Polarized Explorations Part 3!! Copepods and Ciliates

Mitali | Thu, May 31, 2018, 12:07 PM

Hello everyone!

Thanks to iGEM I’ve had absolutely no time for foldscoping lately 🙁 but I’m determined to exploit this mini vacation in Ratngiri to its fullest 😀

Till now I’ve observed some pure chemicals and fruits in cross polars but this time I’ve tried doing something that I’ve been dying to try my hands on and that is imaging live samples in polarization!

While observing this water sample I remembered that When I observed recrystallization through crosspolars I noticed that compounds in melted form do not show birefringence..only the crystal forms do…That’s when I started to wonder, would ciliates show birefringence at all?

Even if they do posses any optically active compounds in them they wouldnt be in crystal form…I had no hopes from ciliates

IMG_20180524_115706 — Location from where I collected the water…Can you spot the shoal of fishes in there?

IMG_20180524_115712 — And the cute turtle? There were 2 such turtles in there 😀 sadly one went inside the pond while I tried to click.

So here are our ciliates!

I thought if not ciliates let’s see wether atleast the Pediastrum shows birefringence and Voila!!

What I observed was just the opposite of what I expected!! A ciliate showing birefringence!! How??? Did it engulf particles of mud that showed birefringence?? What could the reason be??

Here are some pictures of the beautiful Pediastrums

The next thing in the sample that caught my attention were copepods!

Copepods are planktons found ubiquitously in fresh and sea water. They have a mineralized chitin containing exoskeleton. Would that account for some action in cross polars?The thought of a copepod showing birefringence excited me !!

I thought, let’s try and see!!

And then began the chase…

Copepods swim irritatingly fast!! I spent hours trying to catch them with my tiny dropper and finally got hold of these devils

So here is our beautiful copepod with 2 egg sacs