Talk:Larvacean

Fritillaria

The link Fritillaria directs to plants (or animal butterflies), which cannot be a larvacea. 77.58.120.15 (talk) 01:56, 5 January 2013 (UTC) Felix Müri

Fixed, it now points, ten years later, to Fritillaria (tunicate)! Chaotic Enby (talk) 16:16, 21 May 2023 (UTC)

Plastic particles

Larvacea transport plastic particles in the ocean. See: Kakani Katija et al, From the surface to the seafloor: How giant larvaceans transport microplastics into the deep sea, Science Advances (2017). DOI: 10.1126/sciadv.1700715 — Preceding unsigned comment added by 200.129.128.7 (talk) 18:42, 17 August 2017 (UTC)

neoteny

I believe that all of the evidence indicates that the entire Tunicate clade evolved from an ancestor whose adult form look like an adult Larvacean. Thus the Larvacea are not an example of neoteny, but rather are an example of a retained primitive trait. The book, The Evolution of the Vetabrates makes it clear that tunicates built on top of an ancestral adult form, which was similar to the form of the Larvacea. Nick Beeson (talk) 02:47, 4 March 2020 (UTC)

As it doesn't matter in Wikipedia what you think, but rather what reliable sources say, can you point to that book on-line and to some other quality sources that support that? To be fair, I am not aware of sources (I haven't looked) that would support the form of larvaceans being an example of neotony, so I am not arguing for restoring the note at this time. - Donald Albury 10:35, 4 March 2020 (UTC) Edited 10:40, 4 March 2020 (UTC)

A couple of sources describing larvaceans as neotenic:

• Williams, J. B. (January 1996). "Sessile lifestyle and origin of chordates". New Zealand Journal of Zoology. 23 (2): 111–133. doi:10.1080/03014223.1996.9518072. ISSN 0301-4223. "It is generally acknowledged that the larvaceans are neotenic tunicates, ..."
• Todd, C. D.; Laverack, M. S.; Boxshall, Geoff (June 20, 1996). Coastal Marine Zooplankton: A Practical Manual for Students. Cambridge University Press. ISBN 978-0-521-55533-3. Larvacea "includes ascidians that retain larval features in the adult form (i.e. neoteny)"

If there are sources of similar quality that, Even if the preponderance of sources argue against neoteny in larvaceans, I think a note is still ln order that the name "larvacean" is based on the resemblance of the adult forms to larvae. - Donald Albury 10:59, 4 March 2020 (UTC)

I just added it! Chaotic Enby (talk) 11:07, 7 April 2023 (UTC)

References

For whoever added the bottom two references (the ones that aren't cited in the text) are you sure that these weren't used in the text at all? For example, the Oikopleura dioica section has no cited sources. There seems to be an overall lack of cited sources on this article. --Babbo99 (talk) 16:54, 4 February 2021 (UTC)

Page title?

The common name for these creatures is "larvacean", but the valid scientific name is "Appendicularia", not "Larvacea". This page should either be moved to the common or scientific name (Larvacean or Appendicularia, both of which redirect here currently), instead of the article title being a rare junior synonym which is not used in many reliable sources. Chaotic Enby (talk) 15:26, 2 April 2023 (UTC)

The first sentence in the article has always included both "larvacean" and "Appendicularia" since the article was created in 2004. I'm not sure why the current title was chosen. The article should be named in accordance with Wikipedia:Naming conventions (fauna)#Use the most common name when possible. My question would be whether "larvacean" is common enough to mandate its usage over "Appendicularia" (I'm not sure how many readers will recognize either name). Let's wait a few days to see if there are any more comments (the title has been wrong for 19 years, what's a few more days). If and when we move the article, I can take care of the details. Donald Albury 17:45, 2 April 2023 (UTC)

No other reply yet, but based on the closest equivalent - the page for sea squirts is at Ascidiacea even though the common name is relatively well-known - I'd say we go for Appendicularia? Although on the other hand, most other chordate classes use the common name. Not too definitive about this one yet. Chaotic Enby (talk) 08:44, 7 April 2023 (UTC)

Just realized - Appendicularia is already a plant genus, plus a genus of larvacean inside the class Appendicularia itself. So to avoid more confusion, and to have a natural disambiguation, it would be ideal to have the page at Larvacean rather than Appendicularia. Chaotic Enby (talk) 16:52, 8 April 2023 (UTC)

And the plant is at Appendicularia (plant), so something like Appendicularia (Tunicate) is available. Appendicularia (plant) article was illustrated with an image of Oikopleura dioica. I have now removed it. Donald Albury 17:11, 8 April 2023 (UTC)

