Fantastic Phalluses and Where to Find Them

Fantastic Phalluses and Where to Find Them

Mother nature has a way of creating a mind-boggling amount of diversity, and animal genitalia is no exception. So, yes, this blog is going to be all about the male appendage: THE PENIS. Big ones, small ones, spikey ones, the four-headed ones – nothing is off-limits.

The idea behind this article actually stems from the second year of my PhD during our weekly (very boring) meetings where we took turns presenting our own or a new piece of relevant research. Instead of talking about the spatiotemporal expression of Interleukin-11 and Forkhead Box Protein 1 throughout the murine endometrium, I decided to talk about penis diversity (naturally).

Hopefully, by talking about penises in a somewhat scientific way, you can come away having learned something about evolution and biology. So, grab the popcorn, sit back, and try to contain the giggles because there will be pictures and there will be puns.

Let’s get the big ones out of the way. The obvious contenders for the largest penises in the natural world are the whales, and coming in at first place is a tie between blue whales and humpback whales at a shuddering 3 METRES long making it as long as a Christmas tree is tall…

Let’s now bring in some of the largest land mammals: Gorillas. Weighing in around 180-250kg, gorillas got pretty shafted in the penis world sporting a 1-2inch penis – maybe good things come in small packages?

The next animals on the list of mighty members are barnacles. Yup. Barnacles. Barnacles spend their entire life sucked onto a rock, a boat, or even a whale, making it pretty hard to find a mate. Unless of course you have the longest penis to body size ratio of any species on the planet. In which case, it’s not so bad. With a penis about 8 times the length of their body, that would make a blue whale’s penis around 220m long or about the size of a 60-70 story building. Clearly, that would be a pretty impractical prick, but for a barnacle, it’s the perfect sexual adaption to its environment. This is called environmental or phenotypical plasticity where animals evolve to live and function better in their environment. Go, barnacle boy!

However, this isn’t the only way animals can evolve. Another cool evolutionary tidbit is something called convergent evolution – where two distantly related animals independently evolve similar traits to adapt to a similar necessity, e.g sex.

Convergent evolution – Baculums
Lucky for you, I’ve got two pretty crude penis examples of this (you’re welcome).

The series of white structures are called baculums, or colloquially known as penis bones (where the term boner came from!). Quite a lot of animals have baculums and they span through almost the entire animal kingdom: Mice, bats, walruses, and even the mighty gorilla with its 1-inch member. So, what’s the point? Why on Earth would mice and gorillas both need a penis bone? No, it’s not an evolutionary cock-up. Animals evolve out of necessity, not by mistake.

It’s actually quite a big area of research and scientists have pumped out a tonne of papers trying to explain why constantly having morning wood is better than turning it on and off again.

There are 3 main theories out there:
– Protect the penis from damage
– To allow for longer mating durations, thus less time for other males to mate with the lucky female
– Overcome issues with blood pressure or ‘not getting it up’

All seem to make quite a bit of sense, and all do solve some sort of issue within each species – it just turns out that evolving to have a penis bone was the solution. That wasn’t so hard now, was it?

Convergent evolution – Penile spines
Yes, those are penises, and, also yes, those are spines on the shaft. OUCH.

If anybody is wincing at the idea of spikey penis sex, you’re not alone. But, like penis bones, penile spines have their own bizarre purpose in the world of animal sex. Felids, wombats, and some snakes have penile spines and there are a few theories, but, to be honest, they’re largely misunderstood little pricks.

However, we do know why and how they work in felids, and why queens (love how that’s the actual term for a female cat) often scream, hiss, and fight their way away from a male during mating. Seminal research in cats proved they are induced ovulators, which means mating is required for queens to ovulate. I.E those penile spines prick the superficial layer of the vagina and send a signal to the brain and ovaries to release an egg – can’t have one without the other. So what about wombats and snakes? Well, it could be that those spines scrape out a rival’s sperm or copulatory plugs (coagulated semen) to increase the chance of ‘reproductive success’ – but we’re still not entirely sure.

So that’s an intro into the confusing, but wonderful world of animal penises. But it’s nothing compared to what I’ve got coming up next… Let’s get into the REALLY WEIRD penises.

Let’s talk about duck cocks.

