The internet was shocked and astonished a couple weeks ago, when we all learned that a woman ate some parboiled squid — which managed to inseminate her mouth, because its spermataphores were still functioning. How could this happen? Danna Staaf from Squid a Day, who first brought this cringe-making phenomenon to light, explains the science of squid sperm... and human mouths.
Top image: National Geographic/Brian Skerry.
Have you heard the one about the squid sperm that stung a woman in the mouth?
A quick recap: while eating a parboiled squid, a Korean woman felt pain in her mouth. She went to the hospital, where the doctors extracted twelve squid spermatophores-packages of sperm-from her tongue, cheek, and gums. Ew! Also, ouch!
But this poor woman was not the first victim of "oral stinging by squid spermatophores." No fewer than sixteen such cases have been documented in medical literature. However, this was the first case in which the squid was not consumed raw, but parboiled. Are squid spermatophores really so indestructible as to survive cooking?
Probably not. As squid spermatophore researcher José Eduardo Marian of the University of São Paulo points out, the whole squid spent just a few seconds in boiling water. Spermatophores reside in a sac inside the squid's body cavity, or mantle-which might have been open to the water, or might have been tightly closed by the animal's muscles. '"Certainly the temperature was high," he tells us, "but we do not know if there was enough time for the spermatophores to contact the water."
Of course, squid spermatophores aren't meant to be parboiled and eaten. Their purpose is to inseminate a female squid and make baby squid. But as bizarre as these cases of oral stinging are, Marian has actually been able to use one of them to gain a better understanding of the normal functioning of the world's most complicated sperm delivery vehicle.
In a paper just published in the journal Zoomorphology on an earlier case of oral stinging, Marian explains that spermatophores-of which a male squid can produce hundreds-function "autonomously and extra-corporeally." That means they're totally self-contained machines. They don't need any input from a male squid, and, because they work normally in human mouths, apparently they don't need any input from a female squid either.
The sperm mass is home of millions of little swimmers. The rest of that fancy gadgetry allows each spermatophore to independently ejaculate (true!) and attach itself to a female squid.
Scientists once thought that spermatophores just glued themselves to skin with the cement body. A few exceptional species, such as the giant squid, were found to have "deep implantation" — sperm masses injected far into the skin and muscle. It was easy to assume that in these cases, the spermatophores had been dropped into a wound that had already been creating by biting or scratching — or even forced under the skin by a hydraulic penis (yes, that was a real scientific hypothesis). But in 2007, researchers Henk-Jan Hoving and Vladimir Laptikhovsky proved that spermatophores can actually implant themselves.
And then Marian made an even more sweeping claim. In a 2012 article in the Journal of Morphology, he suggested that "tissue scarification" is intrinsic to the action of all squid spermatophores. In other words, they will all cut you. The only variable is the depth of the wound.
But how do they cut you? Observe this vivid film of Marian's:
Okay, that's freaky as all get out! Let's break it down into a tidy four-step process:
First the spermatophore cap must be pulled off. In the video, it's done with tweezers; in a diner's mouth, it could be done by chewing. During natural mating, the male squid might rupture the cap himself as he passes spermatophores to his beloved. Once the cap is broken, the ejaculatory apparatus pops right out.
In the second step, the apparatus everts itself, pulling the sperm mass along with it. When it contacts a female squid (or human mouth), tiny caltrop-like accessories called stellate particles help it to grab on and dig in. Implantation occurs as the apparatus continues to evert, pulling away old particles and the skin cells to which they're attached.
Third, the cement body gets in on the action with a veritable arsenal of weaponry: a sharp tip, more stellate particles, and a super-sticky adhesive. The spermatophore is well and truly attached.
The fourth and final step completes the transformation of a spermatophore into a spermatangium, a sperm mass attached to a female squid (or human mouth). The empty case floats away and some sperm begin to swim around freely. Others may remain in the spermatangium for days, awaiting the female's pleasure.
Now the real question: Why? Are male squid sadistic punks? Of course not! Spermatophores are evolution's answer to the problem of turbulent ocean sex. When waves and currents buffet you and your sweetheart, how can you keep your sperm from being whisked away, before it can do its job? Not to mention the fact that competing male squid might be enhancing the turbulence, using jets of water to try to flush your sperm out of the picture.
The incredibly fancy spermatophore is simply a necessary tool for male squid to ensure the propagation of their genes. Unfortunately for at least sixteen hopeful suitors, human mouths are an evolutionary dead end.