(ORDO NEWS) — Snail travel may not seem like the fastest way to get around, but it’s faster than walking…if you’re a tardigrade.
Eight-legged, adorably pot-bellied tardigrades nearly microscopic organisms also known as water bears or moss piglets can travel much further on land snails than they could on their own, a new study has found.
But while snail riding helps tardigrades disperse to new places, snail slime coating is often fatal to tardigrade riders.
tardigrades are 0.002 to 0.05 inches (0.05 to 1.2 millimeters) in length and can live almost anywhere on Earth where there is liquid water: in oceans, in rivers and lakes, in damp clumps of lichens and mosses, growing on rocks and trees.
Water bears can also endure conditions that are lethal to most life forms, such as extreme temperatures, crushing pressure, ultraviolet (UV) radiation, the vacuum of space, and even being fired from a rapid-fire cannon, using a superpower known as anhydrobiosis – the expulsion of almost all water from their body. .
In this parched and twisted form, called the tung state, tardigrades can survive in harsh environments and persist for years; some tung tardigrades frozen for 30 years were successfully resuscitated in 2016 and began breeding immediately, Live Science previously reported.
And recently, researchers have discovered that active and tunneling tardigrades can be picked up and carried by land snails that share their habitat.
Although tardigrades can swim and walk, their tiny feet keep them from getting far. Therefore, the tardigrad in search of a new place of residence needs outside help, such as wind, running water, or a helpful host animal that is wet enough to keep the traveler alive.
Little is known about how tardigrades interact with snails in their natural habitat, but because aquatic bears often live side by side with land snails (which are known for their wetness), the researchers suspected that snails could potentially be “the perfect vehicle for tardigrades.” to travel from place to place, according to a study published April 14 in the journal Scientific Reports.
“After checking the available literature, we found that this topic has been largely unexplored,” says lead author Zofia Książkiewicz-Parułska, Associate Professor at the Institute of Environmental Biology at Adam Mickiewicz University (UAM) in Poland, and co-author Milena Roszkowska, PhD student in the UAM Department of Bioenergy.
The only previous study on the subject – more than 55 years ago – described observations of tardigrades moving inside the guts of snails after they were eaten and then exiting in the faeces of shellfish, the researchers emailed Live Science.
To test the hypothesis of hitchhiking tardigrades, the authors of the study collected grove snails (Cepaea nemoralis) and tardigrades Milnesium inceptum; the two species coexist in the terrestrial ecosystems of Western Europe, and both species are most active in humid conditions.
Grove snails have a shell diameter of up to 0.9 inches (22 mm), making these mollusks good candidates for carrying tardigrades, the researchers said.
In their experiments, the scientists sent snails to crawl over drops of water and bits of moss containing tardigrades to see how many “piglets” the snails picked up.
Active and tunneling tardigrades easily stuck to the mucus-covered bodies of the snails for short trips; snails carried 38 tardigrade companions from water drops and collected 12 tardigrade ichneumons from moss.
In some experiments, researchers surrounded a water pool with tardigrades with a physical barrier; under these conditions, the only tardigrades that crossed this border did so with the help of a snail’s “vehicle”, the study says.
But the sticky mucus of the snails had a deadly downside as it dried on the tiny bodies of the tardigrades.
Only a fraction of the tunas covered in dried snail slime – about 34 percent – were able to revive after 24 hours. In comparison, 98 percent of the control group tunas that were not covered in mucus became fully active again once they were rehydrated.
Snail slime is mostly water, but it dries out quickly, and the slime-covered tunas that were briefly revived by the water in the snail slime may not have been able to return to the tuna state fast enough as the mucus around them hardened and they were frozen in ” very strange positions” that were not fully formed tuna, the scientists said in an email.
Other powers can carry tardigrades. much further than snails; previous research has shown that gusts of wind on glaciers can carry tardigrades. over distances of more than 620 miles (1,000 kilometers), the study authors write.
However, the tardigrade, riding the wind, may be in a place not too hospitable for water bears. The snail’s journey will likely take its rider into an environment similar to where it started, where tardigrades (and snails) are likely to thrive.
Further experiments could confirm whether tardigrade eggs can also travel on snails and test how far a tardigrade can travel on a snail, the researchers say.
But even if a traveling tardigrade’s new home is only a few centimeters away, it’s still far enough away to improve genetic diversity among different water bear populations, the study says.
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