Help identify this glass Krill of Panama

Feb 12, 2023 • 5:23 AM UTC

Bocas del Toro District, Bocas del Toro Province, Panama

140x Magnification

Microorganisms

Manu Prakash

I am a faculty at Stanford and run the Prakash Lab at Department of Bioengineering at Stanford University. Foldscope community is at the heart of our Frugal Science movement - and I can not tell you how proud I am of this community and grassroots movement. Find our work here: http://prakashlab.stanford.edu

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If I was to tell you that there is this little crustacean – when they group together, you could see them from space. Or, if I told you, only one species of these crustaceans can weigh 400,000,000 tonnes. That is more than the entire biomass of humans on this planet. You might think I am joking; but if you see this video – I think you will start believing me a little.

I was in Panama a couple of months ago, and while on a late evening Kayak (which was a terrible experience because of the sand flies – see my previous post: https://microcosmos.foldscope.com/?p=1958). But the reason I endured hundreds of sand flies eating me alive (with some risk of getting leshiminasis); was because of these tiny shrimp. Tiny tiny shrimp.. On my kayak – I could see a small swarm of them. I had never seen swarming behavior by a millimeter scale crustacean – and j was very intrigued.
So on the kayak; I tried to catch them by putting the water bottle in the water. I tried almost 50 times and every time; they were fast enough to swim away. Finally I was able to catch two; and could see the huge eyes. Take a look at one of them – below on a glass slide.

Look at that kick; it’s so fast – it’s barely visible. So, it was obvious that I was going to foldscope the krill. My fascination grew when I noticed that the krill was almost absolutely transparent.
Here are a few videos. Watch till the end (I know it’s a long video ~7min ; you will see an incredibly strange behavior of head banging.

I took several other videos; see below.

You can watch the appendages moving so fast; you actually don’t see them.

I find so many fascinating structures in these short videos. The incredible 369deg eye structures – filled with a pigment that allows for individual micro lenses be isolated from one another. Surprisingly, this is the only structure that has any pigments.
I also find the whole idea of complete transparency for a swarm quiet intriguing. Being in a swarm makes them quiet visible; but individually they are transparent. Here are some foldscope and macro shots of the same.