However, in Mexico the tardigrade fauna is little known.A new project, which brings together researchers from the National Autonomous University of Mexico and the National Polytechnic Institute, plans to change that.Tardigrades may be practically invisible, but Jazmín García Román knows where they hide.Contrary to what might be thought of the so-called "most resistant beings on the planet", it is not necessary to enter the crater of a volcano or travel to an inhospitable glacier to find them.Instead, we march through Ajusco, a national park south of Mexico City where families often bike or hike on the weekends.After less than an hour of walking, Jazmín, a biologist from the National Polytechnic Institute (IPN), sees the perfect place to collect these peculiar microinvertebrates.She sits down in the mud and pulls a pen and several manila envelopes out of her backpack.On one of its faces, write down the coordinates and the altitude.Then she, she naturally, begins to take off from the ground little mattresses of bright green moss that she carefully puts in the paper bags.In short, it is not the place where she would expect to find the animal that could revolutionize space exploration."Tardigrades can reduce their metabolism or stop it for years," explains Jasmine, while she separates an emerald pad that is well attached to a rock with a knife and stores it in another envelope already labeled;If scientists figure out how this mechanism works, we could use it to enter a suspended state and make long journeys through the Universe.As bland as moss may seem, it is an ideal habitat for tardigrades.Their ability to retain water and resist desiccation provides them with a permanent liquid film in which to live.“They are aquatic”, adds García Román, although they also live in the ice or in marine environments, where they are more difficult to collect, she details.More than 250 years ago the "water bears" were first seen swimming in their microcosm.Since then, they raise more questions than answers.For years, their abilities and exceptional appearance made them jump from one taxonomic group to another in the classification of living beings;from being classified as arthropods (such as fleas or mites) to being related to a rare phylum of velvety legged worms (onychophorans).Today, tardigrades are considered a "thing" completely apart from anything else known, although somehow linked to these two (all three form a superphylum called Panarthropoda).The reality, says Enrico Ruiz, from the Department of Zoology of the National School of Biological Sciences of the IPN, "is that it is a little-known group."Despite its recent fame, only about 1,300 species have been recorded worldwide, and basic aspects of its life cycle are still not fully understood."Frankly, we don't know who we're dealing with," he concedes.For Jazmín García this is no surprise."It's a very difficult group to work with."In addition to their diminutive size—the largest species measure just 1,200 microns (µm), while the smallest are no larger than the diameter of a human hair—you must have a keen eye to tell them apart from other microlife like protozoa, nematodes, and rotifers."You can spend hours looking at moss under a microscope, but if you don't know how to look for it, you'll never see it in your life," he adds.The fact that few people worldwide dedicate themselves to studying them does not help either.The species described so far come from the efforts of just 320 authors, according to a count recently published by Jazmín.You can also read: The strange jellyfish that is capable of rejuvenating until it avoids its death“There are about 280 tardigradologists in the world now;most in Europe,” he says.In Mexico, at the beginning of the 21st century, practically no one was dedicated to this, and today there are only three groups that publish their findings in scientific journals: one in the north, another in the southeast and one more in the center of the country to which she and Enrico belong.“We have an outstanding debt with the Mexican tardigrades”, recognize the specialists.Although we are one of the countries with the greatest global biodiversity, only just over 70 species of this phylum have been recorded here.That is why, like modern Linnaeus, the team of biologists has set out to discover and classify the Mexican tardigrade diversity and determine where each species lives.“With these studies —continues Mariana García León, an undergraduate student at the Autonomous Metropolitan University (UAM), who this year joined the group of tardigradologists— we are opening a new field of research in Mexico, and that is very exciting.”Alba Dueñas Cedillo was captivated by water bears about 14 years ago.She was surprised how little she knew about them.