This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
Pseudotrichonympha pearti. Credit: del Campo et al. 2017
There really are an extraordinarily large number of weird things that live in the back sides of insects. Just last week I wrote about amoebas shaped like candy canes and boomerangs that live inside the posteriors of aquatic insect larvae, getting by on whatever they can glean from what the insect didn’t eat.
But another incredibly fertile place for such critters is the guts of termites. As anyone who’s battled a termite infestation knows, they eat wood. The microbes that live in their guts are often not passive gleaners but active helpers of their hosts, breaking down the extraordinarily tough fibers of lignin and cellulose that make up the hard backbone of wood. These biochemicals are so strong and resistant to degradation (which is why plants use them in the first place) that only select groups of organisms on Earth are capable of digesting them. Most of them are microbes; others are fungi. Animals get around this difficulty by recruiting microbes with these talents.
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But rather than use small and relatively low-profile bacteria or archaea, termites seem to employ – among others – glam rockers of the microbial world: shaggy, extravagant, grooving protists. Three new species just discovered in the guts of termites from Fort Lauderdale, Florida, and (I am not making this up) Mount Glorious, Australia were accordingly named after the formerly follicularly-blessed Canadian rock band Rush: Pseudotrichonympha leei, P. lifesoni, and P. pearti. And they made a video about it. An awesome video. Make sure you hit the box in the lower right corner to enlarge the video and check out how these babies move [CAUTION: Loud Prog Rock]:
As you can see, Pseudotrichonympha cells are gigantic – up to nearly half a millimeter long by 100 micrometers wide in the case of P. lifesoni. Since a termite may be only 5 millimeters long. In human terms, that would be like hosting a colony of organisms half a foot long and 1-2 inches wide inside your gut. The protists are covered by long rows of thousands of flagella, tail-like organelles that whip back and forth to propel cells (sperm being the most famous example). The rows of flagella seem to radiate from a conical cap at the top of the organism, which it shimmies like a belly dancer.
Let me point out a few small but gorgeous details. Intermittently between :17 and :28 you can see hair-like corkscrew-shaped spirochete bacteria – of which the organisms that cause Lyme Disease and syphilis are members -- spinning and gliding around the protist. Their wriggle-based propulsion system featuring an internal flagellum is extraordinary and I have written about it before
here. These bacteria help show just how enormous Pseudotrichonympha is.
Note the beautiful dimpled and striated textures near the cap of this microbe at 1:17.
At 1:25, note the fields of flagella undulating like a seagrass bed.
The sequence at 2:15 is so gloriously awesome you almost can’t believe it’s real. Check out that mane waving like feathered hair in the fan of a Whitesnake video.
What’s most extraordinary, however, is the discovery of a possible new and bizarre organelle, the little machines that run cells. Finding a new organelle is rare, and this one is particularly perplexing and mesmerizing. They've dubbed it the rotatosome, which sounds suspiciously like something “as seen on TV”. There was only one per cell, but they were not able to determine if there was one in every cell. It also had some sort of tube attached which is visible in the video at 1:44 and 1:51, which seems to send material into the rotating sphere.
As you saw, the scientists comfirmed the rotatosome was not a symbiotic microorganism living inside by the protist by checking it for DNA with a dye that sticks to the genetic material. Though the nucleus lit up with DNA-staining dye, the rotatosome did not. Whatever it is, it doesn’t have its own genes.
As odd as these creatures seem, they may be near ubiquitous in the Rhinotermitid family of more than 300 termite species. Yet only about a dozen species have been described. DNA scans of the hindgut of termites have revealed that undescribed species probably outnumber described species by a ratio of at least five to one. Given that there
are 445 million tons of termites on the planet (and only 360 million tons of people), and in spite of the fact you have never heard of them, Pseudotrichonympha are extremely common -- and fabulous! -- Earth citizens.
Reference
Javier del Campo, Erick R. James, YoshihisaHirakawa, Rebecca Fiorito, Martin Kolisko, Nicholas A. T. Irwin, VarshaMathur, VittorioBoscaro, Elisabeth Hehenberger, Anna Karnkowska, Rudolf H. Scheffrahn, and Patrick Keeling. "Pseudotrichonymphaleei, Pseudotrichonymphalifesoni, and Pseudotrichonymphapearti, new species of parabasalian flagellates and the description of a rotating subcellular structure." Scientific Reports 7 (2017): 16349.