Mystery embryos in a jelly sack

At a fountain inside the UNCC campus in Addis Ababa (Ethiopia) – I found a floating jelly in the water. It was a big surprise to see for a simple reason – I have never seen an egg sack that feels like jelly that does not belong to a marine invertebrate. But here I was in a land locked city – how can a marine invertebrate deposit eggs in a fountain!

So I picked it up; and it was time to examine it under a foldscope.

The above is a 1/2hr time lapse with foldscope mounted on my iPhone. For time lapse, I use a software called lapseit.

I did a little more digging online, and found that caddiesfly lay eggs in a jelly like structure! So could this be eggs from a caddiesfly. So far that is the only rational explanation I have. Jelly can help reduce desiccation and also keep all the eggs together and might also have anti-bacterial properties. It’s a fascinating evolutionary arms race to keep your eggs safe for them to actually survive in the wild.

Keep exploring

Manu & Caroline (postdoc, University of Washington)

PS: please read the comments below – specially the fact that “chromonid” eggs can harbour and hence be a source of “Cholera”! Yes – you heard that right. See links below –

Here we show that egg masses of the non-biting midge Chironomus sp. (Diptera) harbour V. cholerae and act as its sole carbon source, thereby providing a possible natural reservoir for the cholera bacterium.

Now I wish I was handling the egg sack with more care!

11 Comments Add yours

  1. Manu Prakash says:

    Here is a reference for caddiesfly larvae:
    https://www.jstor.org/stable/10.3138/j.ctt130jwx3

    More to follow up soon on this thread!

    Cheers
    Manu

  2. I was curious and did a little digging, I found strong contender for your case here, they could be Chironomid (non-biting midges) egg masses as well.
    https://www.google.com/search?q=chironomid+eggs

    Here are some interesting articles w.r.t bacteria and the egg masses. Spoiler( no antibacterial property there) 🙁
    https://www.nature.com/articles/35083691
    https://jeb.biologists.org/content/211/22/3536

    Strangely they’re related(non phylogeny) to Tardigrades too.. 😉

    Cheerios
    Yash

  3. Manu Prakash says:

    From twitter comments on this post;

    @yash
    @PrakashLab Manu, I was curious and did a little digging, I found a strong contender for your case here, they could be Chironomid (non-biting midges) egg masses as well.

    https://www.google.com/search?q=chironomid+eggs

  4. Manu Prakash says:

    More from twitter
    @yash

    Here are some interesting articles w.r.t bacteria and the egg masses. Spoiler( no antibacterial property there) 🙁

    Strangely they’re related(non phylogeny) to #Tardigrades too.. 😉

    RESEARCH ARTICLE
    Reflected polarization guides chironomid females to oviposition sites
    Amit Lerner, Nikolay Meltser, Nir Sapir, Carynelisa Erlick, Nadav Shashar, Meir Broza
    Journal of Experimental Biology 2008 211: 3536-3543; doi: 10.1242/jeb.022277
    https://jeb.biologists.org/content/211/22/3536

    And here is a paragraph that blows my mind:
    “ Chironomid populations and cholera control

    Chironomids are the carriers of the Vibrio cholerae bacterium, a human pathogen responsible for the fatal cholera disease. The bacterium, which feeds on the eggs, can be dispersed between water bodies by the adults (Broza and Halpern, 2001; Halpern et al., 2004; Broza et al., 2005; Halpern et al., 2006; Paz and Broza, 2007). This study suggests two ways to control chironomid abundance and dispersal and consequently to limit the persistence and spread of cholera: (1) decrease the number of preferred habitats for oviposition, and (2) direct the females to alternative, more attractive artificial habitats and then collect or destroy the eggs. The first strategy can be achieved by decreasing the percentage polarization of light reflected from a water body by increasing the reflectivity of the water. The second strategy can be achieved by creating artificial trapping ponds near natural ponds that will be more attractive to the females because of their high polarization reflection. This may be expanded to polarized light traps placed alongside specific water bodies (Kentaro Arikawa, personal communication). It is worth mentioning again our preliminary observation that tubs with white edges above water level are completely unattractive to chironomid females.”

  5. Manu Prakash says:

    And here is where the world becomes bizzare – @yash just posted this paper that Chromonid egg vases harbor “cholera” – yes; “the” cholera that makes people terribly sick and takes lives. It’s such a beautiful example where you begin by just asking – what (on earth) is that; and end up finding a remarkable connection with our own lives! Lego should make a song – not with “everything is awesome” – but “everything is connected” – specially in light of the current climate crisis!

    https://www.nature.com/articles/35083691

    More soon – will wait for them to hatch!
    Cheers
    Manu

  6. caroline_stefani says:

    Wow ! Really interesting, and a little scary. I also wish I wore gloves now, but as a microbiologist I found it fascinating.
    I was just getting ready to post the pictures when I saw your post. I will add them on twitter.

  7. Manu Prakash says:

    @caroline: can you make a microcosmos post with the data you have – as “part 2” post. The foldscope community is not on twitter.

    Cheers
    Manu

    1. caroline_stefani says:

      That makes sense. The post is out 🙂

      PS: still learning, I’ll get better with time 😉

  8. Manu Prakash says:

    When you post here – it automatically posts on twitter.

    M

  9. @Manu, did those eggs hatch by any chance?? Just checking..

    Cheers
    Yash

  10. laksiyer says:

    Fascinating. They are likely to have a defense angle in addition to preventing drying, perhaps against multiple predators such as fish, other aquatic invertebrates and even fungi. Would be good to test these in a formal setting. Its barely bigger than your fingertip @Manu, fantastic find.

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