I study biology in France and experiment on water filtration with plants. I found that some chlorophyll-containing micro-organisms (about 10 micrometers in length) were raised in my basin.

I can't decide if this is a eukaryote (it looks like there are cellular compartments) or a prokaryote (it's very small!). I thought it could also be a cyanobacterium, that combines features of both prokaryotes and eukaryotes. Any ideas what this is?


I can't decide if it's a eukaryote or a prokaryote.

Well, that's certainly an eukaryote. We can clearly see the nuclei in the cells of your fist picture, as well as in the cells of your second one (not so clearly, though):

enter image description here

In the image above, the arrow starts right on one of the nucleus of that group of (apparently) three cells.

Besides that, despite some cyanobacteria being very long, 10µm is a lot for a prokaryote. The mean size of cyanobacteria is way less than that.

By the way, this:

... a prokaryote or a cyanobacteria (that can combine both characteristics)

Doesn't make much sense, because cyanobacteria are prokaryotes. More precisely, they are Eubacteria prokaryotes.

Finally, what eukaryoyte is this? I can't tell. It's most probably a kind of Chlorophyta, but I'm not able to go to the Class level. If you're interested in identifying it, you can try a taxonomic key. This one is for British freshwater algal flora, I don't know how different French algae are from the british ones: The Freshwater Algal Flora of the British Isles: An Identification Guide to Freshwater and Terrestrial Algae.

If I'd guess (and this is a wild guess), I'd say that this is a Chlorellales, as the famous Chlorella:

enter image description here

Also, have in mind that saying "that's an alga" doesn't help as well: worse than paraphyletic, algae is a polyphyletic group and, in biology, polyphyletic groups mean almost nothing.


Have you considered that it might be algae? (I think it is.)

enter image description here

There are many kinds of algae. I couldn't tell you which one yours is.

Algae Under Microscope


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.