Sunday, June 7, 2009

Living Corkscrew

One of the most mesmerising features of the microscopic organisms that live in wet places is the variety of ways in which they get around. Some use rhythmically beating hairs (cilia), for motive power. Others, like amoeba, simply flow over flat surfaces. Euglenoids – minute photosynthetic organisms that are ubiquitous in wet places – blur our concepts of what is an animal or plant (they are neither) and can crawl over wet surfaces and even change shape, but mostly they use a long flagellum, whipping it through the water as the driving force for their movements. One of the most extraordinary euglenoids is this one, called Phacus, which adds an extra twist to the wacky ways of moving by being twisted into a helix. So when it beats its flagellum it corkscrews through the water, as you can see in the video. It's less than a twentieth of a millimetre long.



  1. Fabulous! The word 'euglenoid' tickled a dormant brain cell and made me fish out a dusty old paperback that I haven't looked at in years - Ralph Buchsbaum's 'Animals without Backbones'. First published in 1938 and still in print I gather - Vol 1 is great for an accessible whizz through the mini world.

  2. A really fascinating life form. It can certainly get quite a turn of speed with its corkscrew shape.

  3. Hi Nyctalus, modern natural history publishing seems to be obsessed with vertebrates but I find the microscopic end of the living world at least as interesting.

  4. Hi Midmarsh John, when you watch them under the microscope their flagellum sometimes gets attached to the slide and then they just spin around on the spot, before breaking free and whizzing off..


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