Tardigrades have faces that only a mother could love, maggot-like bodies, and – at half a millimeter in length – are inherently un-pettable. Moreover, the eight-legged micro-animals are not rare; they’re literally found everywhere on Earth.
And yet, thanks to their casual near-indestructibility, “water bears” have earned quite a fanboy following.
On that note, a new species has just been discovered in a Japanese parking lot, and the Internet is abuzz.
Now officially described in a PLOS One paper, Macrobiotus shonaicus was first encountered when study author Kazuharu Arakawa took a scraping of moss bordering the paved area outside of his apartment building in the Shônai region.
“Most of [the] tardigrade species were described from mosses and lichens – thus any cushion of moss seems to be interesting for people working on tardigrades,” Arakawa told Live Science.
After bringing his sample of tardigrades back to the laboratory, something unexpected occurred. The individuals were not only thriving in the artificial environment, they actually began to reproduce; a rare event for these organisms. And when Arakawa looked at the resulting eggs under scanning electron microscopy, things got even weirder.
Progressively zoomed images of the filament processes covering the M. shonaicus eggs. Scale in micrometers. Stec et al./PLOS ONE, 2018
The eggs’ solid, round shape placed them in the large tardigrade taxonomic group called Macrobiotus hufelandi, and yet the surface was covered in hundreds of volcano-shaped structures, each topped with a ring of tentacle-like filament protrusions. This feature suggested the tardigrade was related to two species found in Africa and South America.
Unlike other Macrobiotus hufelandi tardigrades, however, the specimens did not eat the tiny aquatic animals known as rotifers. They were observed happily munching on algae instead.
A subsequent genetic analysis revealed that the mystery tardigrade’s DNA sequence was different from all other on record. At this point, Arakawa brought in some help: Polish tardigrade experts Daniel Stec and Łukasz Michalczyk. Together, the trio determined that M. shonaicus was indeed a new species – the 168th to be identified in Japan and the first new member of the hufelandi group to be found in East Asia.
Macrobiotus shonaicus, scale in micrometers. Stec et al./PLOS ONE, 2018
In addition to the novelty of finding another species, the discovery of readily mating tardigrades will soon yield insight into the relatively mysterious tardigrade lifecycle.
“It is an ideal model to study the sexual-reproduction machinery and behaviors of tardigrades,” Arakawa said. “We are actually already submitting another paper describing their mating behaviors.”
Another takeaway from the research? Never discount the rich natural universe that exists in your own backyard.
Now, here’s a video of an M. shonaicus tardigrade pooping.