“Why doesn't anyone study them?” She thought to herself.Most of her classmates—biologists from the IPN—had never seen one;not even her teachers knew specialists who could teach Alba to look for them.In a self-taught way, she and a friend of hers began to collect moss in which they imagined that there might be tardigrades.They put the mazacote to soak and spent hours in the laboratory checking that "juice", drop by drop, under the microscope."The hydration water loosens everything (including tardigrades, which tend to cling to the stems with their tiny claws) and you can see it in the water," she says.She soon understood why almost nobody investigated them: she saw pollen, mites, springtails, rotifers, nematodes, all kinds of microbial life… but not tardigrades."It was trying over and over again until your eyes couldn't take it anymore."She read that the samples had to be sieved.She recycled sieves from other laboratories and returned to the fray.At this point, her colleagues joked: "They don't exist, Alba, you're looking for dust... they're imaginary.""There must be," she repeated to herself.She wrote to a team of Italian specialists who recommended reducing the size of her samples, shaking and filtering.Then, at last, she saw something move.“I thought I was imagining it,” she recalls.She many times she had been fooled by grass and other microorganisms.After focusing better she had no doubt: she was a tardigrade."That first time was extremely exciting," says Alba, who recently received her doctorate.She now teaches others, like Jasmine, to bring these slippers out of hiding and work with them."Everyone likes to see them," she boasts when she visits them at the Institute of Biology of the National Autonomous University of Mexico (IBUNAM), where both polytechnics collaborate.As if it were a welcome ritual, they invite me to observe through the microscope.You are also interested: The 10-tonne sea cow that Georg Steller discovered more than 200 years ago“Little pig” or “little water bear” are perfect names to describe the tiny, chubby creature on the other side of the lens.Like a prairie dog sniffing the air or the plump caterpillar in Alice in Wonderland, the animaculus rises on its stubby hind legs and hovers there for a few seconds.His clumsy and slow movements make him look a bit cute;pretty even."They have no joints," they tell me."To move they move their appendages by means of pressure differences, like an accordion."Precisely to that peculiar and amazing way of walking they owe their name: tardigrade that comes from the Latin tardus (slow) and gradi (to walk).Despite this, the truth is that they advance very easily."They are faster than they seem," admits the master's student Cuauhtémoc Felipe Amezcua, in charge of the molecular analyses.“To manipulate them and extract their DNA we use micropipettes, but sometimes they stick to the plastic with their claws or they get stuck on the edge and we lose them.They are naughty".It seems that patience is essential to work with these beings.For a while I watch in fascination as the rotund tardigrade vacuums up everything around it.Under what appears to be its mouth it shelters a singular oral apparatus."These structures are called stylets and are responsible for sucking the nutritional material from their food," Alba adds.Some species only eat plants;others, like this one, feed on various microorganisms, including smaller tardigrades.The team claims I was lucky to see one alive.This moss was collected in 2021 and therefore the wolverine had been asleep for almost a year.While a little tap water was all it took to “wake him up,” it's not a foolproof strategy."We have this mistaken idea that all species are super-resistant, but they are not," says Alba Dueñas.“If not, how do you explain that in the same sample and the same type of hydration, some species can return to life and others cannot?Easy: some are more sensitive”.Do not leave without reading: The strange amphibian whose lungs grow at the beginning;then they mysteriously disappearThis makes the little known about these animals even more worrying: if not all species revive, how much microbial life could be being lost without us knowing?“We have observed that the diversity and abundance of tardigrades is affected by human impact —says Jazmín García—.In forested areas, but with disturbances (garbage, too many people), there are few or no tardigrades.So we think there is some anthropogenic effect, although we still don't know how it works."Extinctions of microscopic animals may exist, but because they are poorly studied they tend to be ignored."Most likely, the destruction of habitats could affect tardigrades due to their low mobility: if their habitat is lost, they cannot do much to move to a new one," says Wilbert Pérez Pech, a doctoral student at El Colegio de la Frontera Sur, who specializes in marine tardigrades and did not collaborate in this research.For a long time it was thought that tardigrades —and in general, most microorganisms— did not have distribution patterns like larger animals;instead, they were cosmopolitan, that is, they were everywhere.Extinctions, therefore, were not something to worry about.Their tiny dimensions and survival mechanisms, such as cryptobiosis (the suspension of their metabolic processes), allowed them to be dispersed by the wind or other living beings over long distances and colonize practically any corner of the planet.For years, tardigradologists ascribed animals found on different continents to the same species, providing evidence for the "everything is everywhere" hypothesis.However, in the mid-2000s, the advent of Molecular Biology called this into question.Through DNA analysis it was found that some animals located thousands of kilometers away but cataloged as the same were molecularly different.These were cryptic species, populations difficult