+Mirumir Subscriber¹ Posted April 21, 2011 Subscriber¹ Share Posted April 21, 2011 Hello, everyone! I'd like to present to you one of the most unique species on our planet! Tardigrades (commonly known as water bears or moss piglets) form the phylum Tardigrada, part of the superphylum Ecdysozoa. They are microscopic, water-dwelling, segmented animals with eight legs. Tardigrades were first described by Johann August Ephraim Goeze in 1773 (kleiner Wasserb?r = little water bear). The name Tardigrada means "slow walker" and was given by Lazzaro Spallanzani in 1777. The name water bear comes from the way they walk, reminiscent of a bear's gait. The biggest adults may reach a body length of 1.5 millimetres (0.059 in), the smallest below 0.1 mm. Freshly hatched larvae may be smaller than 0.05 mm. More than 1,000 species of tardigrades have been described. Tardigrades occur over the entire world, from the high Himalayas (above 6,000 metres (20,000 ft)), to the deep sea (below 4,000 metres (13,000 ft)) and from the polar regions to the equator. The most convenient place to find tardigrades is on lichens and mosses. Other environments are dunes, beaches, soil, and marine or freshwater sediments, where they may occur quite frequently (up to 25,000 animals per litre). Tardigrades often can be found by soaking a piece of moss in spring water. Tardigrades are able to survive in extreme environments that would kill almost any other animal. Some can survive temperatures of ?273 ?C (?459 ?F), close to absolute zero, temperatures as high as 151 ?C (304 ?F), 1,000 times more radiation than other animals, and almost a decade without water. In September 2007, tardigrades were taken into low Earth orbit on the FOTON-M3 mission and for 10 days were exposed to the vacuum of space. After they were returned to Earth, it was discovered that many of them survived and laid eggs that hatched normally. Physiology Tardigrades are one of the few groups of species that are capable of reversibly suspending their metabolism and going into a state of cryptobiosis. Several species regularly survive in a dehydrated state for nearly ten years. Depending on the environment they may enter this state via anhydrobiosis, cryobiosis, osmobiosis or anoxybiosis. While in this state their metabolism lowers to less than 0.01% of normal and their water content can drop to 1% of normal. Their ability to remain desiccated for such a long period is largely dependent on the high levels of the non-reducing sugar trehalose, which protects their membranes. In this cryptobiotic state the tardigrade is known as a tun. Tardigrades have been known to withstand the following extremes while in this state: * Temperature ? tardigrades can survive being heated for a few minutes to 151 ?C (424 K)!, or being chilled for days at -200 ?C (73 K)!, or for a few minutes at -272 ?C! (~1 degree above absolute zero). * Pressure ? they can withstand the extremely low pressure of a vacuum! and also very high pressures!, more than 1,200 times atmospheric pressure!. It has recently been demonstrated that tardigrades can survive the vacuum of open space and solar radiation combined for at least 10 days!. Recent research has revealed that they can also withstand pressure of 6,000 atmospheres!, which is nearly six times the pressure of water in the deepest ocean trench. * Dehydration ? tardigrades have been shown to survive nearly 10 years! in a dry state. When encountered by extremely low temperatures, their body composition goes from 85% water to only 3%. As water expands upon freezing, dehydration ensures the tardigrades do not get ripped apart by the freezing ice (as waterless tissues cannot freeze). * Radiation ? tardigrades can withstand median lethal doses of 5,000 Gy (of gamma-rays) and 6,200 Gy (of heavy ions) in hydrated animals (5 to 10 Gy could be fatal to a human). The only explanation thus far for this ability is that their lowered water state provides fewer reactants for the ionizing radiation. In September 2007, a space launch (Foton-M3) showed that tardigrades can survive the extreme environment of outer space for 10 days!. After being rehydrated back on Earth, over 68% of the subjects protected from high-energy UV radiation survived and many of these produced viable embryos, and a handful survived full exposure to solar radiation. Reminds of the Aliens in the movie :laugh: Ash: You still don't understand what you're dealing with, do you? The perfect organism. Its structural perfection is matched only by its hostility. Lambert: You admire it. Ash: I admire its purity. A survivor ? unclouded by conscience, remorse, or delusions of morality. Maybe one day in billions of years these guys evolve into nasty predators :rofl: Link to comment Share on other sites More sharing options...
Teebor Posted April 21, 2011 Share Posted April 21, 2011 It looks like the bag from inside my hoover Amazing little critter though Link to comment Share on other sites More sharing options...
LOC Veteran Posted April 21, 2011 Veteran Share Posted April 21, 2011 Wow, exposed to the vacuum of space and survived. That's amazing. Also, they look like an anus mixed with a hoover vacuum to be honest.... Link to comment Share on other sites More sharing options...
vincent Posted April 21, 2011 Share Posted April 21, 2011 Images are t3h broke Link to comment Share on other sites More sharing options...
+Mirumir Subscriber¹ Posted April 21, 2011 Author Subscriber¹ Share Posted April 21, 2011 Wow, exposed to the vacuum of space and survived. That's amazing. Also, they look like an anus mixed with a hoover vacuum to be honest.... haha Images are t3h broke Thanks! I've fixed it! A couple of new pix have been added! Link to comment Share on other sites More sharing options...
Lezard Posted April 21, 2011 Share Posted April 21, 2011 Wow, so fricking AMAZING. :woot: :woot: :woot: :woot: :woot: :woot: :woot: :woot: I wonder if we can drop some in mars and then check to see if they survived/formed their own eco system.. Link to comment Share on other sites More sharing options...
Growled Member Posted April 22, 2011 Member Share Posted April 22, 2011 Looks like a tacky creature from either Doctor Who or Star Trek. Amazing stuff, though. Link to comment Share on other sites More sharing options...
+Mirumir Subscriber¹ Posted April 22, 2011 Author Subscriber¹ Share Posted April 22, 2011 Wow, so fricking AMAZING. :woot: :woot: :woot: :woot: :woot: :woot: :woot: :woot: I wonder if we can drop some in mars and then check to see if they survived/formed their own eco system.. haha :laugh: or expose them to some drug or hormones that would make them move faster and clean the radiation in Japan! Link to comment Share on other sites More sharing options...
.thumb.png.32b40aac36b342b70aeb7f6159cb5919.png)
Recommended Posts