Watching individual bacteria in a 300 year old pond

Sometimes; wonder awaits you in seemingly quiet places. Walking up to a 300 year old pond that is fed by a stream under water is one such quiet place. But a lot is happening in this ecosystem that’s right below the surface. A quick drop of water fro here into my foldscope – and you would be convinced what an incredible microscopic rain forest we have right under our feet.

I will write a detailed post soon – but let’s see how many different bacteria and ciliates can you identify in these few videos (comment section below). Look out for the helical cork screw swimmer.

For techniques, I am just using a table lamp as my light source and a standard Foldscope (out of a BCK kit). As I angle the foldscope with respect to the table lamp; I can generate various contrast mechanisms. For more details on this angular illumination – also see my old post at

Here is a quick video of the setup itself.

Join us in this wonderful journey of the microscopic world. What will you discover?



5 Comments Add yours

  1. laksiyer says:

    Oh my goodness. The variety of bacteria is astounding!! I wonder if those long bacteria are Beggiatoa? That cluster of ciliates have a most unusual asymmetry. Manu, how did you make your slide, with a glass coverslip?

  2. Manu Prakash says:

    Indeed @Laks. The bacterial diversity is incredible. And this is only “one” drop of the water. Ecological diversity at microscopic scales is indeed mind boggling.. to say the least.

    I see a filamentous bacteria; and I also see them dividing. The long filaments with a pinch point seems to be dividing cells; which are the most abundant. They have a unique swimming mode. Also; a beautiful (slightly rare) helix like cell swims forward and backward all the time (its like a cork screw). Do you know of a simple app on phones to mark and annotate videos.. that would be very help to label features. I know we can do this with a video editing software; but want a simpler tool.

    Also; for making slides – all I do is just a regular slide and a regular cover slip. I just attach two tapes as a way for the slide to not crush the organisms. That’s roughly 100um of spacing. After that I put on my slide and again just tape the edges (I tape the edges with regular tape so as for the cover slip to not fall off and also for the slide to not get “caught” in the foldscope slit where the slide is inserted.

    I can show this when you are here in our neighborhood. I am so excited to host you here.


  3. GujuRocks says:

    Hey i took a slide from a watersource near me in mumbai
    And i cant see any bacterias
    I can see some debris and algae
    Is that due to low mag lens
    Or is that water too clean . Where can i buy a high mag lens

  4. Manu Prakash says:

    GUJURocks, all the data shown above is taken with the same lens you have (140x). Different sample will have different concentration of bacteria (and other organisms).


    1. GujuRocks says:

      Thanks for the reply
      I got it. I actuall took a sample from water tank of street workers.
      that actually did contained dust and debris but nkt organisms .
      I took a samples from sea at shivaji park . it had organisms .
      I’ll be posting later.

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