Strange set of "threads" radiating from this organism

[macnmotion]

Curious about this organism. Sorry for the quality of the photo but this was very small and faint. Shot with 40x objective, if you open up the image to 100% you will see what appears to be a series of symmetrical threads radiating from the organism -- they appear black in this phase contrast image. Does anyone have an explanation of what this is?

organism with many flagella sm.jpg (68.12 KiB) Viewed 908 times

[WWWW]

Heliozoan ?

[macnmotion]

Heliozoan ?

That definitly seems plausible, thanks.

[Bruce Taylor]

The word "heliozoan" is no longer helpful, unfortunately. Organisms traditionally regarded as "Heliozoa" are now scattered all over the eukaryote tree of life. Actinophryids are in the Stramenopiles supergroup, "heliozoans" that have scales and spicules are in Centrohelida or Centroplasthelida, Nuclearia is in Opisthokonta (with you and me!), Clathrulina and other desmothoracids are in Cercozoa, etc. In certain classification schemes proposed by the late Thomas Cavalier-Smith, "Heliozoa" is retained as a formal taxon, but it is a very restricted group (essentially a synonym of Centroplasthelida). These days, "heliozoa" is just an informal term for "critter that looks kind of like a sun."

The organism we see here, has radial filopodia (i.e. filose pseudopods) with distinct granules (extrusomes). So, it likely falls in the cercozoan group Granofilosea. It looks somewhat like Massisteria (a mainly marine creature), or Microcometes (a freshwater organism), but I am not equipped to identify it to genus.

[macnmotion]

The word "heliozoan" is no longer helpful, unfortunately. Organisms traditionally regarded as "Heliozoa" are now scattered all over the eukaryote tree of life. Actinophryids are in the Stramenopiles supergroup, "heliozoans" that have scales and spicules are in Centrohelida or Centroplasthelida, Nuclearia is in Opisthokonta (with you and me!), Clathrulina and other desmothoracids are in Cercozoa, etc. In certain classification schemes proposed by the late Thomas Cavalier-Smith, "Heliozoa" is retained as a formal taxon, but it is a very restricted group (essentially a synonym of Centroplasthelida). These days, "heliozoa" is just an informal term for "critter that looks kind of like a sun."

The organism we see here, has radial filopodia (i.e. filose pseudopods) with distinct granules (extrusomes). So, it likely falls in the cercozoan group Granofilosea. It looks somewhat like Massisteria (a mainly marine creature), or Microcometes (a freshwater organism), but I am not equipped to identify it to genus.

I can't begin to describe the smile on my face as I read your detailed description. Thanks!

[Bruce Taylor]

Another possibility within Granofilosea would be Heliomorpha (=Dimorpha). And outside Granofilosea, there is also Ciliophrys, a flagellate stramenopile with granular axopodia. That one should have a flagellum, I think, but it might be concealed in this image.