The first known, in the fossil record at least, showed up on a 5-millimeter-long crablike crustacean sporting a “large and stout copulatory organ.” The appendage impressed scientists enough to name the creature Colymbosathon ecplecticos, which means “amazing swimmer with a large penis.”
Since then, all manner of penises have appeared on animals (and in Zoom calls) — some practical, some ingenious and some downright strange.
For a thorough stroll through this portion of the biological world, there’s “Phallacy: Life Lessons from the Animal Penis” (Avery), out now, by science writer Emily Willingham.
First, how to even define a penis? The author narrows it down to “something that inserts into a partner’s genitalia during copulation and transmits gametes.”
It’s a broad definition, because the variation in the animal world is staggering.
Take millipedes for starters. The arthropods get it on with a specialized pair of legs located on their seventh body segment. Another pair of legs located close to the head loads them with sperm, and off they go.
The Japanese yellow swallowtail butterfly has photoreceptors on its genitalia. In other words, it can see with its penis. The “eyes” seem to help “guide [the male] to the right place for copulation.”
Forget romance. Some creatures blindly stab their mate with their penis “like bad fencers” in an attempt to inject sperm. Sea slugs will nail their chosen one in the foot or even the forehead.
It’s an oddly effective way to make babies, because the female body is a “surprisingly benign environment for sperm.” In fact, research has shown that injecting sperm into the body cavities of pigs, cattle and chickens gets results “just as good as what’s achieved with putting semen into the usual place.”
What about the biggest animal penis? That belongs to the blue whale, with an average length of 8 feet. Though the whale has nothing on the barnacle. “Some barnacles can boast a phallus eight times the length of their owners,” the author writes. If a barnacle were the same size as the blue whale, its penis would clock in at 640 feet.
Don’t mess with the Yangtze giant softshell turtle, which uses its penis as a weapon. Might want to steer clear of crocodilians, as well. The animals have permanently stiff penises that “can just pop out, like an airbag.”
A rodent known as the East African springhare has a penis like a “medieval battle device.” It’s got spines, an internal bone and an inflatable tip which it uses like a battering ram against the female’s cervix. Llamas and alpacas have corkscrew-shaped penises that help them couple with the female.
Perhaps most tragic is the honeybee, who, like a nerdy teenager, is literally willing to die for sex. The honeybee has a tiny penis that can only be seen under a microscope, but it packs a punch. After the male couples with the queen, “the ballistic emergence of his semen forces him back,” basically ripping off his penis and killing him.
But, unlike all of these other animals, Willingham says, human genitals aren’t the most important organs when it comes to copulation.
Rather, she writes, it’s the human mind that “deserves to be re-centered as the most fundamental element of our sexual behaviors.”