foot becomes a set of arms. The problem with molluscs is that they are very disparate phylum, which is why most sources start with a "generalized mollusc" or "hypothetical ancestral mollusc" ("HAM" to its friends), which strongly resembles an untorted gastropod. Introducing specialisations of one feature / subsystem opens the door to the introduction of others, e.g. cephalods have camera eyes, jet propulsion, colour-changing, large brains, venomous beaks mounted on powerful buccal "turrets", indirect fertilisation, simpler digestive systems, and a variety of "shell" forms - and they are just one of 7 or eight extant classes. A better approach would be to summarise the specialisations by class in section "Classification", but even this would make an already long article even longer. I suggest the specialisations should be dealt with in articles on the relevant classes. --Philcha (talk) 19:42, 10 November 2008 (UTC)

Molluscs in popular culture[edit]

I've removed this as it has no supporting citations --Philcha (talk) 16:09, 22 November 2008 (UTC)

"The Mollusk" is a nautically themed 1997 concept album from the band Ween


A section on the diet(s) of molluscs would be helpful and their position in various ecosystems. (talk) 15:53, 6 January 2009 (UTC)

I sympathise, but molluscs are so disparate in form and lifestyle that there's not much to say at this level, rather than in articles about particular groups of molluscs. I'm not aware of any ecological roles of sub-groups that are so important that they deserve mention in the article about the whole phylum - unlike arthropods, where pollinating insects are hugely important and blood-sucking insects and mites spread serious diseases, or cnidarians, where corals create their own ecosystems and are an important influence on ecosystems in-shore of their own location. However if you can identify specific points about molluscs that are of similar importance, that would be welcome - especially if you can specify sources of the information (see WP:V and WP:RS). --Philcha (talk) 16:49, 6 January 2009 (UTC)

The Aculifera[edit]

There is no mention in the article about the subphylum Aculifera, ie, the groups having; "spines or spicules" the best of my knowledge it includes:

Aplacophora, Polyplacophora,

Then the conchifera include everything else.

I think this should be included :-). —Preceding unsigned comment added by (talk) 15:09, 9 January 2009 (UTC)

Aculifera are mentioned in the cladogram in section Phylogeny. As far as I can see (after consulting 2 textbooks and some journal articles), the Aculifera are not a recognised sub-group in their own right but of of two proposed ways of grouping the recognised sub-groups. --Philcha (talk) 15:21, 9 January 2009 (UTC)

see it now. I am a marine biology student and molluscan taxonomy has given me a headache, and apparently I'm not the only one. The Wikipedia article has the two proposed taxonomic possibilities. On my notes, which I now wish were more concise I've just written that the aculiferans are divided into the aplacophorans and the polyplacophorans then the conchifera include everything else. My textbook doesn't have a lot to say on it other than a rambling rhetoric as to how scientists have disagreed with each other since Aristotle's time

Improper spelling change[edit]

Since "mollusk" was the spelling used in this article for more than five years after the earliest history, why is it that this spelling no longer even appears in the article proper, and is relegated to a mere mention in a footnote. How did this undiscussed change of national variety of English take place? Gene Nygaard (talk) 13:23, 29 December 2009 (UTC)

Yup, I agree with you! I put it back in again. Invertzoo (talk) 21:58, 21 April 2010 (UTC)

"Generalized mollusc" and its sub-sections[edit]

The "generalized mollusc" section up to 11:51, 20 December 2009 contained the content now in sections "Anatomy" and "Physiology" and their sub-sections - i.e. they are no longer in "generalized mollusc". This makes it less clear that the sub-sections apply to the "generalized mollusc", which is hypothetical, and not to any actual class of molluscs. The earlier structure mirrored the structure of the sources, especially Ruppert, Fox & Barnes. If there no good reasons for a structure different not supported by the sources, I will restore the earlier structure in about 2 weeks, around the end of Feb 2010. --Philcha (talk) 21:21, 17 February 2010 (UTC)

Composition of shell[edit]

