A Protist’s Worst Nightmare

Jennifer Frazer — Sat, 12 Mar 2011 15:43:33 +0000

This video* is hypnotic and illuminating — one might even say joyful, and it is joyful to me to watch it. But if I was a bacterium, alga, or protist (what these rotifers are hoping to get for dinner), I’d feel a bit different. That gauntlet about halfway through the video? Talk about a swirling vortex of rotiferan doom, with their mechanical jaws snapping like clockwork at the bottom of each whirling trap (look for the jaws chugging like pistons about 1/4-1/3 of the way down each gullet).

Repeat after me: “The penitent protist shall pass . . .the penitent protist shall pass . . . ”

As you can see rotifers (literally “wheel bearers”) are so called from the accessories on their foreheads involved in hoovering up dinner. And they are truly amazing creatures. To learn more about bdelloid rotifers (including some gorgeous SEM shots of their jaws) and their alternative lifestyles, see two posts from early in this blog’s life: Lesbian Necrophiliac Bdelloid Rotifers (and the Scientists who Love Them)Parts 1 and 2. The above video provides a good illustration of why they are called “bdelloid”, or leech-like rotifers. They move just like inchworms or leeches**:

Psi Wavefunction did point out, however, that rotifers are *not* the smallest animals. Rotifers are animals (not protists), but as for what the smallest animals might be, I will leave for another day.

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*for which I am endebted to the twitter feed of Chris Mah at the Echinoblog

**which are, by the way, annelids (from the last post — see the tree at the bottom) in the Clitellata — look for the Hirudinea. Look for the earthworms just above them in the Lumbricidae. And, just below them but also in the Clitellata (and hence annelids) is the sludge worm Tubifex Tubifex in the Tubificidae — from here, remember?)

Lesbian Necrophiliac Bdelloid Rotifers (and the Scientists who Love Them): Part 1

Jennifer Frazer — Thu, 30 Apr 2009 03:47:12 +0000

So you’ve been having a rough decade eking out a living as a bdelloid rotifer, living in the soil, some moss, or a small vernal pool. First, it stopped raining a few days after you hatched. Then you entered a period of dried-up stasis in which your cell membranes ruptured, metabolism ground to a halt, and DNA may have been cuisinarted. Bummer.

But lucky for you, it started raining! And guess what, it’s raining genes! (Cue The Weather Girls) Which is great news, because your species is all female and hasn’t had sex in 100 million years. Hallelujah!

Scanning electron micrographs showing morphological variation of bdelloid rotifers and their jaws. We're going to need a bigger microscope (apologies to Roy Scheider and Peter Benchley). Photo by Diego Fontaneto, available under a Creative Commons Attribution license. Click photo for link.

As described in this little article over at discovermagazine.com, without a way to exchange and recombine genetic information, many animal species tend to degenerate and disappear over time (thus the joy of sex) because they lack efficient ways to generate novelty that can help them adapt to changing environments. That’s OK — when you’re a bdelloid rotifer, you can do it Hoover style: just vacuum up whatever stray DNA happens to be in your environment, including the genes of whatever it was you might have recently had for dinner (note to self: glad am not bdelloid rotifer). Plants, animals, bacteria, fungi, and who knows? — you might even get lucky. You might manage to incorporate some variant versions of your own species’s genes, thus escaping the cruel grind of creeping genetic obsolescence.

Coming soon: Part 2: So what is a bdelloid rotifer anyway?

bdelloid rotifers – The Artful Amoeba

A Protist’s Worst Nightmare

Lesbian Necrophiliac Bdelloid Rotifers (and the Scientists who Love Them): Part 1