Ducks are notoriously a bit promiscuous (putting it very politely…), and have developed a pretty incredible spiky, corkscrew-shaped penis (did someone say cockscrew?). There are two possible reasons for this:

1) Potential theory 1: Do duck vaginas also coil? They sure cock-a-doodle-do, so it would only make sense for the penis to match its genital counterpart.

2) Potential theory 2: As I said before, ducks are a bit promiscuous, and having a coiled cock makes sex pretty tricky if the female isn’t willing or receptive – So they’re sort of an anti-rape device in the duck world.

Are four heads better than one?

Looking like something out of the movie Alien, the Short-beaked echidna’s penis is truly something to behold. But then again, almost everything about Monotremes is bizarre… One shaft, four heads, and a four-branched urethra that only semen passes through (urine passes through the urethral branch supplying the cloaca). To make matters weirder, males rotate between pairs of heads they ejaculate from at a time. So, really, their penis acts like two separate penises that just happen to be merged together to form one mega, penultimate penis.

Believe it or not, platypus (the only other living monotreme species) also have a multi-headed penis. So, in Monotremes, the theory argues that the more heads, the more mating or mating success an animal has! In fact, some pairs in captivity have been seen mating >10 times in a very short period, which is going to do wonders for those pesky love handles.

Is.. is that a penis?

Gotcha – This one is actually a trick-penis! Female spotted hyenas sport something called a pseudophallus (or a fake penis) and are an example of sexual mimicry. The pseudophallus is actually an exaggerated clitoris – the internal plumbing remains the same, however. This means they must urinate through their pseudophallus, have sex through their pseudophallus, and even give birth through their pseudophallus. Clearly, there are some mechanical drawbacks, so what good is having a fake rod in the hyena world?

Well, females are the dominant sex, so having higher circulating androgens (testosterone, for example) not only increases physical size and aggression, but may also independently influence the development of a pseudophallus (although this theory is debatable). The second theory is that female hyenas will often kill rival females at birth (this is actually very common in nature). So making it challenging to pick the right prick to kill, could mean you live a bit longer – yaaaay!

The musical member

Let me introduce you to the water boatman. They may be smaller than a drawing pin, but they are the loudest animals on the planet. To make this ridiculously loud sound, water boatman rub their melodic members against their abdomens making a sound about as loud as a helicopter taking off. That’s a pretty powerful penis.

Of course, there is a point to having the rowdiest rod in the world – it’s to attract a mate. I can’t confirm how well the females can hear, but I sure wouldn’t want to be sitting on the lilypad one over from a water boatman screaming from his penis.

Teeny weenies

Scientists can have fun sometimes, and evolutionary biologists really outdid themselves with the naming of this moth: Neopalpa donaldtrumpi. Yes, you read that correctly. There is a moth named after the nauseatingly narcissistic Donald Trump.

This moth has a characteristically Trump-like hairdo, but also a characteristically tiny penis for its species, which reminded biologists of the former president – don’t take my word for it, take it from Stormy Daniels #factchecked.

What a dickhead

This fish looks like it’s straight out of a Stephen King novel, but it’s actually straight out of the depths of the Mekong Delta in Vietnam. Phallostethus cuulong, (which is suspiciously similar to phallus, don’t you think?) was discovered about a decade ago to be armed with a barbed hook attached to its chin used to clutch on to an unsuspecting female. Funnily enough, this sawtooth hook also contains the fish’s penis, so the female comes away pregnant AND wounded – how romantic.

While most fish are external fertilisers (eggs and sperm mix in the sea, rather than inside a body), these fish are internal fertilisers, hence the rod and hook style penis – smart, I guess?

Two sides of the coin

I would be remiss if I didn’t at least mention the female side of things. Penises, although hilariously diverse, are only half the conversation, and there are some astounding differences in female reproductive tracts throughout the animal kingdom, too. However, I’m going to leave that one up to all of you, because my search history is already a bit iffy after googling penis a dozen different ways and reading papers all about how penises work (my recommended ads are very interesting, I can assure you).

If you’re up to the challenge, have a read about the kangaroo’s three vaginas, the two (but only one functional) uterine horns and ovaries of the platypus, or even the elephant vagina, which is about ~1.5METRES away from the vulva.