The version of 09:41, 23 December 2009 had a short but simple account of the composition of the shell (in the "generalized mollusc"). The current version has removed the simple account, added a much more technical that needs to be rephrased to be read by non-specialists, and the 2nd half of this has no citation. If this is not improved, I will restored the earlier version. --Philcha (talk) 21:36, 17 February 2010 (UTC)

Possibly the engineering applications should in "Uses by humans". --Philcha (talk) 21:47, 17 February 2010 (UTC)

Content removed as above, may be good in "Uses by humans" if rephrased and fully cited: --Philcha (talk) 02:34, 3 March 2010 (UTC)

The mollusc shell is a biogenic composite material that has been the subject of much interest in materials science because of its unusual properties and its model character for biomineralization. Molluscan shells consist of 95-99% calcium carbonate by weight, while an organic component makes up the remaining 1-5%. The resulting composite has a fracture toughness ~3000 times greater than that of the crystals themselves.[1] In the biomineralization of the mollusc shell, specialized proteins are responsible for directing crystal nucleation, phase, morphology, and growths dynamics and ultimately give the shell its remarkable mechanical strength. The application of biomimetic principles elucidated from mollusc shell assembly and structure may help in fabricating new composite materials with enhanced optical, electronic, or structural properties.


Hi there. I see from the history of "Mollusk" (a redirect to here), that this page was moved on 22 April 2006 due to a requested move. Who's idiot idea was to move this article to the current name? I requested to move this article back to the original way it was, with a common (as opposed to scientific) name. We don't call the article about the Komodo dragon "Varanus komodoensis", the article about the Owls "Strigiformes", or the article about the Insects "Insecta". (talk) 15:59, 8 May 2010 (UTC)

But what is the common name - mollusc or mollusk? Mollusca is more neutral. Bazonka (talk) 10:32, 6 February 2011 (UTC)

Map of 'Mollusc output in 2005'[edit]

This map makes little or no sense; 'Bubbles' are defined as 'global distribution of mollusc output in 2005 as a percentage of the top producer (China - 10,883,190 tonnes)' - red, yellow and green bubbles represent 1%, 10% and 100%, respectively. Yet there are no yellow bubbles on the map, and China's '100%' bubble is a logical tautology, conveying zero information. Perhaps a table of 'Mollusc exporting countries' showing the actual annual tonnage of each producer would be more appropriate. No? —Preceding unsigned comment added by (talk) 01:32, 12 June 2010 (UTC)

Reference to broken DOI[edit]

A reference was recently added to this article using the Cite DOI template. The citation bot tried to expand the citation, but could not access the specified DOI. Please check that the DOI [[doi:10.1111/j.1096-0031.2009.00255.x ]] has been correctly entered. If the DOI is correct, it is possible that it has not yet been entered into the CrossRef database. Please complete the reference by hand here. The script that left this message was unable to track down the user who added the citation; it may be prudent to alert them to this message. Thanks, Citation bot 2 (talk) 03:49, 3 October 2010 (UTC)

Damage done by an edit on 25 August 2010[edit]

An edit at 09:37, 4 September 2010 changed the order of major sections and did other damage:

  • "Taxonomy" should not be first section, as it's too detailed for the beginning of the article. The previous version's first section "Diversity" covers well both the diversity (number of species) and disparity (number of "groundplans") of molluscs.
  • Some citations have been removed, in some cases leaving whole paras without citations, so the article after 09:37, 4 September 2010 did not comply with WP:V.
  • In "Taxonomy" the para "Synonymy has been a great problem. ... new marine species (many of which are mollusks) that are on average being described each year" IMO should be removed as:
    • The citation is inadequate, e.g. no name or publisher of the source.
    • I don't think it's relevant to the general reader.
    • The complaint about "for payment" sources is not a problem for the general reader nor to academics, most of whom have their subscriptions paid by their institutions.

Such a radical change as the one 09:37, 4 September 2010 should not have been been made without discussing it at this Talk page and waiting for responses. I was ill at the time, otherwise I would have reverted it instantly.

