Talk:Foraminifera
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Foraminifera found on the top centimetre of sediment at Challenger Deep, 10,896m below the surface. [1] One diffrence is these foraminifera have a soft shell, unlike those found in shallow depth which has hard shell.
Organic-walled forams can be found at shallow depths as well. The people who study forams were excited about the Challenger Deep discovery because their study organisms now have the distinction of being some of the deepest-dwelling creatures!
Safay 20:02, 17 October 2005 (UTC)
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[edit] Their role in the formation of sand
Could someone please explain how these forams contribute to the formation of sand? Some information on the subject can be found at http://www.susanscott.net/Oceanwatch2002/mar1-02.html
Thanks for the Susan Scott article link.
In tropical places where there is not a lot of input of terrestrial material, the white sand is made of calcium carbonate. That calcium carbonate comes from broken up coral, broken shells of molluscs, echinoderms, and othermarine animals, calcareous algae like Halimeda, and the tests of foraminifera. The tests of foraminifera sometimes makes up a significant proportion of the sand. In Kudaka Island in Japan, the sand on the backreef is almost entirely made up of foram tests. So these tiny creatures, which live on the reef or on the surface of the sand, die and leave behind their tests.
Foraminifera have been refered to as "Living Sands" by John J. Lee, in my estimation the greatest living contributor to foram biology. If you have access to academic journals, he has written an excellent general introduction to endosymbiont-bearing forams: John J. Lee, 1995. Living Sands. BioScience 45(4):252-60.
Safay 20:02, 17 October 2005 (UTC)
[edit] Not all forams are marine
Not all modern forams are marine, although all planktic ones (and all testate benthics) are. Modern molecular work groups numerous 'naked' non-testate benthic forms inside the foraminiferal clade, some of which are freshwater.Badgerpatrol 04:32, 10 January 2006 (UTC)
Can you provide a reference? Various non-testate amoebae used to be considered forams, but last I heard molecular work only supported the inclusion of Reticulomyxa, and that was only two or three years ago. Josh
Hi Josh- The ones I was particularly thinking of were Nature 399, 27, 1999 'Naked foraminiferans revealed', Pawlowski et al., and 'The evolution of early Foraminifera', Pawlowski et al., PNAS, 2003, 100, 20, 11494-11498 (full text here), but a quick glance at the web also reveals Pawlowski et al. 'Molecular evidence that Reticulomyxa filosa is a freshwater naked foraminifer' J Eukaryot Microbiol. 1999, 46(6):612-7. (abstract here), 'Molecular phylogeny of Foraminifera a review' Pawlowski and Holzmann European Journal of Protistology, 38, 1,2002,1-10 (abstract) and especially 'Freshwater Foraminiferans Revealed by Analysis of Environmental DNA Samples' The Journal of Eukaryotic Microbiology, 50, 2, 135-139 (abstract). Although all of these come from the same research group (largely because few others are working in this area, I think), the evidence for placement of FW protists within the foram clade seems now to be quite strong. I must stress that my knowledge of benthic forams is very scant and it is very likely that you will have a greater familiarity with the literature! Cheers, Badgerpatrol 00:06, 11 January 2006 (UTC)
- I didn't realize Reticulomyxa was freshwater or know about the environmental samples, but I should have remembered some of the simple-shell forams are, given that I mentioned such another page. Thanks. Josh
Note here that there is a disjunct between the systematics and phylogenetics - the evidence so far says that the reticulomyxa nest within the (clade including all) foraminifera, but I don't think there has been a revision to the taxonomy. I think everyone is waiting for more data to come in before shaking up the taxonomy - the papers you cite above, as far as I remember, only include sequence data from a single locus. I'd say that more loci need to be sequenced and more exemplars need to be included in the analysis before anyone is ready to "definitively" revise the taxonomy. Safay 06:09, 19 January 2006 (UTC)
On a similar note, my understanding was that planktic forams, unlike benthics, were (I think...) exclusively sexually reproductive?Badgerpatrol 00:11, 11 January 2006 (UTC)
[edit] Plain English
I think this article is a bit to technical for the neophyte. I would love to see it broken down a bit more into plain English, for the rest of us! —The preceding unsigned comment was added by EveRickert (talk • contribs) .
[edit] Cite references
I noticed you don't have a reference for the number of extinct or fossil forams.
I don't know how to add references (yet), and haven't taken the time (yet) to track down the original article, but I ran across this website: http://web.archive.org/web/19990203140657/gly.fsu.edu/tour/article_7.html
"Evolution at Sea - a Complete Fossil Record from the Ocean Upholds Darwin's Gradualism Theories" adapted from an article that first appeared in Research in Review, published by Florida State University, on-line article revised Oct. 1997
and it has this statement in it:
About 330 species of living and extinct planktonic forams have been classified so far. After thorough examinations of marine sediments collected from around the world, micropaleontologists now suspect these are just about all the free-floating forams that ever existed.
They have also classified them and tracked their evolution for over 500,000 years with a virtually complete record of the transistions. Good reading.
This may be an online version of the original article: http://web.archive.org/web/19990504095208/www.gly.fsu.edu/tour/article_3.html
It has much the same information and an earlier date (1995)
paul 12:49, 10 December 2006 (UTC)
- There are a lot more than 330 (planktonic species- there are many thousands of recognised species overall, if benthics are included also), but the exact number depends largely on personal opinion. Different workers synonymise species as they see fit; given recent work, it's probable that there are actually (i.e. phylogenetically defined) at least several thousand planktonic species (although it may not be possible to recognise all or even most of these). Off the top of my head, I'd suggest that there are maybe 2-3 thousand described species, most of which are obviously synonymous. Loeblich and Tappan may give an exact estimate of actual planktonic diversity in one of their papers. I doubt if that particular journal is peer-reviewed (sounds like a faculty newsletter or similar) but if it is then why not put it in as a placemarker for now, if the actual printed paper can be located. Badgerpatrol 15:33, 11 December 2006 (UTC)
