How Do Platypuses Work?

This creature's amazing amalgam of traits includes fur like a mammal, webbed feet like a bird, eggs like a reptile, electroreception like a shark, and venom that may teach us how to build better painkillers. Learn more about the platypus in this episode of BrainStuff, based on this article: https://animals.howstuffworks.com/mammals/platypus-poison.htm

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Episode Transcript

Speaker 1 (00:01):
Welcome to Brainstuff, a production of iHeartRadio, Hey brain Stuff
Lauren Vogelbaum here. The duck bill platypus has been called
a lot of things since it arrived on the zoological
scene in seventeen ninety eight, but one adjective that's likely
never been applied to this mammal is normal. After all,

(00:23):
its physiology and anatomy borrow from birds, reptiles and mammals,
and a baffling conglomeration. Biology experts in England laughed off
the first skin and sketch brought over from its native Australia,
believing it to be a hoax, and a poorly constructed
one at that. Because the platypus has fur and the
female nurses it's young, the animal is classified as a mammal,

(00:47):
But a female platypus doesn't nurse with nipples. Instead, she
secretes milk into folds of her abdominal skin for the babies,
called puggles, to suckle on. They have duck bills and
webbed feet like birds, and lay soft, leathery eggs like reptiles. Also,
like birds and reptiles, platypuses only have one orifice for

(01:07):
the excretion of digestive remains and for reproduction the chloeca.
The only other living mammals on the planet with this
setup are echidnased. They're together in their own special taxonomical order,
the monotremes. The platypus even shares a special sensory capability
with sharks. The platypus lives in and around rivers and

(01:31):
feeds off of insects, larvae, shellfish, and worms, which it
locates underwater. Because it closes its eyes and seals off
its nostrils upon submersion, the scientists wondered how it manages
to hunt without the help of sight or smell. It
turns out that tiny pores called electroreceptors dot the platypus's bill.

(01:51):
These pores open up into sensitive nerve endings that can
detect changes in the electrical current in the water. Those
electrical currents could be caused by muscle movements or sometimes
by water rushing over stationary objects. As we've talked about
on the show before. Elector reception is the method that
lots of sharks used to hunt too. But these surprises

(02:13):
in this anatomical funhouse don't stop there. We have to
talk about another reptilian similarity platypus venom. The male platypus
as a spur on either hind foot that excretes venom.
Though females are also born with spurs, they fall off
before adulthood. Aside from two other mammals, a certain species

(02:34):
of shrew and solenodons, harboring venom is a trait usually
reserved for reptiles and amphibians. So why would the male
platypus need venom. This relatively docile animal has few predators,
which include carpet snakes, eels, and foxes, and it doesn't
use its venom for hunting. The only probable explanation that

(02:55):
researchers have come up with is that males use it
offensively during mating competition. To back this up, researchers point
to the fact that the male platypus produces venom mostly
during the spring, which is when platypus couples breed. Apparently,
the venom isn't meant to kill other males, only to
provide for a rousing fight. That said, for a human,

(03:18):
getting hit with a dose of platypus venom is said
to really hurt, even though the platypus only weighs around
five pounds that's about two point two kilos. There have
been recorded deaths due to platypus venom in pets like dogs.
There have been no recorded human fatalities, but the venom
will cause swelling at the wound site, an extreme pain
that can last for weeks and isn't touched by drugs

(03:40):
like morphine. Platypus venom share some molecules also found in
reptile venom, but researcher is determined that the platypus's venom
evolved separately, and weirdly enough, this offensive adaptation could end
up helping humans. Since the platypus is one of only
three mammals that produces venom, researchers want to determine the

(04:03):
specific pain response pathway that it stimulates in humans, because again,
our available painkillers don't affect it. They could then utilize
that information to develop new pain relief medications and possibly antibiotics.
Due to the platypus's many anomalies, more than one hundred
scientists collaborated for the Platypus Genome Project, which they completed

(04:27):
in spring of two thousand and eight. Like the human
Genome Project. This undertaking sought to map the entire platypus
genome to understand how an animal with such a hodgepodge
of traits could have possibly evolved. They determined the platypuses
split from our last common ancestor about one hundred and
sixty six million years ago and share about eighty percent

(04:48):
of the same genetic coating as other mammals. One thing
that's different is that they don't have the X and
Y chromosomes that determine the sexes of offspring like in
many other mammals. Instead, platypus sex chromosomes more closely resemble
those of primitive birds, which could provide insight into the
genetic footprinting that led to our own coding. Now that

(05:11):
scientists know more about how this Australian animal evolved, it's
raised more questions as to why it is the way
it is and how it relates to mammals and birds
and reptiles. In just over two hundred years, the platypus
has ascended from a tax durmy hoax to a venomous
guide into the animal kingdom's many genetic puzzles. Today's episode

(05:37):
is based on the article code a platypus poison Me
on how stuffworks dot com, written by Kristin Conger. Brain
Stuff is production of iHeartRadio in partnership with how stuffworks
dot Com, and it is produced by Tyler Klang. For
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