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Ten Bizarre Facts About Sperm And Semen

by Benjamin Thomas
fact checked by Darci Heikkinen

Without sperm, where would any of us be? The tiny swimmers are a vital part of the reproductive process. The milky fluid that helps them travel around is pretty handy too. But that doesn’t change that sperm are peculiar creatures.

Some people don’t like to think about how absurd sperm and semen can be. As the late, great British comedian Jeremy Hardy once said, “Men find it very difficult to accept the idea that there could possibly be anything wrong with their sperm, other than the fact that it’s very hard to clean off a suede jacket.”

But in fact, sperm is the subject of all kinds of weird behavior and strange discoveries. From zero-gravity experiments to drug delivery robots, cryptocurrency to culinary cookbooks, here are ten offbeat things you might not know about sperm and semen.

Related: 10 Old-School And Obscure Birth Control Methods You Didn’t Know

10 Ani Lui’s Mind-Controlled Sperm

Artists have produced an endless amount of mind-boggling concepts over the years. But there are few ideas stranger than brain-powered sperm. Ani Lui, a researcher and artist at MIT, has used cutting-edge technology to bring this bizarre concept to life.

Lui is known for creating research-based art that combines science, culture, and new technology. One of her latest pieces, Mind-Controlled Spermatozoa, is an installation in which she uses her mind to direct the movement of live sperm.

An EEG headpiece tracks the electrical activity coming out of her brain and then converts it into a digital signal. These pulses affect the electronic charge around a sample of live human sperm. One of the strangest properties of human sperm is that it alters its direction to line up with the surrounding electromagnetic field. This phenomenon is known as galvanotaxis and is true of all mammal sperm.

And Ani Lui’s far-flung artistic adventures don’t just stop at mind-controlled sperm. Another of her works, Botany of Desire, featured plants that were specifically engineered to react to chemicals in her lipstick. The result was a piece in which Lui caused plants to bloom just by kissing them.[1]

9 Sperm Can Withstand Zero Gravity

One day, many years in the future, female astronauts may be able to populate new planets with the help of an astronomical sperm bank. So says a new study into the behavior of sperm in zero gravity.

In 2019, researchers discovered that samples of frozen sperm were able to withstand microgravity, the conditions in spacecraft that make it look as if astronauts are weightless. In the study, the exposed samples retained similar properties to those in regular gravity conditions. The team analyzed sperm from ten healthy donors, which they exposed to microgravity using an aerobatic aircraft. The scientists found no significant differences between the zero-g samples and those that remained earthbound.

This is not the first time that the idea of all-female space missions has made headlines. In 2017, British astronaut Helen Sharman claimed that an unreleased document from NASA advised that all crews for long-haul missions should all be of the same gender. Rumor has it the space agency felt that issues around sexual desire would harm the team’s ability to cooperate.[2]

8 Record-Breaking Ancient Sperm

“Scientists find the world’s oldest sperm fossil” (100-million-years old).

In 2020, researchers made headlines after discovering 100-million-year-old sperm, the oldest known sperm in the world. Scientists from the Chinese Academy of Science found prehistoric sex cells preserved in a disc of amber in northern Myanmar.

The sperm in question originates from an ancient, never-before-seen species of ostracod. The ostracod is a strange crustacean creature that looks almost like a shrimp inside the bivalve shell of a clam, earning it the nickname “seed shrimp.” Although most ostracods are around 2.54 millimeters (0.1 inches) long, their sperm can grow as long as 11.8 millimeters (0.46 inches).

The scientists found 39 ostracods in their small sample of amber, the majority of which belonged to a species previously unknown to science. The tiny seed shrimps each measured around 0.59 millimeters (0.02 inches). Inside one of the females, researcher He Wang discovered four eggs and a strange, spooled up mass of protein—an ostracod sperm cell dating back to the Cretaceous period.

Wang’s unprecedented discovery has now been crowned the oldest confirmed sperm in the world. This outstrips the previous record holder, a 50-million-year-old worm sperm found in a cocoon in Antarctica.[3]

7 Big Sperm and the Semen Crisis

The Global Spermageddon | Explorer

I’m sure by now we are all aware of the idea of big tech and big pharma. But how about big sperm? As ridiculous as it sounds, there is a clutch of budding startup companies who believe they have the solution to the growing crisis of falling sperm counts.

Yes, there is genuine scientific evidence that suggests we are in the grip of a semen crisis. According to a 2017 study, the sperm count in men from North America, Europe, Australia, and New Zealand has dropped 59.3% since 1973. And scientists are unable to explain the drastic reduction. Further statistics from the British NHS suggest that when couples struggle to conceive, the issue lies with the man around 40% of the time.

That’s where companies like ExSeed, Yo, Trak, and Legacy come in. These wannabe titans of the market are all offering high-tech methods to overcome this trend of depleting virility. Trak, for example, offers services for sperm testing, sperm freezing, and perhaps strangest of all, sperm training. “In the past, men have mostly shrugged off fertility as a women’s issue,” explains chief science officer Greg Sommer. “Today, men and women recognize the role that men play.”[4]

6 The Driving Factor behind Supersized Animal Sperm

The Big Sperm Paradox

Across the animal kingdom, sperm comes in a variety of sizes. Take the male parasitoid wasp, for example. Its sex cells are less than one-thousandth of a centimeter long. Fruit fly sperm, on the other hand, has a 6-centimeter (2.3-inch) tail—so long it has to coil up just to fit inside the fly.

But why is this? Why is it that certain animals produce sperm over 20 times the length of their own bodies? Hoping to discover the answer, researchers from Stockholm University decided to investigate. They looked into the sex cells of 3,200 species and noticed that size seemed to be determined by the length of the female reproductive tract.

