Talk:Krill

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This article is about the group of krill, important animals of the plankton. It covers the different species in all areas of the world, their taxonomy, geographical distribution, morphology, behaviour, life cycle, ecology and economy. I started the article in May 2003 and many contributed since, especially user:Lupo did a great job. Uwe Kils 23:49, July 9, 2005 (UTC)

Of the four listed possibilities for the word "krill", aren't the first three all the same? Antarctic krill is clearly just a type of krill, and that's what (baleen) whales eat. The only ambiguity seems to be between krill (the animal) and Krill (the fictional character). It strikes me that when someone uses the word "krill", they almost always mean the crustacean, and almost never the character (a google search gives the first non-crustacean entry on the second page, and that's an Australian band). Let's have the current Euphausiid article at krill, with a sentence at the end saying "Krill is also a character in ElfQuest..." Any objections?--Stemonitis 08:25, 8 Jun 2005 (UTC)

good idea Uwe Kils 10:52, Jun 8, 2005 (UTC)

Done. Let's see how it works. --Stemonitis 08:23, 9 Jun 2005 (UTC)

Hm. Don't know what you did, but the article was still at Euphausiid, and Krill was redirecting there. Our general policy is to have articles of animals at the common name, with the scientific name(s) redirecting there. I did the move, and expanded the Krill article, and moved that ElfQuest thingy over to Krill (disambiguation). Lupo 20:17, 15 Jun 2005 (UTC)

Contents 1 Filter feeding 2 Your work is appreciated 3 Taste? 4 FAC stuff 5 Keystone?

[edit] Filter feeding

Thanks a lot for your help, Uwe. I see you changed "These filters need to be very fine indeed, for krill feed primarily on phytoplankton, in particular on diatoms, which are unicellular algae" to "These filters can be very fine indeed, for Antarctic krill feeds..." and later on (in Ecology) you state that Northern krill feeds on larger zooplankton (and hence doesn't need such a fine filter).

Is this truly specific to Euphausia superba, or does the very fine filter apply to all species of the genus Euphausia? See e.g. (Weier 2005), p. 3, where they state that (in the sidebar) for E. pacifica. If so, I'd suggest "These filters can be very fine indeed in those species (such as Euphausia spp.) that feed primarily on phytoplankton, in particular on diatoms, which are unicellular algae)." What do you think?

only e.s has such an extreme fine net, m.n, is much coarser, and you can see the gut is red, from the crustaceans they prey on. Can you arrange the Hempel lit in the article, then I will ask Hempel to review and add stuff

Yes, I understood that M.n. has a coarser filter. What about E. pacifica? (See here for my source.) Lupo 07:07, 16 Jun 2005 (UTC)

I do not know, will ask arround Uwe Kils 13:38, Jun 16, 2005 (UTC)

[edit] Your work is appreciated

Just want to say that the work that has been done on the Krill and Antarctic Krill articles has been brilliant. These articles have come on enormously. I never Knew Krill existed until about a week ago and now i feel a hint of dare i say affection for the little critters (probably going a bit too far). Anyway well done to all who have contributed especially Kils and Lupo. Big up the Krill massive! Yakuzai 23:00, 15 Jun 2005 (UTC)

[edit] Taste?

How do krill taste? Like shrimp? I'm really curious! --Salleman 07:15, 17 Jun 2005 (UTC)

Google "+krill +taste" is your friend: Answers to miscellaneous questions on krill. To really experience it, you'd have to eat some krill, though :-) Lupo 08:19, 17 Jun 2005 (UTC)

I think they taste very good, they have a stronger taste than shrimp. We ate them raw, with the skin on, just with a few drops of lemon - the Norwegian paste is very good on bread - In New York city we found them dried, they are good on salad Uwe Kils 12:28, Jun 17, 2005 (UTC)

[edit] FAC stuff

Thanks for addressing my issues so quickly. Because I feel like I've already taken up too much space on FAC, I thought I'd write here instead. There are two remaining issues:

