Microscopic algae render my fascination every time I have  the chance to observe them .  Instantly,  I feel the need to pause for a while and to regard  admiringly not only their capability to transform inorganic matter (carbon dioxide, mostly) into organic molecules (glucose, for instance) and their active production of oxigen, but also their exquisite beauty.

            After viewing the previous image, you probably might have recognised two specimens that have been shown for several times on microcosmos.foldscope, that is, Spirogyra spp and a diatom species. The third one, the one on top, is Closterium spp.  Watch this  graceful trio  in the broken silence of their supportive environment.

Genus Closterium includes species that resemble rods or crescents. It is a desmid, I mean, a single celled green algae living in fresh water whose name is related to the fact that it is made of two halves being mirror images of one another. Therefore, it is symmetrical. This symmetry leads to  beautiful shapes and make every desmid aesthetically so appealing that I would like to  invite you, if you  have the chance to find them (they are worldwide), to make posts so that we can share the variety of genus and their artistic elegance.

Where the two halves  join, the cell usually narrows (not in our specimen). This is exactly where the nucleus is located. Normally two chloroplasts project from this point and provide a marvelous green color to our eyes. Starch is synthesized in them, specifically in the dark patches seen next:


             Closterium has also one curious feature: one vacuole (organelles containing different substances -water, pigments etc. – ) on each end of the cell. They are patent in the next video, where you can  also see this algae moving as if it were sliding gracefully (locomotion is caused by secretion of mucilage from pores in the cell wall).

           They live in clear waters. This is where I found them:



     Another unicellular algae I have recently had the opportunity to foldscope is Phacus spp. It is not a desmid but an euglenoid. It exhibits certain features I would like to share with you. Firstly, its shape: it looks like a delicate leaf, moving  softly in fresh water.

      Secondly, its eye spot, a red dot it uses for light detection. Watch the following video, please (I zoomed in):

Here is a drawing to figure it better:


    Paramylon bodies contain a substance similar to starch, but its chemical structure is slightly different (as a biologist, it is an amazing feature).

         All in all, these are only two examples of unicellular algae:  a sand grain in a vast desert. Therefore,  let us unveil its  splendor using our foldscopes!

Cristina Bosch


5 Comments Add yours

  1. Janice says:

    Hi Cristina,

    A wonderful post! I think the diatom is a Navicula tripunctata–not sure about the species, but just a hunch. Can you collect some more diatoms and show them to us using your foldscope? You can make some semi-permanent slide mounts using corn syrup, which has a high enough refractive index for viewing diatoms. I am curious to know if the diatoms you have seen are epiphytes.


  2. laksiyer says:

    What a wonderful post Cristina. Really enjoyed reading about Closterium. Thats a vacuole!! Didnt know it. I’d love to look around for more such algae,. Their diversity of shapes and locomotion types is fascinating. Currently, am trying to see if I can culture a few of them in minimal salt solutions and artificial light. Success has been slow. If you have tried this and have any ideas, please let us know.

  3. Manu Prakash says:

    What an incredible post @Cristina. Lovely set of geometries to think about – and the carbon fixing organelles – that’s beautiful. I had only heard about them; I was not sure they are so readily visible.

    @Janice: Love the corn syrup suggestion. Will try it soon.


  4. Janice says:


    A website page that is worth looking at: http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artjan03/wdmount3.html

    Besides corn syrup, lots of mountants are suggested for slide preparation. The Mic-UK website has lots and lots of information that would be helpful to all foldscope users!


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