Tardigrades are phylum eight-legged segmented micro-animals. These species have been sent to space by Japan ‘s National Institute of Polar Research. There are about 1,300 known species in the phylum- Tardigrada, a part of the superphylum is Ecdysozoa consisting of animals that grow by ecdysis such as arthropods and nematodes. The earliest known true members of the group are known from Cretaceous (145 to 66 million years ago) amber, found in North America, but are essentially modern forms, and therefore likely have a significantly earlier origin, as they diverged from their closest relatives in the Cambrian, over 500 million years ago. They are often found on lichens and mosses and can be seen by soaking a piece of moss in water. These species are not harmful to humans. They can survive extreme conditions by going into a “tun” state, in which their body dries out and their metabolism drops to as little as 0.01 percent of its normal rate. When conditions return to normal, the tardigrade revives itself. A tardigrade can stay in a tun state for decades. Scientists of Japan’s National Institute of Polar Research have brought a frozen animal back ‘Tardigrade ‘which they had collected in Antarctica 30 years ago.
They are commonly known as ‘water bears’, or ‘moss piglets’. Tardigrades are usually about 0.5 mm (0.02 in) long when fully grown. They are short and plump, with four pairs of legs, each ending in claws (usually four to eight) or suction disks. They feed on plant cells and algae. They can survive years without food or water, withstand freezing and scalding temperatures and endure blistering radiation and the vacuum of outer space.
Tardigrades are very tough animals and are found everywhere on earth, from mountain tops to deep seas. They have survived five mass extinctions. Recently, Nasa had sent 5,000 tardigrades into space. Tardigrades have been sent because of their ability to survive under high-stress environments.
Credits: Jothika
Very interesting
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