Field of Science

Protists gone motile! (and a Euglenid metaboly video)

So I caved and got me a Youtube account, partly inspired by a comment in the previous post. Accumulated half a metric shit ton of random protist videos by now, and compressing them for Bloggers crappy video sharing system would take way too much time, and I barely have the time to grab stills and post them here. So finally there's a suitable outlet for my raw video data – maybe someday when I'm not going completely insane and falling behind on a million things I didn't really have time for in the first place, I may put together a properly edited video. But don't hold your breath for it...

We have some pretty awesome microscopy and video equipment in the lab, and I'm lucky to have a PI nice enough not to mind some of us using it to fuck around with random samples in the middle of the night. I hope it may help bring the microbial world a little closer to you, and add a whole new dimension of time to our protists.

Let's start off with some euglenid metaboly, since it's quite hard to talk about without seeing it. Actually, the true reason is that it's about the first thing my cursor landed on when I opened my pile of videos for file conversion. But just as we ascribe purpose to evolutionary happenings, we can likewise ascribe purpose to my selection here ;-)

Since I'm lazy and behind on about a million things (to the point where I must mention it twice), just gonna copy the short description I wrote for this bug on the YouTube page. Enjoy!

This is a heterotrophic euglenid, perhaps a Peranema sp., exhibiting metaboly in all its splendour. The cell might be slightly squashed or otherwise damaged, keeping the flagellate conveniently in one place. The clear vesicle near the base of the flagellum that grows and shrinks is the contractile vacuole, the flagellate's analogue of the animal secretory system. At the tail end are refractile starch granules used to store energy.

Metaboly is a form of cell movement that is most famously exemplified by ciliates, but also known in some other flagellates. It appears to be caused by the specific arrangement of microtubule (cell skeleton) bundles at the cell periphery, and greatly enhanced by the 'armour plates' of the euglenid surface, which is lined with long pellicle strips going from the flagellar insertion all the way to the tip of the 'tail' -- as the cell twists about, the strips slide against each other and result in this movement. Euglenids with fused pellicle strips, like Phacus, are incapable of metaboly. The function of this movement is unknown, and there may not be any in particular.

The hairy thing next to the euglenid is a badly mangled ciliate.

Freshwater, Apr 2011, Vancouver
And please let me know if you have any requests, comments or suggestions for these videos. I'm new to the world of moving pictures (instead I see videos as image sequences, like any proper cell biologist ought to...), so I'm in an even greater state than usual in not knowing what the hell I'm doing.


  1. nice!
    a moving picture worth a thousand words hehe

    I saw some flagellate moving weirdly like that, now I guess I can say they were euglenids.

    you said we can make requests, so, if possible, some videos with ameboid cercozoa or dinoflagellates, i have always found them fascinating!


Markup Key:
- <b>bold</b> = bold
- <i>italic</i> = italic
- <a href="">FoS</a> = FoS