Extremophiles are organisms that are able to thrive under extreme conditions. Extremophiles can be found in environments of high or low temperature, high pressure, high salt or acidity, or low oxygen, among others. These extreme conditions would be harmful to most other life on earth. It is suggested that the ability to adapt to these conditions by the extremophiles may have been important to the development of early life. EXTREMOPHILES Water Bear

Common types of Extremophiles…

PSYCHROPHILES...an organism capable of growth and reproduction at temperatures of -15 °C or lower. They can be commonly found in permafrost, polar ice, and deep under snowpack. An example of a Psychrophile is the Ice Worm. When ice worms are exposed to temperatures 5 °C or higher, their body structures literally “disintegrate” and fall apart. They can be several centimeters long, and tunnel through the ice feeding on algae. Ice Worm

ACIDOPHILES...an organism that grows best at a low, or acidic pH level of 3 or less. Red and green algae can grow below a pH 1 and fungi can grow near a pH of 0. Red Algae

ALKALIPHILES...an organism that grows best at a high, or alkaline pH level of 9 or greater. They survive well in soils and lakes where the pH is high, because the can moderate their own pH level internally. They are also able to grow under normal conditions.

ENDOLITHS...an organism that lives in microscopic spaces within rocks, aquifers, or faults, often filled with water deep under the surface. Their main food source is CO2, but they also eat rocks.

THERMOPHILES...an organism that can thrive at very hot temperatures, ranging between 60– 80 °C. Thermophiles are found in various geothermally heated areas of the earth, such as hot springs like those in Yellowstone National Park. Hot spring

HYPERTHERMOPHILES...an organism that can thrive at extremely hot temperatures, ranging between 80–122 °C. They can often be found in hydrothermal systems (underground reservoirs). Then can also tolerate high acidity or radiation levels. Hot spring

HYPOLITHS...an organism that generally lives inside rocks in climatically extreme deserts. The rocks that host Hypoliths protect them from wind and radiation, and are generally translucent, allowing light to penetrate and moisture to accumulate. Translucent rock

PIEZOPHILES...an organism that thrives at high pressures. They are commonly found far below the earths surface on the ocean floor, and up to 6.5 miles in the deepest trenches.

RADIORESISTANTS...an organism resistant to high levels of radiation, including ultraviolet and nuclear radiation. They can often be found in toxic waste sites, and have been known to withstand 20,000 Gy (Greys) of gamma radiation.

XEROPHILES...an organism that can grow and reproduce in extremely dry conditions. They can reproduce requiring almost no water. Tardigrades are an example of an Xerophile. They are one of the few animals that con be found both on the highest mountains and the deepest seas. They are able to survive in environments that would kill almost all other creatures. For example, they can survive for a small number of days in outer space, they can tolerate temperatures close to absolute zero and the boiling point, and can live without water for close to ten years (although they spend most of their lives in water) They are considered to be earth’s toughest survivors. Water Bears