Platypus

A platypus is one of the most unique species of the animal kingdom. This amphibious, egg-laying mammal is scientifically named Ornithorhynchus anatinus. Platypuses have a flat bill and webbed feet like that of ducks; a beaver-like paddle-shaped tail; and a sleek body with fur similar to an otter. Along with the light and dark brown fur on the body, they have white, furry patches under their eyes which add to their distinctive appearance. The features of the duck-billed platypus are adapted for its semi-aquatic nature. They have a flattened body and streamlined head with dense waterproof fur which helps in swimming and strong limbs which helps them in digging. Due to small eyes, when platypuses are submerged in water, their sense of sight, hearing, and smell tend to shut down, but they have unique touch receptors and electroreceptors which is an electromechanical system that helps in navigation underwater. Similar electroreceptors are also found in echidnas, the other mammals of order Monotremata.

Origin and Distribution

Platypus is a native to eastern Australia and is mostly found on streams, rivers, and bodies of freshwater. It is likely to be found in freshwaters where its electrical navigation system is in effect, but it has also been found swimming in salt waters occasionally. Basically, throughout the eastward and westward flowing rivers of the states of eastern Australia, we find these platypus mammals. It is found throughout Tasmania, eastern Queensland, and New South Wales, southwestern, central, and eastern Victoria. Platypuses were once found in Mount Lofty Ranges and the Adelaide Hills of South Australia, but now it is extinct from that state. Platypuses are found in the terrains of the Australian Alps and near the sea, in lowland areas also. 

Features

Platypuses are generally 15 inches (i.e., 38 cm) from their head to their rump. An additional 5 inches (i.e., 13 cm) is added to its length by the tail. Individually, they weigh about 3 lbs (i.e., 1.4 kg). The fossils found by scientists show that the size of ancient platypuses was twice the size of today’s platypuses. Male platypuses are larger than female ones. Platypuses stay warm and insulated underwater, due to their dense, thick fur. They remain dry even after a long period underwater by their long guard hair, which protects the soft underfur. 

The outer surface of the bill is coated with soft, sensitive skin and in the inner, platypuses do not have teeth. They rather have flat, pad-like hard gum tissues. The animal propels through water by its front feet which are webbed extensively. The back feet are used as brakes and rudders while the paddle-like tail stabilizes the body while swimming. 

The skeletal features of a platypus are unique and odd. Such skeletal features include an antique but strong shoulder girdle along with a short and wide humerus which provide strong muscle attachment at the front limbs. On the inner parts of each ankle of male platypuses, a spur is present which is further connected to a venom gland over the thighs. These spurs can be put to use in defense and the venom is highly potent in killing small animals. If the spur penetrates human skin, it causes intense pain. 

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Habitat and Diet

Though they spend most of their time in the water, they totter onto the banks of the river to dig burrows using their claws. These burrows are made like tunnels or chambers where they take shelter. Platypuses also live under debris, roots, and rock ledges. Being nocturnal, they shelter during the day and feed actively from dusk to dawn. They are carnivorous and are dependent on meat. They generally survive on the invertebrates that dwell at the bottom and occasionally feed on insects, fish, or frogs. They are companionless and keeps on feeding almost continuously. 

A hunt may last up to 10 to 12 hours. They dig through streambed debris to excavate freshwater crustaceans and larval insects. The electromechanical system of platypus helps them extensively in catching their prey. The minute electrical signals are radiated from the muscles of their prey and thus, are detected by them. They scoop their prey in the bills and store them in the cheek pouches. Since they don’t have teeth but grinding plates, they use dirt or gravel to mash their food into digestible elements.

After feeding, the platypus heads back towards its burrow which is made so compact that it can accommodate only that platypus and also, squeezes excess moisture from its fur. However, platypuses can also be active during the day depending on the factors like stream productivity, cloud cover, season, or personal preference. Hibernation is not a part of platypus habitat, yet they are found to have an unusually low body temperature of about 32 °C compared to other mammals. According to studies, platypuses are found to maintain a constant body temperature even after prolonged exposure to water with a temperature around 4°C low. This study proves that Monotremes can regulate their body temperature.

Reproduction

Irrespective of the abundance, much about the life cycle of platypus is not known yet. From late winter to spring, mating and courtship take place in water. Depending on the latitude, timing may vary as in northern parts, mating starts early while in southern parts, mating starts a bit late. These mammals avoid each other and only meet during mating. They mate at least after four years of age. 

During the breeding season, the male sex tends to fight and cause wounds on each other by their sharp spurs. From records, it was seen that in one session, the male grasped the tail of the female tightly with his bill as she made him chase her exhaustively. Undoubtedly, mating in platypus is a demanding affair. The males take no part in nurturing the newborn. The females build nursery burrows where two, leathery eggs are laid. The gestation period lasts for at least two weeks to one month at most.

Incubation of platypus eggs takes another 6 to 10 days. Incubation is carried out by the female where she curls the eggs with her tail and bill. Having reptilian structures like egg tooth and fleshy nub (basically a caruncle) helps the platypus to hatch from the egg. The hatchlings suck milk from special mammary hair. They suckle for three to four months in their burrow and remain protected. The weight of the newborn increases by a factor of twenty in the initial fourteen weeks of their life. 

During this period, they possess vestigial teeth which shed shortly. By then, the young platypus leaves its burrow and starts feeding on its own. Both the females and the males grow fully between twelve and eighteen months of age. By their eighteenth month, they become sexually mature. Studies show that platypuses can live for around twenty years in the wild and around twenty-three years in captivity. For small mammals, they are long-lived.

Evolution

From the fossil records, the first occurrence of a platypus like Monotreme is about ten million years ago, during the Cretaceous Period, when Australia was connected to South America, via Antarctica. This Cretaceous monotreme could be partly placed within the platypus family by both molecular studies and dental structures. But recently, these Monotremes are classified as a separate family, Steropodontidae. The living family of platypus is a part of the extinct generation Monotrematum, Obdurodon, and the living Ornithorhynchus. Species of Monotrematum and Obdurodon were found to be more vigorous and retained functional teeth, compared to present platypus and Obdurodon measuring about 24 inches. 

Conclusion

The legislature of all the states where platypus is found protects them from being killed or captured. They can only be captured for scientific research. Platypus is a common species and the abundance is unknown which makes it difficult to predict trends in their population. Due to their habit of spending most of their time in burrows or waters, determining their predators is a bit difficult. But narrative reports state that platypuses are predated on by carpet pythons, eagles, goannas, large native fishes, and crocodiles. Also, the platypuses that move on land or in shallow waters, are heard to be predated on by dogs or foxes. Ixodes ornithothynchi is the tick species of platypuses. These ticks are found in the limbs and body fur of the platypus. This causes a fungal infection which leads to severe skin ulcers. If the fungus invades other tissues of the species, like that of lungs, it can be fatal.

Do You Know These Platypus Facts?

1. While swimming, platypuses cover their nose, ears, and eyes.

2. While on land, the webbed feet of platypus retract and reveal claws that help them in walking.

3. People initially thought platypus to be a fake animal.

4. When underwater, platypuses use their bills to see.

5. Scientists thought the first species of the platypus to be a hoax.

6. Female platypuses do not have nipples. 

7. Platypuses get their sixth sense from their bills.