The platypus is a rare oviparous mammal, with duck-like flippers and mouths, a flat tail like a beaver, and a body like a mole, and scientists exclaim when they see a duck-footed animal: "This is an animal patchwork with corners."
But such cute animals, due to crises such as climate change and human dams, have plummeted in number and have become "endangered" species.
How amazing is the cute platypus?
First, oviparous mammals that can order and produce milk
The platypus is a species living on the Australian continent that appeared on Earth as early as 25 million years ago, and is the only surviving species of the platypus family.
The platypus lays eggs like birds, hatches the platypus, and feeds the cubs like mammals, and after years of controversy, scientists finally determined that platypus belongs to oviparous mammals, the most primitive mammals that have not fully evolved.
Second, you can breastfeed without breasts and nipples
The platypus had many characteristics that differed from other pre-existing mammals, and they did not evolve breasts and nipples until scientists discovered its mammary glands in the 1930s.
Because there are no nipples, and the platypus beak does not have the ability to suck, their milk can only be discharged like sweat, penetrating from the pores on the skin of the abdomen, and then collecting through the fur to the hollows on the platypus' stomach, and the platypus obediently lie on the mother's stomach and lick the milk.
Third, it has 10 chromosomes
There are 5 pairs of separate chromosomes in platypus cells, which clump together when the cell divides and determine the sex of individual platypus.
Females with 10 X chromosomes and males with 5 X chromosomes and 5 Y chromosomes,
Fourth, male platypus have poisonous feet in order to mate
Known as "master builders", platypus have nests built on rivers and lakes, and can dig burrows 15-20 meters deep by digging burrows with strong forelimbs, and even if there are small stones, there are few injuries.
Because the webbing of platypus contracts like the claws of a tiger, when they are on the shore, they will shrink the webbing into the soles of their feet, revealing sharp claws.
Their toxicity can kill more than 20 pounds of animals, although its venom is not fatal to people, but it will also temporarily incapacitate people, the wound is swollen and produces severe pain, and this severe pain will last for ten days or even months.
The venom of male platypus is not used for hunting, but for territory or mates, and for mating rights, they release venom on male platypus of the same kind, attack opponents, and finally win mating rights, so their venom is only produced during the mating season.
Fifth, the beak has a current inductor
The beak of the platypus is full of neurons, when they dive to hunt, the eyes, ears, nostrils are all closed, when the prey emits radio waves, the nerve endings on the beak can receive a weak biocurrent, the platypus can accurately position, so as to quickly catch the prey.
There are two sensory organs on the beak of platypus, one is the organ that senses electricity, and there are about 40,000 receptors on the beak that can sense electricity, and you can feel the weak electricity emitted by the animal when moving.
Relying on this tactile organ, the platypus can also sense the subtle flow of water, and the platypus uses different sensory organs of the beak to sense the weak current and water flow of the prey, and then measure the distance between it and the prey according to the time difference.
And platypus loves to eat everything, such as frogs, earthworms, insects, etc., the amount of food is amazing, a platypus of less than 2 pounds, can eat food equivalent to its own weight in a day.
Because platypus has a beak, it cannot perform chewing actions, juvenile platypus have teeth, but they all fall off when they are adults, and can only grind food through the cuticle plate, just like those old people with dentures eat meat, slowly grind and swallow.
If it encounters food that is difficult to grind, the platypus will swallow some small stones, and use the small stones to help crush the food and facilitate digestion, because the platypus does not have a stomach.
Sixth, the fur will glow
Under ultraviolet radiation, platypus' fur can even emit fluorescence, because of this feature, they attract the scourge of killing, as long as the animal's fur is good-looking, their end is tragic.
Why did such a cute platypus suddenly become a "near-threatened" species?
Since Europeans settled in Australia two centuries ago, many animal populations have declined, such as in 1888, a large number of Australian thylacines were killed in order to vigorously develop animal husbandry, and on December 7, 1936, the last thylacine died at Hobart Zoo, and the species was officially extinct.
There are many reasons for the initial decline of platypus
1. At first, some Europeans hunted animals for their fur, just like the British and Dutch colonists in Africa, in order to obtain the fur of the donkey, hunted the donkey to extinction.
2. With the change of climate, more and more frequent extreme weather such as drought, fire, etc., directly threaten the survival of platypus.