• I was thinking that an individual krill would make for a better picture at the top because many readers may want a mental image of these organisms from the very beginning. If a reader didn't know what krill looked like, the image currently at the top wouldn't help much. The best solution may be moving the swarming image to behavior and adding a new picture at the top. Obviously, it's still up to you, and I'll support the article either way.
  • Well, we have two good images of single krill: Northern krill and Antarctic krill. I didn't want to use the first, because it is already used at Euphausidae, too, and the second, because I wanted a clear distinction between the already featured article on Antarctic krill and this general article. So far my reasoning... I won't revert it if anybody inserts either picture, but if people really insist on an image of a single krill, I'd prefer an image of some other krill species. Lupo 16:55, July 12, 2005 (UTC)
• How does the footnote thing work? {mn|name for the computer|name in blue} for the link and then the same thing at the bottom with mnb instead of mn? I may even go back and change the references on Myxobolus cerebralis to match these.
  • That's pretty much it, except I used mnb2 at the bottom because I didn't like the cryptic sign to get back. I still can't figure out what it's supposed to be. So I settled for the symbolic name itself to provide the backlink. Lupo 16:55, July 12, 2005 (UTC)

Dave (talk) 16:02, July 12, 2005 (UTC)

That makes sense. If I can find a free picture of some other krill, I may add it. But You're probably right about reusing pictures. Thanks for the tip on the footnotes. Dave (talk) 17:10, July 12, 2005 (UTC)

• High-quality krill images other than those taken by Uwe are hard to find. I have e-mailed the photographer of these three images, asking him whether he'd release them under the terms of the GFDL. (These images were taken during a NOAA OceanExplorer expedition in 2002, but since I cannot find them on any NOAA web site, I must assume that he retains the copyright.) I hope he does; if so, I intend to use the stunning image of Thysanoessa longipes as the lead-in image. It might take a while until he answers, though; unless I'm mistaken, he's on another OceanExplorer cruise right now. Alternatively, there are these two images taken by one Dan Martin, a U.S. scientific diver who participated in a U.S. research programme at Palmer Station, but again I have been unable to ascertain the copyright status of these images. Lupo 15:16, July 13, 2005 (UTC)

  (Update 11:23, August 15, 2005 (UTC)) Dr. Hopcroft has indeed replied and agreed to license the three images of Thysanoessa spp. under the GFDL, and has even sent me a "bonus" image of the gills of a krill! Thanks very much to Fairbanks! Lupo 11:23, August 15, 2005 (UTC)

• • You're a credit to Wikipedia. Thanks for your hard work. Dave (talk) 13:51, July 14, 2005 (UTC)

• • (Edit conflict) I have replaced the lead-in image by another image of a Northern krill. I had asked for a GFDL release, and the photographer has agreed. Lupo 13:54, July 14, 2005 (UTC)
    • BTW, I have placed the swarm image in the "Distribution" section instead of in the "Behaviour" section because I didn't want two images of different sizes there, and I didn't want to make it too small either. Lupo 13:59, July 14, 2005 (UTC)

I thought this bit from the FAC discussion would be better here now, since the article has been promoted. And by the way, congrats on that and another great article.

• Oh and now that I'm curious, do you have any more info on the mechanism of bioluminescence Krill have? - Taxman ^Talk 12:18, July 15, 2005 (UTC)

• Hmmm. No, I don't, and neither does Wikipedia: Bioluminescence is silent on the issue of the precise mechanism(s). However, from one of the extlks of that article I found this page, which explains it all. How authoritative that website is, I do not know. I have never seen the term "euphausiid shrimp" for "krill" before... Lupo 15:19, July 15, 2005 (UTC)

