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How did the first animals get food? Where did the food come from, when there was no sunshine on the earth yet? How can food be produced on other planets with little or no sunshine? The answer to all these questions is complex, but it may be related to one animal, Alvinella – one of the most intriguing creatures of the deep sea. This essay will explore what Alvinella is, why it is so interesting and how it can help us understand our past, and maybe even our future.
Alvinella (Alvinella pompejana), the Pompeii worm, is a marine mollusk. It is thirteen centimeters (five inches) long, and pale gray in color. The Pompeii worm pokes its feather-like head out of its tube home to feed and breathe. The tentacle-like structures on the head are gills. Thanks to these gills, Alvinella can breathe at great depths. Its Latin name comes from two things. First, Alvinella comes from the submersible that discovered it, called “Alvin.” The second part of the name comes from the Roman city of Pompeii, which was covered by lava and ashes after a huge volcanic eruption, similar to how Alvinella’ s body is covered by mineral deposits.
The Pompeii worm only lives in the deepest part of the ocean, the Marianna Trench 1, located on the floor of the eastern Pacific Ocean. Where Alvinella lives, it is 2600 meters below the surface of the water. It is very dark there, and there are lots of toxic chemicals, for example sulfuric acid and high levels of arsenic and cadmium. It lives next to the gaps in the crust of the earth where hot gases escape. These gaps are called “hydrothermal vents”, and they give out enormous heat. The hottest of these vents are called “black smokers” because black hot gases come out from them. The black smokers form when mineral water, as hot as 350 degrees Celsius, flows out from a volcanic eruption onto the ocean floor. Minerals crystallize from the hot water onto the volcanic rocks and form chimney-like structures. Alvinella lives in delicate, thin tubes on the side of these vents where the temperature is 80° C (176° F), nearly hot enough to boil water. Of all animals on earth, Alvinella can stand the most heat.
How this worm can stand the extreme heat remains a mystery. On Alvinella’s back, there is a hairy coating of bacteria, up to a centimeter (0.39 inches) thick, which somehow enables it to live in the heat. Dr. Craig Cary, a marine biologist who was on the team that discovered Alvinella, believes that these bacteria contain special chemicals known as “eurythermal enzymes2 ” which can survive at very high temperatures. The bacteria feed on mucus secreted by glands on the worms' back (kind of like a firefighter's heat blanket, as Dr. Cary says). These bacteria also allow Alvinella to perform chemosynthesis, the creation of energy from chemicals rather than from sunlight.
Hydrothermal vents were first discovered in the 1980’s by some French explorers. In 1997, nearly 21 years after this discovery, Dr. Craig Cary and his colleagues3 wanted to learn more about hydrothermal vents, and dived in a submersible called “Alvin” to the depths of the Marianna Trench. Alvin is 7.5 meters (25 feet) long and can dive to a depth of 4 kilometers (2.5 miles). A pilot and two observers ride inside Alvin’s passenger compartment-a metal sphere that is 2 meters (7 feet) in diameter. The outside shell of the sphere is made of titanium, one of the strongest metals in the world. The scientists who were in Alvin discovered a mollusk and named it Alvinella.
Dr Craig Cary and his colleagues wanted to learn more about this bizarre creature. They decided to learn how hot it was inside the tube that Alvinella rested in, so they inserted a thermometer inside Alvinella’s tube and found out that the temperature was at 80° C (176° F), almost boiling! When they brought 200 of them to the ship, all of them died because of the change in pressure. According to the scientists “they do not decompress4 well.” Dr. Cary, the chief scientist for the Extreme 2002 expedition, says the research team's main objective was to learn more about the Pompeii worm's incredible heat tolerance by studying its unique biology and the bacterial colony that lives right on its back.
Alvinella is a very important animal for several reasons. This ancient creature can help us understand the past. It may have lived at the start of the earth before the initial gases surrounding the earth cleared up and sunlight reached the ground. Scientists believe that these organisms may have started life on earth. Alvinella might have been one of our greatest ancestors!
Alvinella can help us improve our present lives. By learning more about the special “eurythermal enzymes” on Alvinella’s back, scientists can understand more about how organisms that survive in extreme temperatures and pressure conditions. These enzymes are useful in high-temperature applications such as processing food and drugs and making paper, detergents and fabrics as well as other products helpful to us. They can also help dislodge oil inside wells, convert cornstarch to sugar, and support a number of other industrial processes by speeding up chemical reactions.
Finally, Alvinella can also help us in the future. We may be able to learn how to make food or energy on other planets without sunlight. By learning more about how life exists in extreme conditions, we may be able to find life forms on other planets. We may be able to discover some major marine alien life forms!
In conclusion, Alvinella is a very important creature for the human race. It may be able to help us in many ways if we learn more about it. More generally, Alvinella teaches us that by keeping an open and questioning mind and exploring places on our planet where we at first would not think that life is possible, we can be surprised and learn new things that can help us improve our lives.