The proliferation of kangaroos and wild hares, and development in Australia has led to the decline of platypus habitat, as well as predation by other invasive species, and overcatch by fishermen, making them precarious.
On the IUCN Red List, platypus is listed as "near threatened".
A recent study published in Communic-Creatures showed that dams built in Australia seriously affect the survival of platypus.
Why do dams affect platypus survival?
The impact of the dam on the platypus is not at the individual level, but affects the movement of the group, and thus the survival of the integrated group.
Platypus and ducks have similar flippers, and in the absence of a dam, they can use their flippers to freely swim up and down rivers.
To solve the puzzle, scientists selected nine Australian rivers, extracted the DNA of 274 platypus near them, and compared the genetic composition of platypus upstream and downstream of each river.
If platypus can move freely, upstream and downstream race genes can flow and exchange through mating, and there will be no difference in genetic composition.
The results show that in the absence of a dam, there is no big difference in the genes of platypus distributed upstream and downstream, but if there is a dam, their genetic difference is 4~20 times that of the former, which proves that the dam will indeed prevent the movement of platypus and affect the genetic composition of different populations.
This 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 were stopped by dams and inbreeding increased
When more and more dams are built in Australia, platypus cannot move freely, they will inbreed, and when inbreeding occurs, the genomes of both parents are similar, and some recessive traits may appear in offspring.
For example, the parents of platypus have a certain genetic disease, and when they breed closely, the offspring will be less adaptable to the environment, and the number will naturally become less and less.
If the genetic composition within the race is complex and diverse, some individuals within the platypus race may survive due to their own unique traits and allow the entire population to continue.
In the African savannah, male cubs of elephants and lions are driven out when they reach adulthood, and herds of elephants and lions are not cruel to their parents, but to prevent inbreeding.
The dam also affects platypus in finding new habitat
In the absence of a dam, platypus can freely migrate along the river to new places if the environment becomes uninhabitable, but the emergence of dams limits such migration and exacerbates the threat of natural disasters to platypus.
The situation is similar to the "habitat fragmentation" that many endangered species face, with dams cutting off platypus habitat and other animal homes.
The situation of the platypus is very similar to that of the Yangtze paddlefish
The sad song of the Yangtze River paddlefish: It has lived for 150 million years, but has not survived to the New Year of 2020.
The white sturgeon is a "living fossil" of the Yangtze River, weighing up to 1800 pounds, and such a large fish cannot escape the fate of extinction.
The last time humans saw a paddlefish was in January 2003, when the three-meter-long paddlefish crashed into the net of a fisherman in Nanxi County, Yichang, Sichuan Province, dragged the boat into the center of the river, and almost overturned the fishing boat, leaving an 8-centimeter-long wound on its body.
On December 23, 2019, Chinese scientists published a paper in the international academic journal Holistic Environmental Science that one of the largest freshwater fish on Earth, the endemic species of the Yangtze paddlefish, has become extinct, and it was only officially announced this year.
There are many factors in the extinction of the Yangtze paddlefish, in 1993, the Yangtze paddlefish appeared functional extinction, functional extinction refers to the natural environment, basically lose the function of maintaining reproduction, no reproductive ability, nature has no offspring, species continuation is extremely difficult.
After spawning, some return downstream to fatten, some stay upstream to continue living, and hatched paddlefish go down the water in search of food.
In the 80s, the dam of the Yangtze River blocked the migration channel through which the Yangtze paddlefish had traveled for generations, isolating the upstream and downstream Yangtze paddlefish, and migration became a luxury for the Yangtze paddlefish.
The Yangtze River trunk line shipping volume has ranked first in the world for 10 consecutive years, but it has also brought great harm to the water quality of the Yangtze River, and sand mining and sewage discharge along the Yangtze River are also relatively serious, which seriously pollutes the water.
The habitat of the Yangtze paddlefish was destroyed, and they wanted to change to a suitable habitat, but after the dam was built, they could not escape this cage, so some Yangtze paddlefish crashed and died on the dam.
Write to the end: If the Australian government does not make better protection measures for platypus, then the fate of platypus, like the Yangtze River paddlefish, will eventually become: "living fossils" that have lived for 25 million years, but will not survive the Spring Festival in 2040.