The tardigrades are certainly strange. Dehydrate them in glass, take them out of a gun, and once you rehydrate them, you can have a living creature. Their exteriors aren’t the only thing that’s difficult either, as scientists discovered last year that they also had special DNA shielding proteins.
But if we take a step back from his immense ability to be beaten, there are many other mysterious things about it. For starters, how do these little creatures walk?
After all, they are one of the only animals with small soft bodies like this tin walk, in addition, is one of the smallest animals with legs that we know.
Tardigrade walking on soft ice. (Nirody et al., PNAS, 2021)
“One of the funniest and initially most amazing things about the tardigrades going towards me was that … hopefully they were there.” Rockefeller University mechanical biologist Jasmine Nirody wrote on Twitter.
“They have a regular gait and look remarkably like those of much larger animals!”
Therefore, Nirody and his colleagues recorded late paths of the Hypsibius dujardini species to analyze their gait and leg coordination, and we can enjoy the results.
A tardigrade walking on stiffer ice. (Lisset Duran)
“We didn’t force them to do anything. Sometimes, they would be very creepy and just want to walk on the substrate,” Nirody says. “Other times they saw something they liked and ran towards it.”
The team caught tardigrades and traversed different surfaces, finding that their pattern of passage is very similar to insects, although the two groups were of incredibly different sizes and were made of completely different things.
Tardigrade walking on a stiff ice with claws visible. (Nirody et al., PNAS, 2021)
The team also recorded the little boys trying to walk on smooth glass (they didn’t get much to the smooth surface) and on ice with two different levels of stiffness, to find out how this changed their gait in different conditions.
A supposedly unhappy tardigrade on glass. (Nirody et al., PNAS, 2021)
“We find that tardigrades adapt their locomotion to a‘ galloping ’coordination pattern when they walk on softer substrates,” the team writes in a new paper.
“This strategy has also been observed in arthropods to move efficiently on flowing or granular substrates.”
Why tardigrades walk as much as insects remains an open question. Researchers are not sure if there could be a potential common ancestor with insects or if the walking shot evolved separately in both organisms.
The research has been published in PNAS.