Mysteries of Dal Lake, Kashmir – Part 1

Oct 16, 2019 • 6:51 AM UTC

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140x Magnification

Microorganisms

TCIS Outreach

We are a group of students, volunteers and staff working with TIFR Hyderabad's Science Education and Outreach program: http://www.tifrh.res.in/~outreach/

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It all started when my friend got a water sample from Dal Lake, Srinagar. The ecosystem of Dal is ecologically rich with 117 recorded species of hydrophytes and phytoplankton . Here are some views of this beautiful Lake: wonder what we can find inside it, under the Foldscope!

Dal Lake, Srinagar, Kashmir

In my first observation, I saw many microbes moving in so many different ways! I used maximum zoom on the iPad to view them under the Foldscope.

Look carefully at the centre of the field of view – the spiral motion is enthralling! This is perhaps a spiral bacterium. Isn’t it?
I found some prokaryotic filamentous cyanobacteria; they are bluish-green. In the second photo we can see an akinete on one of the filaments.

Cyanobacteria

Another type of cyanobacteria, Oscillatoria sp. , are capable of a wave-like motion. Notice the filaments oscillating back and forth.

We can see ‘separation discs’ (colourless or whitish) in the filaments.
There was a variety of prokaryotic and eukaryotic life in this sample and a treat to see under the Foldscope! Can you help me identify some?

I think the star shaped structure is a diatom called Actinastrum and the cylindrical-stacked structure is a desmid called Scenedesmus .

Observe the star-shaped and cylindrical-stacked green structures.

This rib-like structure is a perhaps a diatom too.

Is this a diatom?

From these spiral choloroplasts I deduced this one is Spirogyra sp . A dead rotifer seems to be floating around.

I was thrilled to see the ladder-like structure (one filament seems empty and the other is with a zygote). I believe this is the scalariform conjugation of Spirogyra . Can anyone help to verify this?

I also saw branched algae. I think this is Stigeoclonium sp.. Is it correct?
I found plant-like algae in the water sample. The image on the left is observed under the magnifying glass attached to the Foldscope light source. I think it is Chara sp .. The picture to the right is the detail of the leaf-like structure under the Foldscope. (I use concave slides to examine water samples!)

Plant-like algae – Could it be Chara ?

This is the leaf-like structure There were many structures or algae that I could not distinguish. They are so unique, different from any that I have seen before. What do you think they are?

Pearl-like structures? Are they eggs or a colony?

Are they eggs or a colony of algae? A few weeks ago, Purnati, a PhD student who is also one of our outreach volunteers, studied the Dal Lake sample using a confocal microscope at the TIFR Hyderabad imaging facility. She observed auto-fluorescent algae that were emitting in red when excited with 594 nm wavelength of light. The source of the auto-fluorescence is the chlorophyll of the algae .

The natural fluorescence of the algae can be observed as the confocal microscope scans through the different planes (height) of the water sample. The image on bottom left is the b/w image of Pediastrum sp. integrated over the Z axis of the colony.

The picture to the bottom right is a different species of Pediastrum.

Colony of alga as seen with a confocal microscope

Another species of algae as seen under the confocal microscope

An algal colony organises in the shape of a hollow sphere as it floats in water. Can you identify the species?

Rib-like structures suspected to be diatoms can be also seen under the confocal microscope.
It was encouraging and humbling to learn that the Foldscope can examine a drop of water quite comparably to state-of-art microscopes used for advanced scientific research!
See more about the fauna of Dal Lake in the next post – Part II 🙂
Cheers,
Ashalatha
– with Chandrika and Purnati