Platypus is a rare egg-born mammal, with duck-like flippers and mouths, a flat tail like beaver , and a body like mole . No wonder scientists were amazed when they saw the pedals: "This is an animal that is pieced together with corners."
But such cute animals have plummeted due to crises such as climate change and human dams, and have become "invasive" species.
Cute platypus, how magical?
First, egg-born mammals that can place orders and produce milk
Platypus lives in the Australian continent and appeared on the earth as early as 25 million years ago. It is the only species in the Platypus family.
Platypus lay eggs like birds. After hatching platypus, they feed their pups like mammals. After years of controversy, scientists finally determined that platypus belonged to egg-born mammals and is the most primitive mammal that has not completely evolved.
Platypus is a monoporous species, and the rectum, urinary and reproductive organs are all connected to the same total excretion port.
. It has no breasts and nipples, but can breastfeed
Platypus has many different characteristics from other mammals. They did not evolve breasts and nipples. Until the 1830s, scientists discovered its breast .
Because there are no nipples, and the platypus beak does not have sucking action, their milk can only be discharged like sweat, seeping out from the pores on the skin of the abdomen, and then gathering into the depression on the platypus' belly through the fur, and the platypus obediently lay on their mother's belly and licking the milk.
has milk and eggs, and a platypus can make egg tarts by itself. It's really amazing.
rd, there are 5 pairs of independent chromosomes in the cells of the platypus. They aggregate together when the cells divide and determine the gender of the individual platypus.
The female with 10 X chromosomes is a female, the male with 5 X chromosomes and 5 Y chromosomes is a male, So in theory, the platypus may have 25 different genders, but this phenomenon has not happened in reality.
. For mating, male platypus are poisonous on their feet
platypus are called "architectural masters". Their nests are basically built by rivers and lakes. Through strong forelimbs, caves can be dug 15-20 meters deep. Even if there are small stones, they rarely get injured.
Because the webs of the platypus shrink like the claws of the tiger. When they are on the shore, they will shrink the webs into the soles of the feet, revealing their sharp claws.
A stinger grew on the hind leg of a male platypus. The stinger consists of a mixture of various toxic proteins. It can not only sting, but also spray out the venom like a venomous snake. The female platypus also had stingers when they were born, but it disappeared when they grew to a certain length.
Their toxicity can kill more than 20 kilograms of animals. Although its venom is not fatal to humans, it can temporarily lose the ability to move, the wounds are swollen and cause severe pain, and this severe pain will last for more than ten days or even several months.
The venom of male platypus is not used for hunting, but for territory or spouse. For mating rights, they will release venom to similar male platypus, attack their opponents, and finally obtain mating rights, so their venom will only be produced during mating season.
Fifth, the beak has a current sensor
platypus beak is covered with neurons. When they dive to prey, their eyes, ears, and nostrils are all closed. When the prey emits radio waves , the nerve endings on the beak can receive a weak biological current, and the platypus can accurately locate it, so as to quickly catch the prey.
There are two sensory organs on the beak of the platypus. One is the organ that senses electricity. The beak can sense electricity in about 40,000 receptors, and you can feel the faint electricity emitted by animals when they move.
Another type is the tactile organ. It is generally believed that there are about 60,000 tactile receptors. Even if you close your eyes, you can accurately locate food, and grab each other accurately.
Relying on this tactile organ, the platypus can also sense subtle water flow. The platypus uses different sensory organs to sense the weak current and water flow of prey, and then calculate the distance between it and prey based on the time difference.
And platypus love to eat everything, such as frogs, earthworms, , insects, etc., with an amazing appetite. A platypus with less than 2 pounds can eat foods that are comparable to their weight in a day.
After catching the prey, the platypus will not eat the prey immediately, but will first store it in a "small sac" on the cheek. Therefore, when they hunt, they move smoothly and slowly deal with the prey after the hunting is over.
Because the platypus has a beak, it cannot chew. The young platypus have teeth, but they all fall off after adulthood. They can only grind food through the keratin plate, just like those elderly people with dentures eating meat, slowly grinding and swallowing.
If you encounter food that is difficult to grind, the platypus will swallow some small stones and use small stones to help crush the food and promote digestion, because the platypus has no stomach.
Many netizens put the mouth of the platypus on other animals, but there was no sense of incongruity, and it felt just as cute.
, the fur will emit fluorescent
Under ultraviolet rays, the fur of the platypus can even emit fluorescent , because this feature causes them to kill themselves. As long as the fur of the animal is beautiful, their ending will be very tragic.
Why did such a cute platypus suddenly become a " near-dangerous " species
Since Europeans settled in Australia two centuries ago, the number of many animals has declined. For example, in 1888, in order to vigorously develop animal husbandry, a large number of Australian thyrofoams were killed. On December 7, 1936, the last thyrofoam died at the Hobart Zoo, and the species officially became extinct.
Australia's platypus were also injured, with the number of platypus falling by 50%.
There are many reasons for the decline of platypus in the beginning
. At first, some Europeans hunted animals for fur needs, just like the British and Dutch colonists in Africa, in order to obtain quaggar fur, they hunted quaggars until extinction.
. With the changes in climate, more and more frequent extreme weather such as droughts, fires, etc. directly threaten the survival of platypus.
kangaroo , the proliferation of hares, and the development of Australia have led to the continuous reduction of platypus habitat, as well as other invasive species predation and mishaps being caught by fishermen, making them in danger.
On the International Union for Conservation of Nature red list, platypus is listed as a "nearly dangerous" animal.
A recent study published in Communications-Bio shows that dams built in Australia seriously affect the survival of platypus.
