MicrobeHunter.com Microscopy Forum

Hello ,

I have a question about the protozoa Peranema sp.... as i've just observed it for a few hours this afternoon changing forme like an amoeba and emitting pseudopodia !! First i was filming and observing what i thought was a tiny amoeba and then I thought she had just the misfortune to have met a paranema and been absorbed.
And then 30 min laters I saw another peranema wandering around with its long flagella and stopped to turn into a amoeba form with several pseudopodia !!

I have it in video and i'll post it on youtube ( my connection if very slow so it might take some time tonight) .

I read that it was considered an " Peranema is a genus of free-living phagotrophic euglenids" (from wikipedia ; i know its not a very realiable source but still..)

Could anyone tell me please ?

thanks

chris

here are the 2 videos i posted..

https://www.youtube.com/watch?v=8rIlTmvWbkI


https://www.youtube.com/watch?v=0hRdkbpWlbw

.
Wonder if what you have there is Hyperamoeba flagellata.

See link: https://www.researchgate.net/publicatio ... _apparatus

woaw !! thank a lot for the link !! indeed it could be ; I dont know much about protozoa but they are so amazing and beautifull!!

thanks

This is not Peranema, which is indeed a heterotrophic euglenid, as the Wikipedia article says. As it happens, I wrote that article for Wikipedia about ten years ago. It probably does have an error or two, and I should revise it, one of these days (I should add a passage about the closely related genus Jenningsia, which is easily mistaken for Peranema.

Hyperamoeba is no longer considered a valid genus. All of its previous species have been moved to various genera in Myxogastria (=Myxomycetes). It turns out, they are all slime moulds! As you may know, slime moulds live as single-celled amoeboids for much much of their life cycle, but can also aggregate to form large multicellular organisms. Species previously placed in Hyperamoeba have found new homes in slime mould taxa such as Stemonitis and Physarum. "Hypermoeba flagellata" now goes by the name Physarum flagellatum.

see: https://onlinelibrary.wiley.com/doi/epd ... 09.00466.x

Your creature is certainly a flagellate amoeba. Amoebae with flagella occur in a variety of groups. It is certainly possible that the one you recorded is a free-living single-celled myxomcyete (i.e. the amoeboid phase of a slime mould).

Bruce Taylor wrote: ↑

Thu Apr 22, 2021 12:59 am

Your creature is certainly a flagellate amoeba. Amoebae with flagella occur in a variety of groups. It is certainly possible that the one you recorded is a free-living single-celled myxomcyete (i.e. the amoeboid phase of a slime mould).

Wait, what? An Ameoba can be a slime mould?

Geez man, there is so much to learn about these things.

I think this might be a representative of Peranema (or the closely related genus that Bruce mentioned):



Definitely an heterotrophic euglenoid. Hard to tell from the B&W video but there were no chloroplasts; plenty of what appear to be starch grains though.

Red_Green wrote: ↑

Thu Apr 22, 2021 2:44 am

Wait, what? An Ameoba can be a slime mould?

Yup, the "slime moulds" we commonly encounter on fallen logs and leaves have a phase of life in which they live as single-celled amoebae, and most are currently placed in Amoebozoa. That includes the widely studied species Dictyostelium discoideum, and the celebrity organism Physaryum polycephalum, recently hyped by the Paris Zoo as "The Blob": https://www.wired.com/story/all-hail-th ... g-science/ Not all "slime moulds" are in Amoebozoa, though...the term is very loose, and just refers to a life cycle where single-celled organisms get together to form fungus-like fruiting bodies. That way of life has been reinvented numerous times, in a wide variety of groups. There are bacteria that form sporangia (the myxobacteria), and there is even a group of ciliates that do this (Sorogena)!

As for the critter in the OP, while it could be a myxogastrian or "social amoeba" of some kind, my first suspicion is that this is a species of Mastigamoeba: https://www.arcella.nl/mastigamoeba/

jmp wrote: ↑

Thu Apr 22, 2021 3:16 am

I think this might be a representative of Peranema

Yes, your video does show a euglenid in the family Peranemidae (either Peranema or Jenningsia. These guys have very malleable bodies (thanks to a specialized skin or "pellicle" made up of protein strips that slide against one another). However, they do not form pseudopods, so are not "amoebae" in any sense.

By contrast, the organism in the OP does form pseudopods, and meets anybody's definition of an "amoeba". Possibly Mastigamoeba, as I suggest above (but I am not great at identifying amoebae, so take that with a grain of salt)

Thanks Bruce. The motion of the euglenids is quite distinctive, that pellicle really imparts flexibility to this organisms; they are truly contortionists. I noticed that the movements of the organism in the OP's video were different, somehow less fluid, and clearly showed pseudopodia. Yet, its behavior reminded me of the behavior of the euglenid from my video and considered this interesting enough to have it here for comparison.

I was sorting out my videos on my PC this morning (sunny morning in Paris) and I found out that I had filmed an amoeba and didnt noticed its long flagella !! So i think i filmed this specimen already..

Here's the video.. its been filmed with a B&W astro camera (ZWO ASI 120M) so the quality isnt very high as i didnt know how to set it properly but still this time the amiboid form is obvious with several real pseudopodia and its long flagella !!

https://youtu.be/3Wnq1dtGJ38