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What the Heck Are Sea Monkeys, Really?

Brine shrimp swimming in the water
Pix Pack Factory/Shutterstock

They’re a staple of childhood: A colorful, plastic aquarium full of tiny “pets” you can allegedly teach to do “tricks.” They’re called Sea-Monkeys, but have you ever stopped to wonder what Sea-Monkeys are, really? Spoiler alert: They are neither monkeys nor sea creatures.

It’s perhaps unsurprising that Sea-Monkeys aren’t monkeys, because, well, look at them. They are clearly not mammals, and they are clearly not related to any primates we know of on Earth. It might, however, come as something of a surprise that they’re not actually ocean-dwellers—and the story of how they came to be the touchstones that they are is even more bizarre than you probably think.

Here’s everything you ever wanted to know about Sea-Monkeys, and then some.

The Science of Sea-Monkeys

First things first: What are Sea-Monkeys, exactly? It turns out that they’re a breed of aquatic crustacean belonging to the Artemia genus—that is, they’re brine shrimp. But here’s the thing: Brine shrimp don’t live in the ocean. In the wild, they’re found only in saltwater lakes. For example, wild Artemia are particularly prevalent in the Great Salt Lake, where geological evidence shows they’ve lived for around 600,000 years. That’s right: “Sea-Monkeys” have absolutely nothing to do with the sea.

Usually no more than a half-inch long, brine shrimps’ contribution to the ecosystem is primarily as a food source. In the wild, birds like to snack on them; meanwhile, in domestic situations, they’re often used as aquarium food. They’re particularly nutritious for tropical fish and can be both purchased at pet and fish supply stores or grown and hatched independently.

But these little crustaceans have a neat trick up their proverbial sleeve—something that makes them pretty unique in the animal kingdom. When their environment isn’t conducive to survival, their eggs, called cysts, undergo cryptobiosis. When there’s no water around, they can exist in a state of rest for extended periods (think months or even years), only to bounce back into action when conditions improve. It’s this trick that allows Sea-Monkeys to work their magic. The eggs you receive in a Sea-Monkey aquarium kit are in their resting state. Once you’ve prepared their tank with the “Water Purifier” packet included in each kit, thereby creating an ideal environment for the creatures, the saltwater will allow the cysts to re-hydrate and begin hatching when the eggs are introduced to the situation.

Sea-Monkeys are meant to hatch instantly, but in practice, they might take about 24 hours to emerge. After that, they’ll grow to adulthood in four to 10 weeks. They grow to be somewhere between a half-inch and three-quarters of an inch long, with the standard food that fuels that growth including yeast and spirulina. (They only need to be fed once a week, though, so don’t overfeed them; if you do, you’ll end up killing them.) One of their weirder characteristics involves their eyes: When Sea-Monkeys first hatch, they have only one eye; once they reach adulthood, however, two more will emerge.

For the curious, brine shrimp can reproduce both sexually and asexually—so if you play your cards right, your Sea-Monkey starter kit could yield generations of pets to come. Indeed, research has found that male Sea-Monkeys are unusually rare. Good thing female Sea-Monkeys can take care of propagating the species all on their own!

The Weird and Wild History of Sea-Monkeys

Of course, average, everyday brine shrimp wouldn’t have become the coveted pet that they are today without someone deciding to market them as such.

That someone was Harold von Braunhut.

In 1956, Uncle Milton introduced the ant farm to the market, leading the widespread popularity of unusual “pets” that could be kept in an enclosed container on a tabletop and required very little in terms of financial investment to breed and upkeep. And according to von Braunhut, an inventor and marketer who held nearly 200 patents (and also, unfortunately, ties to white supremacist groups) by the time of his death in 2003, it was about a year later that he spotted bring shrimp being sold as aquarium food in a pet store and got to thinking. “I was always interested in wildlife, and I was looking for something that would interest other people in it,” he told the Baltimore Sun in 1997.  The fact that brine shrimp eggs could survive desiccated conditions and revive when added to water with the correct saline levels fascinated him, so that’s the angle he took: When he first brought a form of Artemia to market, it was under the name Instant-Life.