A small reproductive tract in the female of the species tends to lead to larger sperm. A shallow tract means there is less need for the male sex cells to spread out to reach the egg. Small sperm is particularly common among external fertilizers—creatures like fish and sea urchins. They reproduce by ejecting their sex cells into water, so the males produce vast amounts of sperm to increase the likelihood of some getting to the eggs.[5]

5 Fotie Photenhauer, the Semen Chef

Fotie makes Chocolate Peanut Butter Semen Dessert

Semen is much more nutritious than you might imagine. For those who fancy using the gamete-filled fluid to whip up a tasty treat, chef Fotie Photenhauer has the perfect cookery book. His guide Natural Harvest: A Collection of Semen-Based Recipes first came out in 2008, providing readers with a choice selection of experimental meals.

The Amazon description explains what you can expect inside:

“Semen is not only nutritious, but it also has a wonderful texture and amazing cooking properties. Like fine wine and cheeses, the taste of semen is complex and dynamic. Semen is inexpensive to produce and is commonly available in many, if not most, homes and restaurants. Despite all of these positive qualities, semen remains neglected as a food. This book hopes to change that.

“Once you overcome any initial hesitation, you will be surprised to learn how wonderful semen is in the kitchen. Semen is an exciting ingredient that can give every dish you make an interesting twist. If you are a passionate cook and are not afraid to experiment with new ingredients—you will love this cookbook!”[6]

So if you’re up for a sperm-filled kitchen experiment, you can pick up Photenhauer’s book for $30 online.

4 Sperm-Inspired Drug Delivery Robots

Rocket ship-like ‘micro-robots’ inspired by sperm can deliver drugs inside the human body

In 2018, researchers in Britain laid out their vision for a robotic drug delivery system inspired by male sex cells. Writing in the journal Physics of Fluids, scientists at the University of Exeter proposed the idea of miniature swimming drones with a magnetic head and elastic tail, similar to the tadpole-like structure of sperm. These tiny bots, they explain, could be deployed inside the human body, guided through blood vessels using electromagnetic currents.

This isn’t the first time scientists have floated the idea of sperm-like robots, but the Exeter group claims their design is the cheapest and most efficient to date. The researchers were even able to mock up several prototypes, demonstrating in theory how their novel drug delivery system would work.[7]

3 Fertility Doctor Fathers 49 Children

Dutch fertility doctor secretly used his sperm to father 49 children

In 2019, DNA evidence came to light showing that a Dutch fertility doctor had falsely fathered 49 children using his own sperm. Medical expert Jan Karbaat abused his power by impregnating numerous women. The deception mostly took place during the 1980s. At the time, Karbaat worked at a clinic in Bijdorp, near Rotterdam, although it closed in 2009 amid a whirlwind of allegations.

According to the legal firm Rex Advocate, there were “serious suspicions that Mr. Karbaat used his own sperm in the clinic.” He was taken to court in 2017 after some of the donor children began to doubt their true parentage. The doctor died that same year at the age of 89, but authorities managed to seize objects from his home to provide DNA evidence.

DNA tests were conducted in 2017, but the results had to be kept hidden due to other legal proceedings. Karbaat’s donor children had to wait two years to receive full confirmation from the courts. Joey, one of the 49, spoke of his relief to “finally close the chapter” surrounding his parentage. “After a search of 11 years, I can continue my life. I am glad that I finally have clarity.”[8]

2 British Spies Used Semen as Invisible Ink

That Time MI6 Spymaster Captain MANsfield Cumming Ordered His Spies to Use Semen as Invisible Ink

Invisible ink is a vital tool for any spy. It allows you to smuggle information unseen; the message only becomes readable once a chemical fluid has been applied. In fact, the idea of invisible ink is thought to date back to the ancient Greeks and Romans.

Lemon juice was originally the preferred method of invisible communication by the allied forces in WWI. Although effective, it had several limitations. The lemon “ink” could only be used on paper. It required iodine to read the message. And most damaging of all is that enemy forces cottoned on and started sniffing out citrus-scented messages.

So in 1915, Britain’s secret intelligence service MI6 instructed their operatives to use semen as invisible ink. A British official named Mansfield Smith-Cumming is said to have consulted experts at London University on the matter. There were even reports of a spy in Copenhagen who kept a bottle full of semen for such use. But it gave his letters an eye-watering stench. After this, it is said that Cumming had to remind his men that, “fresh operation was necessary for each letter.”[9]

1 The Online Crypto Clamor over Unvaccinated Sperm

Anti-Vaxxers Trading ‘Unvaxxed Sperm’?!

All manner of outlandish things has happened since the outbreak of Covid-19 back in 2020. Sperm-based cryptocurrency is just another news story in the whirlwind of chaos that is modern life.

In certain circles online, unvaccinated sperm has become a highly coveted commodity. So much so that somebody had the bright idea to create a cryptocurrency around it. This all began because conspiracy theorists believe that vaccines harm fertility. Then in December 2021, a group of tech enthusiasts decided to launch a digital coin called Unvaxxed Sperm. As they explained to Vice magazine, they aim to “ensure the continuity of objective scientific inquiry and the freedom of discourse.”

The idea soon caught on. At a recent anti-vax rally in Melbourne, one protestor was seen waving a sign that read, “Unvaxxed sperm is the next Bitcoin.” The crypto’s anonymous creators are said to be working on other anti-vax projects, like a cryogenically frozen sperm project and an anti-vax dating app.

The founders of this sex cell-themed crypto are dubious about the vaccine. They also seem unsure exactly how much they distrust the vaccine. “We’re not anti-vaccine,” developer Jason explained to a journalist, only to clarify later in that same interview, “To a degree, I’d say we are anti-vaccine.”[10]

fact checked by Darci Heikkinen