Despite their death-defying powers, tardigrades are terrible at traveling long distances, according to recent research, though the podgy tiny moss piglets may be able to overcome this handicap by hitching rides on snails. While snails are known for their sluggishness, the authors of the study published in Scientific Reports believe that going on such a gently rise is safer than being swept away by the wind or larger animals. With their woefully stumpy legs measuring only a fraction of a millimeter in length, tardigrades struggle to go very far and must rely on external stimuli to help them relocate.
According to previous studies, the cute little water bears are occasionally transported in the stomachs of snails or birds before being spat out later on. To survive such a travel, tardigrades enter a frozen condition, which they acquire by emptying all of the water from their body through a process known as anhydrobiosis. This enables them to withstand even the most grueling experiences, such as space flight.
The microscopic beanbags rehydrate and continue their tardigrade responsibilities and projects once they are in a more hospitable habitat. Researchers opted to investigate the animals’ ability to hitchhike on the backs of snails in a series of lab experiments because they often share their habitat with the mollusks. They did this by enclosing tardigrades in silicone enclosures within petri plates containing grove snails. The tardigrades were permitted to nestle up under a pillow of moss in some dishes, whereas others had nothing but water droplets for them to float around in.
Only in the presence of snails were the tardigrades able to escape their silicone enclosures, and none were able to do so when the snails were not there. “As a result, we believe the snails were in charge of tardigrade transportation,” the researchers wrote. The studies with moss, on the other hand, resulted in considerably fewer passengers aboard the snail express than those using only water. This could be because tardigrades tend to bury themselves inside moss bundles, which reduces their chances of being picked up by a snail, according to the researchers.
While there have never been any reports of snail-surfing tardigrades in the wild, recent study has shown that the tiny creatures may be carried up to 1,000 kilometers (621 miles) by air currents. When riding on the wind, however, “the environment at the last stop is unpredictable and may be unfavorable for a tardigrade,” according to the study’s authors. “A snail, on the other hand, is a vehicle oriented to a specific type of microhabitat,” they explain, adding that “if a snail will take a tardigrade (or tardigrade egg) for a ride, the passenger will [probably] be dropped off within a suitable environment.” Snail travel, as appealing as it may appear, has one significant drawback: deadly snail mucus.
Because this slimy substance is primarily water, tardigrades begin to rehydrate almost quickly after coming into touch with it. The mucus, on the other hand, dries quickly, and tardigrades struggle to adapt to such a drastic change, frequently failing to re-enter a tun condition in time to survive. As a result, just 34% of tardigrades slimed survived their journey, compared to 98% of tardigrades who did not come into touch with snail mucus. It’s sometimes safer to stay at home.