Help identify this glass Krill of Panama 

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: 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. 

Here are some macro shots. 

 If anyone knows this exact species; I would be delighted to know. 



Ps: here is a picture of where I was – at Bocas Del Toro in Panama. 

Ps: now for some light hearted fun; here is another view of a life of krill. 

9 Comments Add yours

  1. Manu Prakash says:

    @Laks: special note for you – don’t miss the head banging behavior in the 7min video; which starts exactly at 4min or so. Any idea, what could be a function associated with head banging or the strange eye banging 🙂


  2. laksiyer says:

    @Manu, these are fascinating video and so many aspects of the crustacean anatomy are plainly visible. I remember your post on the transparent fish and now this krill. The eye movement is fascinating. I could be wrong, but I think it helps in flipping between stereo vision and panoramic vision. The krill appears to be lateral-eyed and depends mainly on panoramic vision and then the sudden move to stereo vision suggests that by flipping between these vision modes, the krill visualize each other and also estimate their inter-kin distance, and adjust their spatial position to be part of the swarm. Need to look up the species..

  3. Saad Bhamla says:

    @manu – what a beautiful series of videos!! the eyes are gigantic!

    in the first video, i think i saw what must be the gills – close to the upper gut – they are vibrating insanely fast!

  4. Manu says:

    @Laks; you are the first one to give me an explanation of the head banging. They form amazing swarm; so having two modes would be very valuable. Do you have any reference on this; or did you just think about it..

    @saad: Yes; you are right. I noticed something beating inside but did not think about gills. They are incredibly fast. At that time, I did not have my high speed phone; but the legs are basically a blur.

    What I find interesting about the leg motion is the fact that they never stop beating.. how strange is that. So to remain stationary; they need to swim 🙂


  5. laksiyer says:

    @Manu. This was just a hypothesis. Let me look it up. Lots of people have worked on stereo vision across animals, should find something.

  6. Manu Prakash says:

    Wow! I just realized something – looking back at my data again; I realized I might have imaged statocysts in the tail of this mysid. The two little circles in the tail were such a puzzle – and reading a book I stumbled on the same image.

    So happy when we make an observation and many years later, it makes sense. It’s a wonderful feeling – I will make a detailed note on the same soon. Just wanted to share a sense of joy 🙂


  7. laksiyer says:

    @Manu. Yes I see them now that you point it out..

    1. Manu Prakash says:

      Yes. It reminded me of a very important idea – “we can only see what our minds eyes allows us to see”.. this lesson will now stay with me forever. Time to look through old data as much as the new 🙂


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