Does the idea of living beneath an alkaline lake or in toxic, lightless waters appeal to you? It doesn't bother this collection of extremophiles, creatures who thrive in... well, extreme environments! Take a look at...
The alkali flies of the lake spend their early life beneath the surface, but their big party trick is returning beneath the water as adults. The grown flies trap a layer of air around their body using tiny hairs, then crawl beneath the water to forage. Without this air bubble, the flies would find it hard to survive or even escape the mineral-rich waters of the lake!
The flies and their larvae are extremely good sources of fat and protein, so much so that the native tribes of the area (the Kutzadika’a) harvest the pupae to be used in stews.
Not weird enough yet? The snail doesn't actually "eat" anything. Most of its digestive system has atrophied, leaving a massively enlarged throat pouch - which the snail uses to "farm" chemosynthetic bacteria. These microbes turn the minerals being jetted out of hydrothermal vents into food, some of which the snail siphons off!
Despite this, a community of microbes have been found living in tiny cracks within the stones, feeding on hydrogen released by water when it's "cracked" by ambient radiation. It's not an easy life though, and researchers theorize that they microbes have a very slow reproduction rate - possibly over a century between generations.
- The Alkali Fly: Beneath the Corrosive Mono Lake
- The Scaly-Foot Snail: Toxic Waters Near Hydrothermal Vents
- Picrophilus and Sulfolobus Archaea: Boiling Acid
- Endoliths: Radioactive Rocks Three Kilometers Below the Surface
- Tardigrades: Almost Anywhere There's Water on Earth... and Beyond?
- Paradise Beneath the Antarctic Ice... or Life in Space?
The Alkali Fly: Beneath the Corrosive Mono Lake
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| Mono Lake is almost bleach... (Levan Badzgaradze) |
North America's Mono Lake sits at the end of a river system and has no outlet - meaning that water entering the lake only leaves when it evaporates. All the chemicals and run-off picked up by the river end up being collected and concentrated in Mono Lake, producing salty and alkaline (PH 9.8 - household bleach is around 11) waters. Humans can swim in the lake without any real harm, but getting water in cuts or the eyes is painful - and can destroy clothing and damage boats with prolonged exposure. Though the water is basically bleach, the lake is home to a unique kind of fly that wanders beneath the surface of the lake!
The alkali flies of the lake spend their early life beneath the surface, but their big party trick is returning beneath the water as adults. The grown flies trap a layer of air around their body using tiny hairs, then crawl beneath the water to forage. Without this air bubble, the flies would find it hard to survive or even escape the mineral-rich waters of the lake!
The flies and their larvae are extremely good sources of fat and protein, so much so that the native tribes of the area (the Kutzadika’a) harvest the pupae to be used in stews.
The Scaly-Foot Snail: Toxic Waters Near Hydrothermal Vents
Perhaps the only organism that would set off a metal detector while naked, the scaly-foot snail covers its exposed flesh in iron-plated scales!
This mollusk lives between the boiling waters of hydrothermal vents and the icy depths of the deep sea, in an environment with plenty of toxins but little oxygen. To make the most of what there is, the snail has a giant heart almost 4% of its total size. That's proportionally the largest heart in the animal kingdom.
Not weird enough yet? The snail doesn't actually "eat" anything. Most of its digestive system has atrophied, leaving a massively enlarged throat pouch - which the snail uses to "farm" chemosynthetic bacteria. These microbes turn the minerals being jetted out of hydrothermal vents into food, some of which the snail siphons off!
The bacteria also release sulfur, which can become toxic to the snail as it builds up. The scales of the snail actually leech the sulfur back out of the mollusk, where it combines with iron in the water to "plate" each scale in iron sulfite!
Picrophilus and Sulfolobus Archaea: Boiling Acid
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| Not a place to paddle... (NWimagesbySabrinaE) |
Would you want to live in a pool of boiling acid? Archaea from as the Picrophilus genus prefer the 60°C and PH of 0.7 waters of volcanic fumaroles and hot springs - conditions that a human would find themselves dissolving in!
