The adult platypus is 40-50 cm long, the female weight is between 700- 1600g, and the male weight is between1000-2400 g.
Platypus lives on the banks of rivers and streams. It spends most of its time in the water. Its fur is oily and can keep its body warm in cold water. When swimming in the water, it closes its eyes and looks for food at the bottom of the river bed by means of electrical signals and tactile sensitive duckbill. It feeds on mollusks and small fish and shrimp.
The platypus breeds in a long tunnel dug on its shore. She can lay up to three eggs at a time. After six months, the platypus will learn to live independently and feed at the bottom of the river bed.
In Australia, there is a strange mammal-platypus. It is strange because there is really no animal on earth that looks more like a platypus, and no animal has caused countless academic disputes like a platypus.
More than a hundred years ago, scientists didn't believe in the existence of platypus because it looked really strange, like reptiles, mammals and birds. The platypus often comes out of the hole by the river at dawn or dusk. Its flat mouth looks like a duck's mouth. But the difference is that the platypus's mouth has nerves that transmit touch, can bend and is sensitive to vibration, unlike birds' beaks with hard horniness. Its bright little eyes are held high above its head, so it can clearly see the river bank and scan the sky. The two grooves connecting the eyes and extending backward are its ears. The platypus has no ear shell, which can help it adapt to life in water. The fat body of platypus is covered with a layer of brown glossy dense hair, which will not be permeable when entering the water and will not be wet when leaving the water. Its big tail at the back of its body is flat and powerful, which acts as a rudder and can help it dive quickly. The platypus has short and thick limbs and webbed toes, especially webbed forelimbs. On land, it meets the webbed. And once it enters the water, it will open thick webbed, like several big paddles. Male platypus's hind legs also have a curved poison distance, which is similar to the fangs of poisonous snakes and has deadly venom.
When platypus preys, it usually closes its eyes, quickly dives into the river, rubs mud forward and relies on its keen mouth to find food. After about a minute or two, its cheeks will be full of food. At this time, the platypus will surface, open its eyes and enjoy the delicious food greedily. It likes shrimp, earthworms, insect larvae and mollusks. The platypus eats a lot, eating at least 1200 earthworms and more than 50 crayfish every day.
Another reason why platypus is strange is that although it belongs to mammals, it lays eggs with reptiles. It takes more than ten days for the eggs of platypus to hatch, and the young are born. At first, the cubs don't eat, but after a few days, the mother platypus will feed the cubs with her own milk. From the perspective of spawning, it is not difficult to know that platypus is quite primitive as a mammal.
In fact, the ancestors of platypus appeared as early as1.800 million years ago in Jurassic, when they were widely distributed. But by 70 million years ago, many advanced mammals had multiplied in large numbers, and these ancient animals were gradually extinct. But animals living in the Australian mainland are very lucky. Australia is separated from other continents due to crustal movement. So later mammals couldn't reach this place. The ancestors of platypus can live and reproduce here, maintaining the original spawning state. It plays an important role in studying the origin of mammals.