Yes, but Appendicularia (tunicate) wouldn't disambiguate between the class Appendicularia and the genus Appendicularia inside the class. What I propose would be having Appendicularia as a disambiguation page, with links to Larvacean (this page once moved), Appendicularia (plant) and Appendicularia (animal genus) - the last one being the destination of the link for the genus in the taxobox, which remains to be created but I'll try to do it. Chaotic Enby (talk) 17:37, 9 April 2023 (UTC)

How in hell did we end up with a genus Appendicularia in the class Appendicularia? I thought the naming rules prevented that (although I see that Worms is guite happy with it). You can just add a line to the DAB at Appendicularia after you create a page for the genus. Donald Albury 18:09, 9 April 2023 (UTC)

This made me realize that the authorship for the class, which I found on the French wiki since it had the one for the order too, is actually the authorship for the genus of the same name, and that the previous authorship for the class was probably the correct one. I don't know if there's a rule for not naming the class the name of a genus inside it, but I don't know if anyone even thought someone would try to do this before, so... Chaotic Enby (talk) 22:17, 9 April 2023 (UTC)

Finally found an actual good source for this one! https://www.dcceew.gov.au/sites/default/files/env/pages/81f491f3-4fc8-42d0-a92e-5dce256fd340/files/05-appendicularia.pdf

Chaotic Enby (talk) 10:26, 10 April 2023 (UTC)

Big rewrite

I'll probably reshuffle a big part of the article, as the sections "anatomy" and "feeding" both describe the house, leading to a clunky flow in the article. Plus a lot of interesting information from MBARI can be added, as well as the ecological impact of larvaceans on deep-sea ecosystems (and, more recently, of sending plastic down there) - these are really underrated and interesting creatures! Chaotic Enby (talk) 11:06, 7 April 2023 (UTC)

I had recently thought about combining the content about "houses", so I approve. :) Donald Albury 12:30, 7 April 2023 (UTC)

Speaking of which, I'm trying to find any reference for the authorship of Copelata as an order name but can't seem to find any? All sites I looked through indicate "no authorship information", would you have any clue about this? Chaotic Enby (talk) 17:44, 9 April 2023 (UTC)

Thanks to a tv-documentary on the excellent work of MBARI with some fascinating footage of Barthochodeaus (go see their laserscans of the houses!) I have been reeding up on these very interesting animals, and find the information rather limited, including this article. I have many questions about there positioning: Why are they included in the sub-phylym Tunicates and not set apart from that? Apperently they were once considered neotenic larvaes of Tunicates, but instead we have to conclude they are very basic chordates who have sort of remained their original bodyplan (just like Cephalochordates) over the last 600 million years, but have become specialised in building these mucus houses. So why are Cephalochordates now considered a seperate sub-phylum whereas Appendiculirians are included in Tunicates, is this only a historical mistake (and should they now be considered the closest relatives of Vertebrates, instead of the Cephalochordates who held that position when I had to read Buchbaum (just checked but nothing on appendicularians there) at university in the 80's)? If only simelarities of larvae are conclusive than frogs coudld be considered Tunicates too!

Are there genomic reasons to do so? If so please explain. When reading "The Invertebrate Tree of Live" on this subjects it states that whereas Cephlochordates have a very conservative genome, these animals have a very derived genome, but it doesn't explain how this relates to other Tunicates? As far as I can tell from these sources, there is just as much justification to say that both Vertebrates and Tunicates (not including appendicularians) are really very derived appendicularians? But probably there are plenty of competent biologist who can expand on these issues, so I would love to stimulate them to do so!--Codiv (talk) 10:41, 20 August 2024 (UTC)

Thanks a lot for your questions! I've actually seen (very rare) sources treating appendicularians as a separate subphylum, but they are usually grouped with tunicates, as they are sister groups from an evolutionary point of view, and both are able to produce tunicin (being the only animals able to do so).
For reference, the chordate phylogeny roughly looks like this:

Chordata	Cephalochordata Olfactores Tunicata Appendicularia Ascidiacea (incl. Thaliacea) Vertebrata

Chaotic Enby (talk · contribs) 11:42, 20 August 2024 (UTC)

Thank you for your fast reply and the phylogenitic tree!

I did try the link to tunicin, but it went to the general article on cellulose with nothing specific there on tunicin or tunicates whatever (or anything on the production of cellulose by animals). For what do appendicularians use tunicin? If this is the defining caracter, than please explain in the article. But I understand if I'm overasking, maybe much is still a matter of debate (and 1 fool can ask more than 10 scientist can answer ;-) Codiv (talk) 13:56, 20 August 2024 (UTC)

Yes, I should definitely expand on it in the article! Tunicin is the name given to cellulose secreted by tunicates, although the article on cellulose only has one line about it sadly. Appendicularians use it for their "house" alongside mucus, while tunicates use it for their tunic. Chaotic Enby (talk · contribs) 14:55, 20 August 2024 (UTC)