The simplest way to restore the damage would be to revert the article to 09:37, 4 September 2010 (by copy all of the old version and pasting into the current one). The alternative would be to change and check it para by para, which would be a lot of work and which I'm unwilling to do. --Philcha (talk) 11:40, 25 January 2011 (UTC)


Hi, Smith609, it's good to see you. I see you've inserted a new sub-section under "Ecology", about various feeding methods. Would that be better in the "Feeding" section? --Philcha (talk) 18:55, 22 April 2011 (UTC)

Mollusca vs Molluscae[edit]

Am I wrong in noticing the following?: Mollusca, which is in singular form, is the name for the Phylum. Shouldn't the Phylum name be the plural form Molluscae? I stumbled across this on wiktionary, so I'm assuming it's correct. Anybody have opinions? -- Myrddin_Wyllt 5/19/11 —Preceding unsigned comment added by (talk) 18:04, 19 May 2011 (UTC)

The word "Mollusca" is the feminine singular, derived from the Latin adjective molluscus, meaning soft of body or thin-shelled. (Compare with "mollis" = soft and mollipes = with a trailing gate and the English word mollify). The word Mollusca was adopted by Linnaeus in 1758 for a heterogeneous group of invertebrates, not originally including molluscs with shells. The French naturalist Cuvier then proposed this name in 1790 for what he called "les mollusques". Mollusca is considered neutral and plural. Molluscae makes no sense to anyone who has studied Latin. JoJan (talk) 18:30, 19 May 2011 (UTC)
According to wiktionary, mollusca is nominative singular while molluscae is nominative plural. Is wiktionary wrong? -- Myrddin_Wyllt 5/19/11
Mollusca is plural, see definition of mollusc from Oxford Dictionaries Online --Philcha (talk) --Philcha (talk) 07:49, 20 May 2011 (UTC)
Thanks for the help. It does appear that wiktionary is wrong -- Myrddin_Wyllt 5/20/11 —Preceding unsigned comment added by (talk) 20:44, 20 May 2011 (UTC)
I fixed wiktionary
Actually, "molluscae" would be a legitimate form in Latin (feminine genitive and dative singular and nominative plural); it's just that the scientific name "Mollusca" is a different form (neuter nominative plural). It seems that "Molluscae" was in somewhat common use for the phylum in the early 19th century; see [3]. Ucucha 23:29, 19 June 2011 (UTC)
This is quite amusing. The frequency for molluscae shows "molluscae" used in the early 19th cent, I suppose because the nascent commercial middle class' aspirations outran their Latin :-D The blue (correct) curve vividly shows how the early-mid 19th cent had a craze for zoology (and paleontology).
And thank for showing me Google's Ngrams, I may use it in an article I may create, where there are 2 spellings of a species name. --Philcha (talk) 08:33, 20 June 2011 (UTC)


I've restore the lead to the version of 11:28, 27 October 2008, the last edit before the article passed a GA review. I've got several phyla promoted to GA, and the reviewers independently concluded in each case that phyla are big subjects and 4 paras was too little to summarise the content. --Philcha (talk) 08:12, 12 July 2011 (UTC)

Is the diagram correct[edit]

Just an observation...Is the diagram of where the gills and the anus correct? It seems weird that the anus is right above its gills...that doesn't cause problems that it's breathing in its own poop water? It just seems sort of inefficient that the animal would have to filter that. (talk) 19:56, 13 February 2012 (UTC)

The diagram is of a hypothetical ancestral mollusk, so no-one knows if it is really "correct" or not. However, there are ways of getting around the fact that the anus opens above the gills -- the excreted material might quite likely be contained within a mucus thread for example. The thread tends to stay intact and therefore does not foul adjacent structures. Invertzoo (talk) 22:35, 11 July 2013 (UTC)
There is also this: the ctenidia/ gills are supposedly constantly circulating water over the anal opening (the incurrent water is low, the excurrent water is higher). This way, fresh water passes over the gills before passing over the anus. It's not as though the gills are flapping back and forth, mixing the excrement! They are circulating the water like a conveyor belt, with the dirty stuff last. Of course, having said all that, we are only talking about an imaginary animal— though even those should make sense to those who study them, so your question is certainly valid. KDS4444Talk 07:03, 5 March 2015 (UTC)


