Niesporczaki (called water bears in English) are invertebrates that already have a permanent place in popular culture. It is one of the toughest animals we know. They can survive in a vacuum, at temperatures close to absolute zero, under conditions of high ionizing radiation, and even for decades without water. It’s been sent to the Moon before, and recently tested to see if it would survive quantum entanglement. In the meantime, however, we still don’t know much about how tardigrades cope in everyday situations.
After a series of otherworldly experiments conducted around the world, researchers from Poland focused on searching closer to Earth and examined how tardigrades coexist with their neighbors – snails. Because both snails and tardigrades – they live in similar areas and like similar environmental conditions – like moist, shaded places, preferably filled with algae. The common ecosystem of these two types of invertebrates does not need to search far. – We managed to find both snails and tardigrades, for example, on the wall near the hospital in Pozna – researchers from Adam Mickiewicz University laughed in an interview with PAP.
– I study snails, Melina studies tardigrades. Since we love each other, we decided to conduct joint research and check the relationships between these animals – says the first author of the work, Dr. Zofia Książkiewicz-Parulska from Adam Mickiewicz University. Milena Roskovska adds: – Our research makes us realize that we don’t have information about the interactions between animals that live in our immediate vicinity.
Do snails help tardigrades?
Zoologists were particularly interested in whether the snails could help their much smaller invertebrate teammates move. Although tardigrades have eight legs, due to their size (0.01-1.2 mm), they move much slower than a snail, which has only one leg, but can climb up to several meters per week. For a snail man, speed is nothing. Tardigrades (Latin Tardigrada means to walk slowly) move at a maximum of 23 mm per hour – it’s like traveling by train.
In the experiment, it turned out that tardigrades actually stick to the snail’s mucus and thus overcome the impenetrable silicone barrier, thus being transported to new places where they would not have entered themselves. Unfortunately, snail snails are not a friendly environment for tardigrades. Two-thirds of these little ones – even those capable of space flight – do not survive being abducted by a snail.
Melina Roskowska explains that tardigrades owe their endurance to the ability to enter a state of anhydrosis. When living conditions become difficult, tardigrades close themselves in a narrow “barrel”, limit their life activities to a minimum and continue until the time, conditions improve. They can stay in this state for a very long time.
So why is snail slime a problem for tardigrades? The thing, researchers think, is that snail-hijacked tardigrades feel the moisture of the mucus and wake up from the anhydrous disease. However, snail mucus dries quickly, and unfavorable conditions quickly make themselves felt. Some tardigrades may not be able to quickly return to a state of anhydrosis, resulting in their death.
However, researchers state that tardigrades can reproduce by parthenogenesis – so one individual is enough to give birth to offspring. So, even if some of the bears kidnapped by the snails did not survive the snail’s flight, all the inhabitants still benefited from it – those who survived would gain control of new territories.
The researchers have an idea for another joint research – they want to check how tardigrade eggs, which can also stick to mucus, deal with snail mucus. The proportion of happy journeys may be greater than among tardigrades in the case of anhydrous disease.
The research appeared in the magazine Scientific Reports.
PAP – Science in Poland, Ludwika Tomala
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