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| Earth on Jun 27, 2012

Lifeform of the week: The amazing Japanese flying squid

It swims! It flies!
It mates after it dies!
(well, it tries)

 (NOTE: The kites in the above photo look more like octopi than squid, so don’t rely on them for species identification. It’s just not easy finding a good picture of a squid kite.)

After years of ambivalence and procrastination, I finally gave in a few weeks ago and set up a Twitter account. So far I haven’t done much with it besides assembling a newsfeed for myself that is equal parts PBS nature documentary and British tabloid. Each time I log in, I’m greeted with the latest updates on fossilized fornicating turtle discoveries, koala bear chlamydia rates, human tapeworm infestation, and a recent gem reporting “parboiled squid inseminates woman’s mouth.” I retweeted that news, of course, and promptly moved on to other animal kingdom gossip. But I couldn’t shake the story. What kind of creature was this whose reproductive instincts were so strong as to survive death by parboiling?

The squid in question turns out to be Todarodes pacificus, and according to the literature it isn’t the first member of the species to try to mate with a diner’s oral mucosa. It also boasts an intriguing common name: Japanese flying squid. Can it actually fly? Sort of. Can it impregnate a human? Absolutely not. And, really folks, get your mind out of the gutter.

The basics

The non-kite version. Image Credit: Almandine.

Japanese flying squid (also known by the less flamboyant moniker Japanese common squid) are found in northern portions of the Pacific Ocean near Korea, Japan, coastal China, Russia, and across the Bering Strait toward parts of Alaska and Canada.

Females can grow up to 50cm (males are smaller), and both sexes manifest your typical squidy morphology – a long mantle with two fins at the front, eyes, mouth and eight arms plus two tentacles at the rear, and skin that can change color to match the environment. They’re fast little guys, which is useful since they’re predators, dining on fish and crustaceans. Lifespan is similarly speedy, estimated at only about a year.

The flying

Neither its fins nor its arms are the Japanese flying squid’s primary tools for travel. Instead they race through the water via jet propulsion (mantle first during sustained swimming, with limbs dangling behind them). This is done by taking water into the mantle and then forcefully expelling it through a siphon. Whoosh! Other squid (and octopi) also propel themselves in this soaring manner, Todarodes pacificus just happened to get the cool name.

In addition to zipping around in the water, squid sometimes also use their propulsion system to (briefly) glide through the air. It’s not a common sight, and so it was generally believed that this behavior was used to avoid predators, just like so-called flying fish would do. But some researchers now think that leaping into the air actually allows squid to boost their travel efficiency. Using rapid-succession photos of squid breaching the water’s surface, they estimated the animals’ velocity to be five times faster when moving through air. If done with some regularity, this quasi flight could reduce the amount of energy needed for long journeys.

The Japanese flying squid was not the species caught on film and measured, but if they aren’t already partaking of this aerial transportation, they should really consider, it as they undertake a lengthy 2000km migration during their short lives.

The mating

Squid mating is a strangely sequential affair, more of a nice-doing-business-with-you transaction than a cuddly coupling. Males mature first and pass off their sperm to sexually immature females, who store the genetic material and eventually use it to fertilize their eggs. The sperm are housed in spermatophores, structures containing a sperm mass, a spring-like ejaculatory apparatus and a “cement body” (some glue to help the sperm mass adhere to the female).

When Japanese flying squid hook up, the male clutches the female and uses his “hectocotylus” (the fourth right arm, designed for this sort of hand off) to grab some spermatophores and stick them onto the lucky lady. It’s the ejaculation device contained in the spermatophores – not the live male squid – that ultimately sends the sperm mass burrowing through the female’s skin. It’s not a powerful enough mechanism to penetrate the thick skin of, say, a human hand. The delicate mucosa inside the human mouth, however, is no problem.

The unfortunate incident

Warning: may contain sperm. Image Credit: Chrissy Olson.

The Japanese flying squid isn’t unique in either its locomotion or its sperm delivery system. What sets it apart from other squid is its popularity as food, especially in Japan, Korea and other East Asian nations. Often it is sold in a processed, dried form (i.e., no insemination risk), but it is increasingly also consumed raw and sometimes with its internal organs still intact, and thus the species occasionally finds its way into food horror headlines.

According to a case report published in the Journal of Parasitology, here’s how this latest episode of cephalopod sexual assault went down. A 63-year-old woman in Seoul, Korea is preparing a meal. She drops a whole live squid into boiling water for a few seconds (for any inexperienced cooks, “parboiling” is simply partial boiling) then removes it and chops it into pieces. She pops a piece into her mouth to see how it tastes and immediately experiences sharp pains her tongue, gums, etc. Naturally, she spits out the offending food item but continues to feel what she perceives as “bugs” squirming under the skin of her mouth. She packs up the spat out piece of squid and heads for the hospital, where doctors remove twelve “small, spindle-shaped white organisms” from her oral mucosa that are later determined to be squid spermatophores.

Probably safe by now. Image Credit: kvanhorn.

This is the first reported instance of accidental culinary insemination involving a partially cooked squid. In all other cases, unsuspecting diners bit into fully raw squid. But even the raw squid incidents were few and far between. Most squid – raw or cooked – is served sans internal organs and is thus unlikely to contain spermatophores. And calamari’s biggest threat to health is probably the whole breading and frying thing.

In certain media versions of this story, the term “inseminate” morphed into “impregnate”, which is something quite different. I’m tempted to cut writers some slack, as it’s easy to get swept up in the fun of squid sex jokes (see much of above article) but since I don’t want to contribute to any societal confusion about where babies come from, I’m going to have to draw the line here. You can’t get pregnant from eating raw squid. You can, however, contract parasites* or – though it’s less common – a painful bout of spermatophore mouth. Like they keep warning us on the sushi menu, eating raw or undercooked seafood carries certain risks.

* Helpful hint: parasites in raw squid and fish can be killed by freezing the items prior to consumption.