Is this trachelomonas?

nanometer · Post by **nanometer** » Mon May 16, 2016 7:14 pm

This one has been stumping me. It looks like it's a trachelomonas, but the combination of fine spicules and coarse 'spicules?' don't seem to show up on any photos I can find of this. Body about 18 um.

much appreciated.

René · Post by **René** » Mon May 16, 2016 10:55 pm

Hello nanometer, why do you think it is Trachelomonas?

Best wishes, René

nanometer · Post by **nanometer** » Tue May 17, 2016 5:34 am

It's something that would seem to have many of the elements I see here--single flagellum, thick and thin spines. I admit it's not a great fit, but I don't know what it is.

carlos.uruguay · Post by **carlos.uruguay** » Tue May 17, 2016 12:45 pm

They do not seem Trachelomonas

nanometer · Post by **nanometer** » Tue May 17, 2016 3:30 pm

OK-- I'm back at square one on this one. Thanks

carlos.uruguay · Post by **carlos.uruguay** » Tue May 17, 2016 5:34 pm

Have you brightfield images?

nanometer · Post by **nanometer** » Tue May 17, 2016 6:05 pm

No, and this is the only one I have ever seen. Good idea though when I see something I don't recognize to try to get various lighting.

Bruce Taylor · Post by **Bruce Taylor** » Tue May 17, 2016 6:05 pm

I'm not much good at identifying flagellates, but (given the disparate flagella and spines) perhaps the chrysophyte Paraphysomonas vestita?

And another, from Won Je Lee (Free-living Heterotrophic Stramenopile Flagellates from Gippsland Basin, 2007):

But yours is less round, and seems to have thicker scales/spines mixed in with the fine ones...

Well, I'm out of ideas.

carlos.uruguay · Post by **carlos.uruguay** » Tue May 17, 2016 8:12 pm

Phase contrast sometimes with very thick samples does not give a clear idea

Ecki · Post by **Ecki** » Wed May 18, 2016 12:13 am

This is a indeed a Paraphysomonas cell. Paraphysomonas is a colorless amoeboflaggelate with pin-shaped silicious scales and two cilia of unequal length. The morphological traits to differentiate between species is the cell size and the scale details, the latter only visible for an electron microscope. Nearly all water bodies are abundant in these amoeboflaggelates. There are approximately 50 species described but there are many many more.

Here are electron microscopic images: http://penard.de/Stramenopiles/Chrysophyceae/

If you want to dig deeper, there is a paper from Scoble and Cavalier-Smith 2014 with a revision of the genus.

Best regards,
Ecki

nanometer · Post by **nanometer** » Wed May 18, 2016 6:08 am

Thanks Bruce and Ecki. I will try to track down the paper, because no image in any of my books shows the few thick spines seen in the photo, but everything else seems to fit. The electron photos are amazing--but no thick spines--unless they are actually pseudopodia.

Thanks again. Now I can put them in a proper folder with a name!

Steve