How to Sex an Abalone: A Sea Snail's Story


Ryan Bradley

1. Pick up the abalone. This may require prying the abalone from its hold, and using a stainless steel putty knife is recommended.

But let's back up for a minute, because maybe you're wondering, What is an abalone? Or, Isn't it a board game? And maybe, Why should I care about the sex of a board game you crazyperson? To answer: It is both a sea snail and a board game. But you can't sauté the board game in butter or sell it for $50 a pound in Japan. People don't form international smuggling rings or get themselves eaten by great white sharks over the board game. So we'll concern ourselves with the sex of the sea snail, which matters because the females are worth more. That's the simple answer. But the real reason behind sexing an abalone is more nuanced, and explaining how to do it in five easy steps will take up the rest of this article. The story begins at a farm.

The farm is on the California coast, about 20 minutes west of Santa Barbara on Highway 101, near some old ranches and strands of eucalyptus trees in a canyon called Dos Pueblos. It isn't much of a canyon—more of a sump, really—and there are turkey vultures circling above some cattle, and the hills are as green as County Kerry after last year's fires and last week's rain. Here, beneath a railroad viaduct near the shoreline, under five great black tarps spread across four acres, is the abalone farm. It's run by a man named Benjamin Beede. If you met him, you'd care about sexing abalones too.

Beede is an environmental biologist. How he came to farm abalone is indicative of the creature's unfortunate history. You see, abalone are delicious. For plenty of animals, this is problematic. For a slow moving sea-snail with not much in the way of a personality and a shell that makes a really nice soap dish, it's catastrophic.


Ryan Bradley

When Beede began researching "abs," as they're called, in the mid-1970s, he was working with a team of abalone divers and scientists to bring them back to the wild. The disappearance of the species off the California coast, though terrible (particularly for the abalone), coincided with a serious economic boom in the most seafood hungry nation in the world: Japan. This is all to explain that although Beede is a really nice guy, from the outset he and plenty of others have had an interest in the species because there's money in it. It's always been that way.

2. With the top of the abalone's shell in the palm of your hand, turn the abalone upside down. Do not be alarmed.

The first abalone eaters were ancient. Shell piles (middens) from California's Channel Islands reveal evidence of abalone gobbling from more than 10,000 years ago. But abalone were so numerous, and people so scare, that there wasn't much of a dilemma then. After the Spanish set up shop in Point Lobos, in Northern California, in 1769, they started an abalone cannery—and so began the abalone's long descent into obscurity.

By the late 19th century, abalone were being harvested in earnest: in 1879, 2,000 tons of abalone were removed from California waters, roughly 10 times more than the state now produces, farms included. They were taken for their meat, of course, but also cultured for their pearls, and their shells have an iridescent nacre still prized by jewelers and makers of fancy guitars. With the California shallows stripped bare, hard-hat divers ventured deeper, into the kelp forests. Callum Roberts, in his The Unnatural History of the Sea, writes that these divers, in their heavy suits and lead boots, tethered to boat by rope and air hose, "often collected five or six hundred abalones per person per day." In the kelp beds there were "piles five to twelve animals deep."

No longer. By the time diving for abalone for sport came along, in the mid-20th century, abalone hatcheries were irrevocably damaged. Recreational ab divers are too often blamed for the demise of California's abalone. Really, they just delivered the death blow.

3. Stick the thumb of your free hand between the far side of the abalone's shell and its "foot." It's that black wiggly thing.

We are not the only animals that find abalone so tasty. As plankton, they're gobbled up by any number of unimpressive predators—muscles, barnacles, and a many-tentacled worm-like creature called a terribilis that is the Kobayashi of abalone eating, and can take down 10,000 abalone larvae in an afternoon. Beede and his colleagues discovered the terribilis's eating habits the hard way. After figuring out how to spawn abalone in a lab, they let hundreds of thousands of baby abs free in the wild ... and watched them get got by every predator on the food chain. At this point Beede and company reconsidered their tactics and took the fight back to tanks, where we're more in control of things.

4. The upside-down abalone, in an attempt to right itself, will begin crawling toward your wrist. Do not freak out: It's a snail, so the worst it can do is slime you. Besides, you need to pay attention to the underside of the abalone's shell. Focus.

Beede started farming abs in 1978. His operation today is radically different from back then. As he tells it, "We had these big rectangular tanks and the abalone wouldn't grow nearly as well." Now, the abalones are transferred from one tank to another based upon weight, size, and age. But that's not even the half of it. Beede pumps 2,500 gallons of seawater through his farm every minute. The intake is further out and deeper than it used to be, after an El Niño in 1997 when the temperatures rose and killed about 40 percent of his abs. There's also a UV system on the intake that kills 99.9 percent of all the microscopic marine life that comes in. Every few months he dries out his tanks and flushes them with fresh water.


Ryan Bradley

Beede does all this because of the sabellid worm, which was brought over through the abalone-trade from South Africa and decimated California's farms. In Australia, farmers were not so cautious and the worm got into the wild and wreaked havoc. Beede also keeps cats around to hunt the rats that would eat his abs. The black tarps cover his tanks not because abalones require shade, but because a few years back some crows discovered the place, told their friends, and Beede had himself a situation that would've inspired Hitchcock.

This is all to say that the abalone is sensitive. So attuned is it to environmental conditions, and so easily preyed upon, that it has become a bellwether—its very presence proof of a healthy marine environment. Even the bands on the abalone's shell bear evidence of water conditions, and the abundance of the algae and kelp it feeds upon. Abnormal abalone larvae are proof that something is amiss. All of which brings us back to the importance of sexing.

Beede sells some of his female abs to science, and the profit margins are 25 percent higher than if he were to sell them for meat. Scientists—working on aquariums, or coastlines, even in wetlands—are after the eggs, which are used to ensure water quality. So the species we ate to the brink of extinction, and decorated our necklaces and guitars with, is now getting farmed on land to help keep our seawater less toxic. I don't think the abalone had a choice in any of this, but it still seems awfully noble for a lowly sea snail.

As for the sexing:

5. Look on the far end of the upturned shell: creamy white bands are sperm; blueish bands prove it's female. Now put the abalone back in the water, where it belongs.