You might be wondering how these microorganisms can stand such hostile conditions - their secret is a tough, positively charged and acid resistant cell wall, acting a bit like a hazmat suit!
The Sulfolobus genus of archaea can be found in similar conditions. Colonies in Yellowstone Park can actually oxidize sulfur from hot springs into sulfuric acid - this helps break rocks down into a muddy, chemical-rich slurry that the archaea can feed on!
The Sulfolobus genus of archaea can be found in similar conditions. Colonies in Yellowstone Park can actually oxidize sulfur from hot springs into sulfuric acid - this helps break rocks down into a muddy, chemical-rich slurry that the archaea can feed on!
Endoliths: Radioactive Rocks Three Kilometers Below the Surface
The idea of bacteria living in soil isn't new - but finding life in the darkness of a mine 3km beneath South Africa is a bit more novel.At first glance there's not much to recommend such a habitat - the rocks are a scorching 60°C, there's no natural light, the air pressure is around double that of sea level and the air must constantly be flushed to prevent a buildup of toxic gas.
Despite this, a community of microbes have been found living in tiny cracks within the stones, feeding on hydrogen released by water when it's "cracked" by ambient radiation. It's not an easy life though, and researchers theorize that they microbes have a very slow reproduction rate - possibly over a century between generations.
These extreme conditions could also be found on meteorites or even other planets... perhaps a similar form of alien life exists within our solar system, buried in stone and waiting to be found?
Tardigrades: Almost Anywhere There's Water on Earth... and Beyond?
These tiny aquatic animals are tough - so tough that they can be found almost anywhere on Earth where there's water, from the top of the Himalayan mountains to over 4.5km below the ocean.
The tardigrades big survival trick is to desiccate itself if desperate, removing 95% of the water from their bodies and entering a form of biological stasis. During this state (which can last for decades) their cells are coated in a shell of protein that prevents damage - they can survive the radiation of low Earth orbit, high and low temperatures, dehydration and starvation.
It's also possible that they remain alive and in stasis on the moon, as an Israeli spacecraft carrying dehydrated tardigrades crashed onto the lunar surface in 2019!
The tardigrades big survival trick is to desiccate itself if desperate, removing 95% of the water from their bodies and entering a form of biological stasis. During this state (which can last for decades) their cells are coated in a shell of protein that prevents damage - they can survive the radiation of low Earth orbit, high and low temperatures, dehydration and starvation.
It's also possible that they remain alive and in stasis on the moon, as an Israeli spacecraft carrying dehydrated tardigrades crashed onto the lunar surface in 2019!
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| Some creatures defy the cold... (Makri27) |
Paradise Beneath the Antarctic Ice... or Life in Space?
Lake Whillans (despite being located 800 meters beneath the ice of Antarctica) plays host to thousands of different microbial organisms. These creatures have survived without sunlight for over 120,000 years, possibly as many as a million.
The lake itself is a 2 meter deep disc that covers over 60 square kilometers. It also sits at slope, squashed and held in place by the ice pushing down on it.
Since it is effectively "sealed" from above, researchers believe that the creatures of the lake survive by breaking down minerals (like ammonia) trapped in the sediment... though there is the possibility that hydrothermal or methane vents could exist somewhere in the subglacial lake. If life can exist in such extreme conditions on Earth, could they do so elsewhere in our solar system?
Orbiting Jupiter, the icy moon Ganymede boasts a both magnetic field and water vapor evaporating into the limited atmosphere - it also features a subsurface liquid water ocean. There's also Titan, a moon that orbits Saturn. Like Ganymede the surface temperature is horribly cold, but the liquid-methane lakes and seas it bears could offer refuge to microorganisms like those found Lake Whillans!
Since it is effectively "sealed" from above, researchers believe that the creatures of the lake survive by breaking down minerals (like ammonia) trapped in the sediment... though there is the possibility that hydrothermal or methane vents could exist somewhere in the subglacial lake. If life can exist in such extreme conditions on Earth, could they do so elsewhere in our solar system?
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