DUCK-billed, beaver-tailed, web-footed, egg-laying and venomous, the platypus is one of Mother Nature’s weird and wondrous enigmas.
Scientists used to scoff at the notion that the platypus was a real animal at all. In fact, those who had the privilege of examining a preserved platypus in the 1700s assumed it was a ‘chimaera’ made by a prankster sewing random animal parts together.
Nowadays, not only does the general public know that the platypus is very much real, but it has also become a beloved Australian mascot and an animal of extreme interest and importance to biologists due to its unique anatomy.
That being said, while most are aware of the platypuses’ quirky appearance, did you know that they are just as unusual on the inside? For example, it is claimed that these critters do not have a stomach at all.
Is this true?
VERDICT:
TRUE
Defying all conventional wisdom yet again, the platypus is an exception in the mammalian world in that it does not possess a functioning stomach. Instead, its gullet connects directly to its intestines with nothing in between.
While many fish (almost a quarter!) have evolved away from having stomachs, it is still an essential organ for the vast majority of mammals, some of which even have more than one stomach.
This can be explained via evolutionary needs – the stomach is essentially a sack that secretes acids and enzymes to help an organism break down food. Developing such an organ allowed vertebrates to consume and digest more complex molecules, opening the doors to more varied or nutritious diets.
However, if an animal’s diet does not require such heavy-duty digestive enzymes, the stomach becomes a worthless and redundant organ.
In the case of the platypus, whose relatively digestible diet consists of bottom-dwelling invertebrates such as insect larvae and small crustaceans, this could very well be true.
Common sense might tell you the hard shells of their crustacean prey warrant the need for a stomach, but scientists say that animals that primarily feed on shellfish and corals are in even less need of such an organ. This is because the calcium carbonate-rich shells neutralise any acid the stomach might produce.
Interestingly, most species that have abandoned the stomach completely lose the genes associated with such an organ.
In the case of the platypus, a study revealed that key genes associated with gastric functions had completely disappeared from the platypus’ genome, “reflecting a unique pattern...not previously seen in other mammalian genomes.”
This means the platypus would need to rebuild a stomach-like structure from the ground up if its evolutionary needs ever called for such a drastic change.
However, according to a principle known as Dollo’s law, “an organism never returns exactly to a former state, even if it finds itself placed in conditions of existence identical to those in which it has previously lived.”
This means the platypus, its fellow Australian icon, the echidna, and the multitude of fish species that have abandoned the digestive organ are unlikely to ever return to a ‘stomached’ state.
Far from being a disadvantage, this simply highlights the wonders of evolution and the capacity of organisms to adapt to their environmental and dietary needs.
Now, for more pressing matters: is the plural of platypus - platypuses or platypi? And how many of them go by Perry?
Sources:
3. https://www.livescience.com/
4. https://www.iflscience.com/
Pic options:
1. https://commons.wikimedia.org/
3. https://pixabay.com/photos/
4. https://www.freepik.com/free-