Why does the dam affect the survival of platypus?
The impact of the dam on platypus is not at the individual level, but on the movement of the group, thereby affecting the survival of the integrated group.
Platypus and ducks have similar flippers, and in the absence of a dam, they can use flippers to move freely between rivers and rivers.
Platypus' clumsy flippers can cross a ten-meter-high river bank, but the height of the dam built in Australia is far more than 10 meters. Whether these poodles can climb over has always been a mystery.
To understand this puzzle, scientists selected 9 Australian rivers, extracted the DNA of 274 platypus near them, and processed and compared the gene composition of platypus upstream and downstream of each river.
If the platypus can move freely, the upstream and downstream racial genes can flow and exchange through mating, and there will be no difference in the gene composition.
On the contrary, if they cannot move freely, the upstream and downstream platypus can only reproduce internally and the genes cannot flow freely. Over time, some gene mutations will accumulate in a single group, eventually causing obvious genetic differences in the upstream and downstream platypus races.
Research results show that in the absence of a dam, the genes of platypus in the upstream and downstream distribution are not very different, but if there is a dam, their genes are 4 to 20 times that of the former, which proves that the dam will indeed prevent the movement of platypus and also affect the genetic composition of different populations.
, the blockade of gene communication, does not seem to directly endanger the life of platypus, and will lead to a decrease in the number of platypus in the future.
Platypus are blocked by the dam, and inbreeding increases
When more and more dams are built in Australia, platypus cannot move freely, and they will develop inbreeding. When inbreeding, the genomes of both parents are similar, and some recessive traits may appear in offspring.
For example, the parents of platypus have some genetic disease. When they resemble close to reproduction, the adaptability of offspring to the environment will decrease, and the number will naturally decrease. The genes of
form a single population. When facing catastrophic events, because their resistance is very poor, a disaster may cause them to exterminate.
If the genetic composition within the race is complex and diverse, when disaster occurs, some individuals within the platypus race may survive due to their unique traits, allowing the entire population to continue.
On the African savanna, male cubs of elephants and lions are driven out of elephant herds and lions after they become adults. It is not because their parents are cruel, but to prevent inbreeding.
If elephants and lions are inbreeding, more and more genetic diseases will occur, and eventually the number of animals will decrease and even become extinct.
Dam will also affect platypus to find new habitats
In the absence of a dam, if the environment becomes uninhabitable, platypus can freely migrate along the river to new places, but the emergence of dams restricts such migration and exacerbates the threat of natural disasters to platypus.
This situation is similar to the "habitat fragmentation" faced by many endangered species. The dams cut off the habitat of platypus and cut off other animals' homes.
may be a road, railway, or artificial forest garden built by humans, which prevents species from genetic communication and cannot find a better habitat.
The situation of the platypus is very similar to that of the Yangtze River White Sturgeon
The sad song of the Yangtze River White Sturgeon: Living for 150 million years, but not being able to survive until the New Year of 2020.
White sturgeon is the "living fossil" of Yangtze River , with a heaviest reaching 1,800 kilograms. Such a big fish cannot escape the fate of extinction in the end.
The last time humans saw the Yangtze River sturgeon was in January 2003. At that time, the three-meter-long Yangtze River sturgeon crashed into the net of a fisherman in Nanxi County, Yichang, Sichuan Province. He dragged the boat into the middle of the river and almost overturned the fishing boat, with an 8-centimeter-long wound on his body.
Later, experts rescued the Yangtze River white sturgeon and performed wound suture surgery on it. They also marked it when releasing it, and tracked it in real time, but its information could not be traced later.
On December 23, 2019, Chinese scientists published a paper in the international academic journal "Overall Environmental Science". The Yangtze River White Sturgeon, one of the largest freshwater fish on the earth, has become extinct in China's endemic species. It was only officially announced this year.
There are many factors that have been extinct in the Yangtze River paddlefish. In 1993, the Yangtze River paddlefish showed functional extinction. Functional extinction refers to the fact that it basically lost the function of maintaining reproduction under the natural environment, no reproductive ability, and naturally no offspring, and it is extremely difficult for species to continue.
As there are more and more dams in the Yangtze River, the Yangtze River sturgeon and the dam collided and died, because the Yangtze River sturgeon is a migratory fish. At the beginning of spring every year, it is the breeding period for adult Yangtze River sturgeons. At this time, they will leave their usual deep water areas and go upstream to the upstream Jinsha River to lay eggs.
After laying eggs, some of them returned to the downstream to fatten, some of them stayed upstream to continue their lives, and the hatched white sturgeon went downstream to find food.
In the 1980s, the Yangtze River blocking dam blocked the migration channels that the Yangtze River sturgeon have traveled through generations, isolated the upstream and downstream Yangtze River sturgeon. Migration has become a luxury for the Yangtze River sturgeon.
Moreover, after the dam is stored in water, the underwater environment changes to a certain extent, which has an impact on the egg laying and fattening of the Yangtze River white sturgeon.
The shipping and freight volume of the Yangtze River main line has been the world's largest for 10 consecutive years, but it has also brought huge damage to the water quality of the Yangtze River. Sand mining and sewage discharge along the Yangtze River are also relatively serious, and water pollution is serious.
The habitat of the Yangtze River paddlefish has been destroyed. They want to change to a suitable habitat, but after the dam is built, they cannot escape this cage, so some Yangtze River paddlefish have crashed to death on the dam.
Write to the end: If the Australian government does not take better protection measures for platypus, then the outcome of platypus may be the same as the Yangtze River paddlefish, and will eventually become: a "living fossil" that has lived for 25 million years, but cannot survive the 2040 Spring Festival.