• Actually, [[Bioluminescence doesn't cover it, but Luciferin does. It says the same thing your link does, that "euphesiid shrimp" use Dinoflagellate luciferin. It appears to have used the same link you found as it's source. The UCSB site isn't as good as a journal paper or something, but is a very reputable institution, so I don't think it's too bad a source. I guess this article could use a couple sentances expanding on the Luciferin and luciferase mechanism, and noting the specific type of luciferin if "euphesiid shrimp" really does mean krill or another source can confirm that. This one confirms krill uses that form of luciferin, but again, it is not a peer reviewed source. If someone has got the tools to research this more, that would be great, or if you want to go with what we have, adding a bit more on this would be great I think. - Taxman ^Talk 15:48, July 15, 2005 (UTC)

• Taxman, thanks a lot for this most intriguing question. As so often, you've found the (or a) weak spot of the article right away. I don't have the time right now to fix this (will do so next week); Googling for "+bioluminescence +euphausiid" turned up quite a few interesting sites, e.g. [1], [2], or also [3], which has some minor stuff on the life cycle phases, too. I'll also keep looking for peer-reviewed publications... Searching for "photophores" might also yield useful results. Lupo 19:13, July 15, 2005 (UTC)

• Those are all great links. I don't know that we need to expand it too much more now in this article, though I am quite intruiged now. I've always found bioluminescence interesting, ever since I first saw foxfire on some rotting wood as a child. Seeing the small note in this article about the bioluminescence piqued my curiosity. Maybe the only thing we should expand now is a bit on there being 10 photophores, maybe more on the organ's structure and note the specific type of luciferin, if we can confirm it to be Dinoflagellate luciferin. A subpage of the UCSB page give this tidbit "A modified form of this luciferin is also found in herbivorous euphausiid shrimp, perhaps indicating a dietary link for the acquisition of luciferin." which is also interesting. I should also be more careful and go back and cite my additions, but I'll await what else you can find. - Taxman ^Talk 19:54, July 15, 2005 (UTC)

• Great bioluminescence section. I've slightly expanded and referenced it. Lupo 11:15, July 18, 2005 (UTC)

[edit] Keystone?

Can someone explain why krill are considered a keystone species. They are clearly the most important species in the ecosystem, but that is not realy what makes a keystone. That is more a foundation species. A species is usually considered a keystone if its impact on the ecosystem is disproportionate to its abundance. Given that krill are possibly the most successful species on earth, it's hard to imagine their impact being disproportionately large relative to their biomass. Jmeppley 08:15, 30 March 2006 (UTC)

Krill is not a primary producer. Why would it be a foundation species, then? However, I think keystone species is right. First, that article itself says "The defninition [sic] given here is somewhat qualitative in nature because there is not yet an accepted, rigourous definition." Second, this article gives an explanation. I must admit, though, that I do not know whether that would be true globally or be applicable basically only to the Antarctic krill... maybe ask User:Kils, if you can locate him; he doesn't seem to edit much anymore. Lupo 08:57, 30 March 2006 (UTC)

Good point about not being a primary producer, so foundation species is not appropriate here. However on a different technicality, krill are not a species, they are an order, so I don't see how they can be a keystone species.

although beyond technicalities, this artcile says

They are considered a keystone species near the bottom of the 
food chain because they feed on phytoplankton and zooplankton, 
converting these into a form suitable for many larger animals 
for whom krill makes up the largest part of their diet.

To me this explains why they are important to the ecosystem, but I don't see how it satisfies the idea of dissporportionate importance and impact.

I did a brief literature search last night and found many articles refer to krill as keystone species without any reference and then move one. The ones that do offer support talk only about the Antarctic Ecosystem. Even then the idea seems to be that they convert all the plankton into a form that larger predators can use. While this is critical, because of their enormous abundance, it is not disproportionate. In a follow up on a 1994 meeting on keystone species, Robert Paine, who originated the concept in 1969, says:

The concept's potential significance to conser- 
vation biologists is that it designates species that exert 
influences on the associated assemblage, often including 
numerous indirect effects, out of proportion to the key- 
stone's abundance or biomass. 

Jmeppley 17:10, 30 March 2006 (UTC)