to distinguish from each other.Unlike insects and other organisms, tardigrades can only be studied through the microscope mounted on slides.Related: A Hidden World: These Are The Microscopic Animals That Inhabit The World's Most Diverse Forests"Their size does not allow you to open them to see their internal anatomy" explains Jazmín.Therefore, to identify a species, those who study them rely on traditional morphometrics: they measure the minuscule proportions of their segments, the length and width of their legs, their claws, their mouthparts."Identifying species is a headache," Alba agrees.So much so that even for experts it can be difficult to differentiate between two tardigrades of the same genus or family but of different species.That is why today not only morphological analyzes must be carried out for each organism: DNA studies are essential to assign the correct species and avoid confusion.This paradigm shift also opens the possibility of considering that these microscopic beings have limited geographic ranges or even that some may be endemic (inhabiting only one place).In April, the team of researchers published —together with several colleagues from both the UNAM and the IPN— a strategy to discover the distribution patterns of Mexican tardigrade biodiversity.In essence, they are creating a map of where they live.As a starting point, they have begun to sample the Transversal Neovolcanic Axis, a chain of volcanoes that joins the Sierra Madre Occidental and the Sierra Madre Oriental, and where the highest peaks in the country are located.The Ajusco, where we were collecting, is part of said massif."Mountainous systems contribute as corridors of diversity," explains Francisco Armendáriz Toledano, specialist in Forestry Sciences, from IBUNAM."That is why they are interesting places to learn about the distribution of this group and the role that Mexico had in its diversification."Its objective —unlike its object of study— is gigantic.Although so far only less than a hundred species are known in the country, the group estimates that it could be home to almost 300."More than half of the Mexican territory has no records of this phylum," they point out, so the first big step is none other than sampling moss and then characterizing the species they find.Read more: They find a new species of tardigrade, the microscopic animals that can live in outer spaceWith this, explains José Juan Flores Martínez, from the IBUNAM Geographic Information Systems Laboratory —who together with Enrico Ruiz and Francisco Armendáriz lead the Mexican Tardigrades project—, they plan to found the First National Collection of Tardigrades whose records will be shared between UNAM and the IPN."The idea is to investigate these organisms, but also to create a school of specialists," comments Flores Martínez.The company is rigorous.It will require a lot of field work, going up and down hills and stopping to pull up beds of moss at certain heights, just like Jazmín, José Juan and their companions did during the more than five hours that our excursion to Ajusco lasted.Already in the laboratory, Alba and the rest of the students will have to get these little devils out of their hiding places, prepare them in slides and begin the complicated task of identifying whether or not they are new records for Mexico and, with a bit of luck, some new species.Their efforts have already begun to bear their first fruits: in 2020 they characterized Minibiotus citlalium sp.nov., a new tardigrade from the Iztaccíhuatl volcano whose name alludes to the beautiful star-shaped figures on its back.And right now the team is preparing to unveil a second species never seen before."If we had complete inventories of tardigrades, we could advance in the study of their application as environmental quality indicators and in many scientific areas where they have been seen as potentially useful," Pérez Pech considers regarding the intention of the researchers from the capital.Other uses for tardigrades are tissue regeneration and protein preservation in the pharmaceutical industry.Alba sees their future as indicators of forest health: “Some species are very sensitive to lack of water.We could see its changes under drought conditions.”For his part, Francisco Armendáriz seeks to find a species that works as a model for cell physiology.“Tardigrades have a series of proteins that repair DNA.If it is possible to know what they are and understand how they work, it could have important biotechnological applications”.Much remains to be discovered about the Mexican tardigrades, but Alba and Jazmín plan to uncover their secrets no matter where these water bears are hiding.This text is part of the September 2022 edition of Muy Interesante in its printed format.The ancestor of mammals that swam like hipposThey find an animal that looks like an elastic banana with a tail in the marine abyssesWhat are the mysterious holes that were found at the bottom of the Atlantic Ocean?They discover a strange creature with tentacles and flower shape at the bottom of the seaTELEVISA SA DE CV EDITORIAL ALL RIGHTS RESERVED.TBG - EDITORIAL TELEVISA - NEWS/INFORMATION - GENERAL NEWSThis website uses cookies to improve your experience while you navigate through the website.Out of 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