You might expect an abundance of fauna and flora in tropical rainforests, colourful coral reefs or in densely wooded groves. But many of these habitats are uniquely positioned to encourage and sustain biodiversity, such as having a particular climate or source of water, which help support complex food chains.
Not all environments have these, with some being particularly extreme. However, even in some of the most unusual environments, you’ll still find life – as this list shows.
Deep sea hydrothermal vents
Hydrothermal vents are cracks in the sea bed, from which super-heated water spews out. These vents are commonly found in volcanically active places where tectonic plates are moving apart, such as in the depths of the West Pacific.
Here, scientists found that these vents not only release boiling water, but also levels of hydrogen sulphide (a toxic gas) and arsenic (a potent carcinogen) that would be deadly to most animals.
Amazingly, they found an animal happily living in the hottest parts of these vents: Paralvinella hessleri, a species of worm. These critters are able survive the high levels of arsenic in their bodies – neutralising it by absorbing sulphide from the surrounding seawater.
Other lifeforms found thriving in hydrothermal vents are Pompeii worms, one of the most heat-tolerant animals on the planet, and giant tube worms, which actually depend on the toxic waters of hydrothermal vents for survival.
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The Atacama Desert
The Atacama Desert in northern Chile is the driest non-polar desert on Earth. Its conditions are so dry that NASA has used parts of it to test Mars rovers.
Although some wildlife lives along the desert’s coastline and in river valleys, the harsh environment makes much of its central region nearly uninhabitable.
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But buried in its soil are microscopic worms that are classified in the same group of organisms as arthropods and tardigrades, which have a reputation for being very hardy. They are called nematodes.
Nemotodes can certainly adapt to extreme environments, such as the deep sea, Antarctica and mines that stretch kilometres down into the Earth.
Studies on the netamode communities in the Atacama Desert have shown that they are far more diverse than previously thought, with mean annual precipitation and seasonal temperature variation having a strong, consistent influence on genus richness prediction.
The studies of how these nematodes adapt in extreme environments helps to improve estimation of the ecological consequences of climate change, researchers say.
Salt lakes
Environments of extreme salinity, such as inland saltwater lakes and salt pans, are deadly to most animals, causing intense and rapid dehydration.
However, brine shrimp (you might know them as sea monkeys) are among the most resilient animals on Earth, able to tolerate water that is as much as 25% saline. This is 10 times saltier than the sea. The ability of these little crustaceans to live these inhospitable salt lakes mean they manage to avoid almost all predators. Now that's some hardy shrimp!
Deep ocean
Deep in the sea's abyss, thousands of metres below the surface, the pressure is at least 150 times higher than inside a car tyre. Surely nothing can survive down there?
It turns out that a variety of fish, squid, jellyfish and many other animals live in these extreme depths; able to do so because of their highly adapted physical attributes suited to high pressure.
The blobfish for example, has several adaptations suited to high-pressure environments, such as a soft, squishy body, soft bones, and very little muscle. In its aquatic environment, it looks like a normal fish. Bring it on land – and it looks like a gelatinous pudding!
Most deep-sea fish don’t have gas-filled swim bladders, which are difficult to inflate at great depth. Instead, their bodies are filled with jelly, boosting their buoyancy while avoiding implosion.
Tops of the Andes
Llullaillaco is a 6,739m-high volcano in the Andes, straddling the border of Chile and Argentina. Nothing grows on its summit, which is 2,000 metres above the range of green plants, yet biologists have spotted a yellow-rumped leaf-eared mouse living there, making it the highest-living mammal – we know about.
Otherwise known as Patagonian leaf-eared mice, these are fairly large mice, weighing around 55g and they are particularly recognisable by their large ears. With no vegetation at this high altitude, scientists are baffled as to what the Llullaillaco population of mice are feeding on.
The world’s highest mountain tops are under-explored by biologists, so the mouse's record for highest living mammal might yet be broken.
Terrestrial Antarctica
Due to the extreme cold, life on the rock and ice of the Antarctic continent is extremely limited. There are no native land mammals, reptiles or amphibians. However, a few organisms do survive there.
Nematodes are microscopic worms found in the soil – and they're even found on the coldest place on Earth. The species Scottnema lindsayae is particularly abundant on the continent and is endemic. It's one of three nematode species found in the McMurdo Dry Valleys: the driest desert on the planet.
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In the soil, nematodes capture and store carbon.
The Antarctic springtail is a species of springtail (a type of arthropod) native to Antarctica and Australia. It survives the freezing temperatures by building up antifreeze compounds, which lower the freezing point of its body fluids.
Like with other springtails, the Antarctic springtail is a useful bioindicator of pollution. In 2020, researchers published a study that showed that microplastics had entered the Antarctic food chain via springtails.
