Platypuses, also known as the duck-billed platypus, are weird and unique animals. So much so that the first scientists to examine a specimen believed they were victims of a hoax.
Looking at the animal is like looking at a combination of a duck (bill and webbed feet), a beaver (tail), and otter (body and fur). When the animal was first encountered by Europeans in 1798 a pelt and sketch were sent back to Great Britain by Captain John Hunter, the second Governor of New South Wales and British scientists' initially thought it was a hoax. Examining a dried specimen, George Shaw, who first described the platypus in the Naturalist's Miscellany in 1799, stated it was impossible not to entertain doubts as to its genuine nature. Another scientist, Robert Knox, believed it might have been produced by Asian taxidermist. Somebody had sewn a duck's beak onto the body of a beaver-like animal. Shaw even took a pair of scissors to the dried skin to check for stitches. Early settlers called it by many names, such as "watermole", "duckbill", and "duckmole".
Until the early 20th century, it was hunted for its fur, but it is now
protected. Captive breeding programs have had only limited success and
in the wild the platypus is vulnerable to the effects of pollution.
Platypuses are unique because males are venomous. They have sharp stingers on the heels of their rear feet and can use them to deliver a strong toxic blow. The venom (most is secreted during mating season) is not life threatening to humans, but it is powerful enough to kill smaller animals such as dogs. The pain is so excruciating that the victim may be incapacitated. Swelling rapidly develops around the wound and gradually spreads throughout the affected limb. A byproduct of this is the development of hyperalgesia which is a heightened sensitivity to pain that persists for days or even months.
While the venom is used against predators if threatened (the platypus would actually rather run than fight), it is primarily used against other male platypuses during mating season. They fight to show dominance and scare away potential mating rivals. They have been heard to emit a low growl when disturbed and a range of other sounds have been reported in captive specimens.
They are indigenous to freshwater rivers and lakes in eastern Australia and Tasmania and are roughly the size of a house cat. They are covered in thick, dark brown hair over most their bodies. The thick hair is waterproof and helps keep the platypus keep warm and dry when in the water, where it spends most of its time.
Platypuses hunt underwater where they swim by paddling with their front webbed feet and steering with their hind feet and beaver-like tail. Folds of skin cover their eyes and ears to prevent water from entering and the nostrils close with a watertight seal. They can remain submerged for a minute or two and employ their sensitive bill to find food. The platypus needs to eat about 20 percent of its own weight each day which requires it to spend an average of 12 hours daily looking for food.
Bottom feeders, they scoop up insects, larvae, shellfish, and worms in their bill along with bits of gravel and mud and all this material is stored in cheek pouches. At the surface it's all mashed for consumption. Like the rest of the animal, their bills are unique, containing both electrical and pressure receptors. The platypus can determine the direction of an electric source, perhaps by comparing differences in signal strength across the electro-receptors. This would explain the characteristic side-to-side motion of the animal's head while hunting. The platypus uses the difference between arrival times of the signals to sense distance. When it digs with its bill, its electro-receptors detect tiny electric currents generated by muscular contractions of its prey, enabling it to distinguish between animate and inanimate objects which also stimulate its mechano-receptors.
The babies have a few teeth which they lose before or just after leaving the burrow and the develop pads in their place. These pads are used to crush and grind their food with help of small stones they have picked up along with their food. As one would expect, the platypus jaw is constructed differently from that of other mammals and the opening muscle is different.
The platypus has extra bones in the shoulder area which is not found in other mammals and their bones are extra dense which helps to provide ballast in the water. On land they walk like an alligator because their legs are on the sides of the body, rather than underneath. This causes it to knuckle-walk on its front feet. The nails and feet are also handy when they construct their burrows at the water's edge.
Platypuses are also unique in that they are only one of two mammals that lays eggs. Bet you don't know what the other one is. It's the echidna, also known as the spiny anteater.
Females seal themselves inside a burrow chamber to lay their lizard-like eggs, usually one or two, and keeps them warm by holding them between her body and her tail. The eggs hatch in about ten days and the babies are the size of Lima beans and totally helpless. Females nurse their young for three to four months until the babies can swim on their own. The males have nothing to do with the eggs or the blind and hairless newborns.
As you might expect, it also has eyes that are different. They are similar to those of Pacific hagfish or Northern Hemisphere lampreys. They also contain double cones, which most mammals do not have. Its eyes are small and not used under water. In some ways the eyes are similar to those of an otter and sea-lions. They have binocular vision, but poor visual acuity. Studies of their eyes indicate that they are adapted to an aquatic and nocturnal lifestyle although they are also active during the day, particularly when the sky is overcast.
In captivity, platypuses have survived up to 17 years. Natural predators include snakes, water rats, goannas, hawks, owls, and eagles and crocodiles.
I know you're dying to know if they are edible!
There are some foods that are banned in most restaurants either because they come from highly poisonous animals or it must be cooked exactly as specified if you want to avoid killing yourself. Of course this doesn’t some people from playing Russian Roulette.
For example, in certain Asian countries the Puffer Fish as an exquisite delicacy. Their meat is perfectly edible because the poison is concentrated in the eyes, skin and the internal organs. The problem is, one wrong move by the chef and you'll be in paralytic coma that will kill you within a few minutes. It only takes a few milligrams (one drop of water is about 50 milligrams) of their poison to kill a full grown man. The fish is so poisonous that in order to be allowed to prepare it in Japan you have to train for two to three years and then pass a test. What's the test? You have to eat the meat yourself.
Australia has a lot of weird animals, some of which are edible and some are not. They exported kangaroo meat as early as 1959, but it was not legalized for human consumption in most Australian states until 1993. I am told most Australian supermarkets carry various cuts of kangaroo – fillets, steaks, minced meat and sausages. So, it's quite edible.
Koala bears look cuddly and adorable, but they have razor-sharp claws and are highly unsociable animals. They are listed as vulnerable in the Australian Endangered Species List so you are not allowed to eat them. It is illegal to keep a Koala as a pet anywhere in the world.
Emus are farmed for their meat, oil and leather. Their meat is low in fat and high in protein and as such it's as a healthy alternative to beef. It's similar to beef, but more gamey.
Wombats are also on the protected list and it is illegal to kill them. Some species of wombat are even on the endangered list.
Quokka. These adorable macropods are much like a small kangaroo. It is illegal to even touch a quokka so they are not used as food.
The Kookaburra is a carnivorous bird known for eating their young. They are crafty birds, hard to catch and they are not eaten.
A dingo is a wild dog and is classified as a subspecies of the grey wolf and are listed as vulnerable to extinction due to interbreeding with domestic dogs. Dog meat is not generally considered edible, so nobody eats dingos.
That brings us to the Echidna (not edible) mentioned previously and platypuses. The platypus is poisonous so it's not edible. What about the eggs? They are only 11mm in diameter (less than half an inch) so it would take a lot of them to make a meal, but I was unable to find a source that even mentioned platypus eggs as a source of food for humans.