The Twilight Zone of Testate Amoebae
This is an area to post interesting/intriguing/unknown things about testate amoebae or about the society.
Outstanding Mysteries
22/11/2011- Mystery microfossil, identification requested by Richard Payne.
Hi folks, I was wondering if anyone could help identify these beasts. They are from a peatland mesocosm experiment and are very numerous. They are about 30-50 microns diameter and appear to be made of primarily organic xenosomes. In some (eg. pic 6) there appears to be an irregular-shaped aperture occupying much of a side. My first instinct was maybe Phryganella acropodia but these look odd to me. Firstly in some of them it is really hard to see any aperture at all (but these are in a plankton chamber so it's not easy to turn them over without sending everything flying). Secondly, some of them seem to have a weird sort of 'halo' rather than a clear edge to the test which looks a bit weird. What do you think? any ideas? I've already asked a few people and the general opinion has been 'maybe P. acropodia'.
Solved Mysteries
3/14/2011 - Nebela from British Columbia (Canada), identification requested by Edward Mitchell
This amoeba was described as a new species: Nebela meisterfeldi n. sp. Heger et Mitchell, in honor of Dr. Ralf Meisterfeld, one of the most distinguished researchers in testate amoebae systematic and ecology in recognition for his contribution to this field.
See literature section: Kosakyan A, Heger TJ, Leander BS, Todorov M, Mitchell EAD, Lara E. 2012. COI Barcoding of Nebelid Testate Amoebae (Amoebozoa: Arcellinida): Extensive Cryptic Diversity and Redefinition of Family Hyalospheniidae Schultze. Protist 163(3): 415-434. doi: 10.1016/j.protis.2011.10.003
Thierry Heger found this Nebela species in British Columbia (Canada). We believe it is a new species as it does not match any described species we know.
If you have any suggestion, we can discuss about it in the Forum!
12/13/2010 - Beast from Serra do Japi, identification requested by Dan Lahr, mystery solved by Yuri Mazei
UPDATE Yuri Mazei has identified this amoeba as Difflugia nodosa. Taxon was originally described by Leidy as Difflugia pyriformis var. nodosa, and raised to species status by Ogden and Zivcovic 1983. You can check out page 355 of the Ogden and Zivcovic reference for SEMs of this beast which is freely available at BHL here!
Original request - I found about 8 of these amoebae some years ago in the beautiful Serra do Japi, located in my hometown Jundiaí. The Serra is one of the last remaining Atlantic Rainforest reserves. There is quite a deal of controversy whether it is primary or not.
In any case, I found this thing and did not know what to make of it. I originally thought it looked like a Pontigulasia, but the v-shape in the neck was not very clear. Then I thought it looked somewhat like the Difflugia pyriformis or Difflugia compressa portrayed by Leidy. Then when I went to the SEM and saw the cement (which seems Lesquereusia-like), I didn't know what to make of it.
I apologize for lack of scale bars, but the notebook with the information is somewhere back in Brazil. If I remember correctly, the test was big, something in the 300 micron range, perhaps more. I can't remember the type of habitat either, but it could've been puddles filled with decomposing leaves…
If you'd like to help me out with identifying this beast, we can discuss about it in the Forum!
