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A polyp’s pet rotifers

As penance for irregular posting, have a pair of seemingly-symbiotic rotifers in a cnidarian (jellyfish) polyp. There were several of them on several polyps, and they seemed not to mind the tentacles (loaded with stinging cells containing a harpoon-like weapon with paralytic abilities).

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


As penance for irregular posting, have a pair of seemingly-symbiotic rotifers in a cnidarian (jellyfish) polyp. There were several of them on several polyps, and they seemed not to mind the tentacles (loaded with stinging cells containing a harpoon-like weapon with paralytic abilities). Unlike the dividing ciliate in the corner -- standing still as it appears to have been paralysed by the stinging cells. Curiously, instead of blowing up, it just stops moving. The morphology remains intact. Perhaps a potential method for immobilising protists for better imaging?

Here's a toe of the rotifer rooted deep in the polyp. The rotifers were alive and feeding. Might be some sort of a commensal relationship where they take advantage of the polyp's easier access to drifting detritus, as well as protection from some predators. The rotifers might also help generate extra current. This is all baseless hypothesising out of my ass though, so please forget everything I just wrote!

Since I'm apparently on an invert spree, just for fun: a ctenophore, aka comb jelly. Despite being called jellies and appearing vaguely jellyfish-like, they seem to not only be a completely separate branch from cnidarians (containing "true" jellies), but perhaps a lineage as deep as sponges in the animal tree. Fascinating organisms. Also, two anuses.


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Finally, a protist. This is Noctiluca, a bioluminescent dinoflagellate that is also fairly big for a single cell -- 1-2mm. You can easily see them in a planktonic water sample. This picture was taken through a dissecting scope. They're basically bloated bubbles with a little bit of actual cytoplasm. Marine biology stations are busy and highly-distracting places. I have some rare/new organisms to show too, but later...

About Psi Wavefunction

I first encountered the wonders of the protist realm back in childhood, when a murky droplet of pond scum was revealed by the microscope to entail an alien world in its own right. It took another decade to discover there was a field and a community dedicated to these organisms, and I bade farewell to the study of more familiar big things. As a kid I was also fascinated by tales of exploration of the New World, as well as those of fantasy worlds. I was then sad that the age of surveying new landmasses on earth was over, and that human extraterrestrial adventures are unlikely to happen within our lifetimes. It seemed everything was discovered already. But that could hardly be further from the truth -- all that is necessary to begin one's own Age of Exploration is a new approach or perspective, and a healthy does of imagination. Since reality has conjured far more than the human mind alone ever could, science yields a way to write stories much wilder than fiction. All one needs to access the alien world of microbes around (and inside) them is a shift of scale by simple glass sphere.
I'm currently finishing up my undergraduate degree in Vancouver and in transition career-wise, hopefully to end up in graduate school soon. I was born in Russia (and speak the language) and spent most of my life in US and Canada. In addition to protists, I'm fascinated by evolution, including that of culture and languages, diversity and biology of cells and how they self-organise, linguistics and anthropology, particularly of the less talked-about cultures, sociology of science and plenty of totally random things that snag my attention.
Banner image was kindly post-processed and enhanced by my friend: an accomplished comic artist who goes by Achiru.

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