This name, however, failed to garner interest in the product, so von Braunhut returned to the drawing board. Observing that adult Artemia have long, monkey-like tails, he struck upon the name Sea-Monkeys and went to town with it in his advertising efforts.

original Sea Monkeys print ad

With only a minimal budget, von Braunhut’s ads were limited to comic books, rather than television commercials — but that proved to be a lucrative direction to take. Featuring cartoonish illustrations of an anthropomorphized Sea-Monkey family drawn by comics legend Joe Orlando, the mail-order ads were ubiquitous in comic books throughout the 1960s and 1970s, painting a picture of a fanciful world kids could grow themselves for just a few dollars.

Did the hatched brine shrimp ever grow into anything resembling the cartoon characters depicted in the ads? Not even remotely. Were they successful anyway? Absolutely.

The ads capitalized on one of Artemia’s key characteristics: They’re sensitive to light, which means that if you aim a flashlight at them and move it around, they tend to follow it. They also freak out when they’re put in darkness and then exposed to light again. The Sea-Monkey advertisements spun these behaviors as tricks you could train the shrimp to do. This became a central part of the Sea-Monkeys mythos as time went on, leading not only to elaborately-themed deluxe kits (how about a trip to the Sea-Monkey Circus?) but also to media deals including a live-action television show in 1992.

Sea-Monkeys remain popular today; indeed, they’re such a massive part of our cultural landscape that the phrase “sea monkeys” is often used as a colloquialism for brine shrimp in popular science writing. You can still buy the classic kits, of course—but now, there’s even an “Executive Sea-Monkeys” kit marketed as an office pet for adults. Who says being a grownup means you actually have to grow up?

An Artemia by Any Other Name

Perhaps the most interesting thing about the whole Sea-Monkey saga, though, is this: There’s quite a lot of debate over what the precise variety of Artemia marketed as Sea-Monkeys really is.

The toy’s lore states that they’re an artificial breed—a hybrid of several existing Artemia breeds called Artemia NYOS and closely related to the Artemia salina brine shrimp. Artemia NYOS was reportedly invented by marine biologist Anthony d’Agostino in conjunction with Harold von Braunhut. The NYOS is meant to stand for “New York Ocean Science,” a reference to the New York Ocean Science Laboratory in Montauk, New York, where d’Agostino worked. (The Ocean Science Laboratory is now defunct; it lost its funding in 1986, according to d’Agostino’s 2017 obituary in the East Hampton Star.)

However, the Artemia NYOS bring shrimp may not have been the original Sea-Monkey or even the original Instant-Life. According to most accounts, this particular brine shrimp was a later development in Sea-Monkey history. Created in response to the difficulty most early Sea-Monkey owners had to keep their pets aliveArtemia NYOS was meant to offer would-be Sea-Monkey keepers a hardier creature to raise—one which would, ideally, last more than one or two months at a time.

It’s not stated anywhere what species von Braunhut sold before the creation of Artemia NYOS. He historically kept most of the details about his product locked down tightly—but most sources are in agreement that it was likely just Artemia salina itself. (Indeed, the patent von Braunhut held for his “Method and materials used for hatching brine shrimp” even referred to the eggs of the brine shrimp in question as “of Artemia salina type or the like.”)

It’s also worth noting that Artemia NYOS doesn’t appear to be recognized as a species of Artemia by the scientific community. Indeed, as the non-profit organization the Centre for Agriculture and Bioscience International’s datasheet on Artemia observes, “hybridization between different species in nature, due to deliberate or indeliberate introduction by man, has not been documented so far.”

Even so, though, given Sea-Monkeys’ longevity, it’s clear that they’re here to stay. So, hey, the next time you’ve got some extra time on your hands for a new project, why not try raising your own Sea-Monkeys? Just add water, and you’re good to go!

Lucia Peters Lucia Peters
Lucia Peters is a writer and editor based in Washington, D.C. Her work has appeared at Bustle, The Toast, Crushable, The Gloss, and others. She also writes and manages The Ghost In My Machine, where she haunts readers several times weekly with spooky stories of the strange and unusual. Her first book, Dangerous Games To Play In The Dark, was published by Chronicle Books in September of 2019. Read Full Bio »