If one day, we want to live in the ocean, would like to be what kind of animal? People are born with a hero complex, I believe many students want to be the biggest whale!
A whale is not a fish, but a Marine mammal. The ancestors of whales were mammals that lived on land. An asteroid impact 65 million years ago wiped out not only large reptiles like the dinosaurs on land, but also giant dinosaurs and lizards in the ocean. That leaves plenty of ecological niches open, both on land and in the sea. Some mammals returned to the sea, including whales about 50 million years ago.
On land, the largest animals were the extinct dinosaurs, limited by the mechanical capacity of their bones and muscles. In the ocean, the buoyancy of the water allows animals to break through the mechanical limitations of musculoskeletal structures, grow large and become heavy. The blue whale, for example, can reach 33 meters in length and weigh more than 180 tons, standing 11 stories high. The average cow weighs one ton, which translates to more than 180 adult scalpers.
Whales' terrestrial relatives are mammals of the order artiodactyl, because the ankle of a whale has a distinct double-pulley shape, similar to that of artiodactyl mammals. Among artiodactylates, whales and hippos are the most closely related, but less related to pigs, camels, and ruminants such as cattle and sheep.
The ancestors of whales may have been ungulates, mesonychids, a group of extinct primitive mammals that flourished during the Eocene epoch, about 45m years ago. Mesonychids do not have claws, but have tiny hoofs on their toes, and may be the ancestors of artiodactyls.
Whales are now divided into baleen whales and toothed whales. Dolphins are also small or medium-sized toothed whales. Baleen whales "talk" by infrasound, toothed whales "chat" by ultrasound. Students have learned a lot about these from TV and newspapers. Today, we're going to focus on what happens after whales die.
Whale carcasses, dangerous ticking time bombs
Normally, whales are born in the sea, raised in the sea and died in the sea. However, news of whales stranding on beaches has not been uncommon in recent years. Whales rely on infrasound or ultrasonic waves to communicate, feed and navigate. Sonar from ships and submarines can interfere with the whales' judgment, causing them to mistakenly hit the beach. Once stranded, it is difficult for a whale to get out of its predicament and return to the ocean through its own efforts.
The whale carcass on the beach is a dangerous time bomb. After a whale dies, microbes continue to digest and ferment the food in its digestive tract, producing large amounts of explosive gases such as methane, hydrogen sulfide and ammonia. Meanwhile, when whales die, their tissues and organs decay at an accelerated rate, producing explosive gases such as methane, hydrogen sulfide and ammonia. In this way, the gas accumulates in the body and the pressure of the gas increases. Some fragile skin parts can not bear such pressure, just like being opened pressure cooker valve, the gas in the body like a volcano erupts out, high-speed airflow to the surrounding air for rapid and violent compression, its effect is like a bomb explosion.
So keep a safe distance from dead whales.
The whale falls, the most beautiful rebirth on earth
Normally, a whale is surrounded by water while alive and returns to the sea after death. Since the whale's body is slightly denser than the water, its carcasses slowly and solemnly sink hundreds or even thousands of meters into the ocean floor, forming a whale colony that continues to nourish and shelter a wide variety of Marine life and even serve as a home for coral polyps, eventually forming a reef based on the whale skeleton.
As the carcass descends, hagfish, sharks, porpoise and other scavengers gather to feast on the dead whale's organs and tissues. Weighing as much as more than 180 cattle, adult blue whales are enough to feed the hungry insects for a few months, or even a year or two.
Whales that have fallen to the sea floor continue to feed scavengers in their flesh. Finally, all that was left of what was once the giant of the ocean was a craggy skeleton. This is when the "foodies", who are used to eating large chunks of meat, leave. The boners are here. They're crustaceans, invertebrates. They patiently and meticulously search for fragments of tissue that have fallen to the sea floor and hidden between bones until the whale skeleton is stripped as clean as a specimen in a natural history museum. This process can take months, even years. One of them, called a bone-eating worm, acts like a tiny tree and attacks whale bones. They stick branching tentacles like "roots" into the whale's bones, soaking up nutrients.
Nature's shrewdness and stinginess lie in the extreme value of organic matter. Whale bones are fertilized by anaerobic bacteria. These anaerobic bacteria invade the whale's bones and break down fat and organic matter, producing large amounts of hydrogen sulfide. The gas, which smells like rotten eggs and is a nuisance in our daily lives, is a valuable source of energy for chemoautotrophic bacteria. They use it as "gasoline" to drive the synthesis of organic compounds such as proteins, polysaccharides and fats, which in turn feed a host of microscopic Marine organisms and a host of lower Marine organisms such as seashells. Then, the big fish eat the little fish, and the little fish eat the shrimp, and the dead whales feed back up the food chain to their children and grandchildren and help rebuild the ocean.
Now, whatever whales can eat becomes part of the body of a wide variety of creatures. The remains of the skeleton began to form reefs on the seafloor, on which polyps slowly gathered. A new reef begins to form, like a whale's rebirth.
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