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[[File:14528515709033 546x0.jpg|thumb]] | [[File:14528515709033 546x0.jpg|thumb]] | ||
'''Tardigrades''' are microscopic animals | '''Tardigrades''' are invertebrate microscopic animals popularly known as '''water bears'''. These organisms measure between 0.3 mm and 0.5 mm, although some can reach up to 1 mm. They are characterised by a cylindrical body, segmented into four pairs of legs with claws at the ends. | ||
This is made possible by their ability to shut down their organs when environmental conditions are not suitable ( | Their body is covered by an external cuticle, which they shed periodically. They are bilaterally symmetrical and have a complete digestive system, but lack a respiratory and circulatory system. Instead, they obtain oxygen by diffusion through their skin. They are aquatic animals and live in humid enviromets such as '''mosses''', lichens, wet soils and even in seawater and freshwater, where they feed on plant cells or small invertebrates.[[File:Istockphoto-1295483613-612x612.jpg|thumb]]They have become truly remarkable for their '''high resistance''' to extreme environments such as freezing at temperatures close to absolute zero, high temperatures up to 150°C, extreme dehydration, starvation for decades, high levels of radiation and space vacuum, extreme pressures, both high and low... This is made possible by their ability to shut down their organs and stop their metabolism when environmental conditions are not suitable (this is called '''cryptobiosis''') and come back to life when optimal conditions are restored. | ||
One of the reasons these organisms are so resilient is because of a protein that only they produce. These abundant heat-soluble cytoplasmic proteins (CAHS) cause the inside of the cells to turn into a gel, which prevents the cell from collapsing. [[File:Tardigradee.png|thumb|tardigrades in the laboratory]]The '''reproduction''' is mainly sexual, although in some species asexual reproduction by parthenogenesis is observed. Females lay their eggs during cuticle shedding, and fertilisation occurs within the cuticle, or in the external environment in some species. | |||
The study of tardigrades has attracted great interest due to their extraordinary resilience, which could have applications in '''biomedicine''', '''astrobiology''' and '''tissue preservation technologies'''. They are also used as '''biomarkers''' to study the impact of climate change and pollution in extremophile environments. | |||
At the begining they where looking full of food but after a month in this contaminated*(you don't say contaminated, it's just a sample) sample we found most of the tardigrades went to sleep mode probably due to lack of food. | '''In the laboratory''', we could take care of some of them. First we disolve the initial sample which had a huge amount of tardigrades and as food they had algae. Then some of them were "sacrifice" as a contaminated sample so we could observe them through the microscope. [[File:In the lab.png|thumb|disolving the sample]]At the begining they where looking full of food but after a month in this contaminated*(you don't say contaminated, it's just a sample) sample we found most of the tardigrades went to sleep mode probably due to lack of food. | ||
Alessandro's input: | Alessandro's input: | ||