Do you wikipedians think it'll be okay to add a "see also" section with List of marine aquarium invertebrate species? Robert4565 (talk) 22:23, 17 March 2014 (UTC)

Attention needed on Evolution of the Mollusca[edit]

Currently a stub with a single reference, it could be replaced with the content here (Mollusca#Evolution) and expanded greatly. --Animalparty-- (talk) 10:25, 19 March 2014 (UTC)

Move it here and make it a redirect or else nominate it for deletion. The evolution of the animal does not need a separate article, in my opinion. KDS4444Talk 07:06, 5 March 2015 (UTC)
I disagree. Mollusca is a major Phylum with an extremely long fossil record (at least of the shelled species) and an extremely interesting and complex phylogeny. The fact that the evolution article is currently rather short does not mean it should be deleted or merged with this article. Invertzoo (talk) 22:37, 6 June 2016 (UTC)

External links modified[edit]

Hello fellow Wikipedians,

I have just modified 2 external links on Mollusca. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

When you have finished reviewing my changes, please set the checked parameter below to true or failed to let others know (documentation at {{Sourcecheck}}).

You may set the |checked=, on this template, to true or failed to let other editors know you reviewed the change. If you find any errors, please use the tools below to fix them or call an editor by setting |needhelp= to your help request.

  • If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
  • If you found an error with any archives or the URLs themselves, you can fix them with this tool.

If you are unable to use these tools, you may set |needhelp=<your help request> on this template to request help from an experienced user. Please include details about your problem, to help other editors.

Cheers.—cyberbot IITalk to my owner:Online 21:40, 2 April 2016 (UTC)

Repairing intro[edit]

I replaced this section of the intro, which had been deleted:

"the main body cavity is a hemocoel through which blood circulates; their circulatory systems are mainly open. The "generalized" mollusc's feeding system consists of a rasping "tongue", the radula, and a complex digestive system in which exuded mucus and microscopic, muscle-powered "hairs" called cilia play various important roles. The generalized mollusc has two paired nerve cords, or three in bivalves. The brain, in species that have one, encircles the esophagus. Most molluscs have eyes, and all have sensors to detect chemicals, vibrations, and touch. The simplest type of molluscan reproductive system relies on external fertilization, but more complex variations occur. All produce eggs, from which may emerge trochophore larvae, more complex veliger larvae, or miniature adults."

Invertzoo (talk) 21:50, 6 June 2016 (UTC)

Binary fission??[edit]

I just removed a sentence from the ancestral mollusc section stating that the early mollusca reproduced by "binary fission, much like a sea star." None of the associated references contained links that I could use to verify that claim, and none of the other references I found on line supported it either. Nothing about the shape or organ structures of this animal even hints that binary fission is remotely possible: it is depicted as having a single gonad and as releasing gametes through tubules within its mantle cavity located near the ctenidia— this is sexual reproduction (even if possibly hermaphroditic), not binary fission "like a sea star." If someone can provide a reliable source that actually says this, then I will gladly eat my hat! KDS4444 (talk) 04:39, 20 February 2017 (UTC)


  1. ^ Currey, J. D. (1999). "The design of mineralised hard tissues for their mechanical functions". The Journal of experimental biology. 202 (Pt 23): 3285–3294. PMID 10562511. 

Icons for cladograms[edit]

Solenogastres outline icon.png Caudofoveata outline icon.png Monoplacophora outline icon.png Polyplacophora outline icon.png Bivalvia outline icon.png Gastropoda outline icon.png Scaphopoda outline icon.png Cephalopoda outline icon.png

This set of icons could be useful for cladograms. --Snek01 (talk) 11:59, 14 May 2017 (UTC)