"Natural Science 4" is an interactive encyclopedia that includes scientific information in the understanding of fourth grade students, wonderfully illustrated and animated.
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* Chapter 1 Lesson 5 *
* Long-lived animals *
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While for some animals life lasts a day, three or a few months, others can even reach hundreds of years.
The longest living, but also the largest land mammal is the elephant. He can reach the age of 70 years. The Indian elephant weighs up to 5 tons, and the African elephant - up to 7 and a half tons, reaching 3-4 m in height. Even though they are so massive, elephants are peaceful and intelligent animals. The trunk serves as a "bucket" in which they can take up to 10 liters of water and as a "hand" with which they can lift anything - from a needle to a tree trunk. Elephants have been human helpers since ancient times in India and other Southeast Asian countries, where they are used for jobs that a crane, tractor or automobile would perform.
But is the elephant the longest living animal on Earth?
It is certainly outclassed by several other species!
By far, the first place in the ranking is occupied by the jellyfish Turritopsis dohrnii, also called the immortal jellyfish. It is the only known case of biologically immortal living things. This small jellyfish lives in the Mediterranean Sea and in the waters of Japan. When injured or exposed to stress, sick or old, she can revert to the premature stage. Predators don't get close to her because she has stinging tentacles that keep them at bay.
The second place in the list of the longest-lived animals is occupied by a clam. The Quahog clam lives for about 400 years, but a 507-year-old clam has also been found. It lives in the cold waters of the Atlantic Ocean, and researchers still have no explanation for the slow rate of aging of this edible clam. If you are curious to know its age, you need patience to count the rings on the shell.
Swimming through the waters of Greenland you might meet the longest living vertebrate on Earth. The Greenland shark can live 200 years, but a 400-year-old specimen has been found. What is his secret? Its slow growth rate of only one centimeter per year makes it reach maturity at barely 100 years. These sharks are hunted both for their meat and their hard skin from which boots are made, but also for their teeth from which the Norse make all kinds of household tools.
It is also here that the longest-lived and second-largest mammal on Earth lives: the bowhead whale, which can exceed 200 years of age. People found out that they can be so long-lived after they found a specimen that had a 100-year-old harpoon stuck in it.
After a year of gestation, the female gives birth to a single cub, which she feeds with milk for up to 12 months. It is 4-5 meters long at birth and weighs no more than 1000 kilograms. Being endangered, its hunting is prohibited by law.
When we talk about long-lived animals, we can't help but mention the Galapagos tortoise. It can weigh more than 400 kilograms, with a length of about 2 meters. In the wild it can live over 100 years, in captivity there are known cases of specimens over 170 years old.
What is the secret of a long life?