A baby hermit crab, or megalopa, is no larger than the tip of a finger. It resembles a tiny lobster: narrow tail and stubby almost-claws. In October 2018, two megalopa officially became hermit crabs when they climbed inside shells, left the water behind, and burrowed under the sand. Although many megalopa make this transition annually in the wild, what sets the journey of these particular crabs apart is that it happened in the New York home of Mary Akers — an artist, crab enthusiast, and, now, the first person in the United States to successfully breed land hermit crabs in captivity.
“It’s a pretty tricky thing,” she told me when we spoke by phone last month. “The hardest part for the crab is going from breathing with gills in the water, finding a shell, putting it on their butt, carrying it out of the water, to suddenly breathing air on land — there’s a lot that had to happen there.”
Only four other people in the world, according to Akers, have managed to transition crab megalopa to land. It’s a difficult process, attempting to simulate the ocean in a small saltwater aquarium: in their larval stages, crabs are so delicate that any fluctuations in temperature and salinity, or spikes in dangerous ammonia and nitrate levels, could kill them all. Not to mention all the special equipment it requires — circular tanks called kreisels, multiple water heaters, mineral and calcium supplements, certain species of algae for the megalopa to eat. Akers said one of the hardest things for her to find were tiny enough shells for the baby crabs to use.
Akers’s success has considerable implications not only for hermit crabs, but for the pet industry and even the environment. “There’s so much we don’t know,” Aker said, about hermit-crab behavior and their contributions to ocean environments. She said it’s hard to study individual hermit crabs in the wild “reliably” because they can change shells, colors, and even biological sex. “There’s no way to mark them,” she said. But breeding crabs in captivity could change all that — scientists will be able to study individuals more closely and gain new insight into how they live in and maintain marine ecosystems.
As far as she knows, Akers is the first in the U.S. to succeed in breeding these species of crabs — Caribbean (purple pinchers) and Ecuadorian hermit crabs, the most common types in pet stores. The hermit-crab community is tight-knit, she said, and if anyone else had done this, she thinks that she would have heard about it by now.
I spoke with Dr. Christopher Tudge, an associate professor of reproductive biology studying invertebrates at American University, about Akers’ achievement. He had heard of her and was “very impressed.”
“Scientists spend a lot of time and money trying to rear the larval stages of different crustaceans,” he said, “and as far as I know, no one has really done it [with land hermit crabs] as successfully as she has done.”
Since last year, Akers has gotten more than 200 crabs to land — the first step toward reshaping questionable practices in a dodgy pet industry.
“I think a lot of people don’t realize where these crabs come from,” Tudge said. “They don’t realize they’re being brought in from many different countries, islands in the Caribbean and Central America. I don’t think they realize it’s probably not a very well-regulated industry.”
Because it’s so rare to breed hermit crabs in captivity, each crab currently for sale in pet stores and tourist shops worldwide was captured in the wild. While this harvesting doesn’t appear to affect hermit crab populations — nothing I researched suggested they’re endangered, though the Smithsonian says this has never been evaluated, and they’re listed as vulnerable in Bermuda — the practice isn’t sustainable, especially if the crabs are being removed from their habitats faster than they’re breeding.
The hermit-crab industry is not particularly regulated, so it’s difficult to know how many crabs are captured and sold as pets annually. But it’s certainly not a small number. They’re available from all major pet retailers, like Petsmart and Pet Supplies Plus, and typically sell for $6 to $10. According to a 2000 New York Times article, Shell Shanty Inc., one of the largest wholesale suppliers of hermit crabs to pet stores and tourist shops, sells more than a million crabs a year (I reached out to Shell Shanty for updated sales numbers, but didn’t receive a response). The 2019 to 2020 American Pet Products Association National Pet Owners Survey doesn’t have a category for crab ownership, but reports that nearly 10 million households in the U.S. have either reptiles or small animals. We can reasonably assume that hermit crabs are a significant portion of that number.
The fate of individual pet crabs is grim: these wild creatures, often impulse purchases made by families on beach vacations, typically live six months to two years in captivity. If left in their natural environment, they can live for more than four decades.
When I worked in a pet store in Knoxville, Tennessee, I often spoke to families looking for an “easy” first pet who had settled on a crab. Kids begged to take one of the splindly, playful creatures home and parents were encouraged by the low price, but people were always shocked when I listed everything they’d need — a bigger tank, proper substrate, salt and freshwater pools, humidity and temperature controls, a few crab friends. Often, they went home with only an extra shell and a small container of food; sadly, most “pet” hermit crabs simply aren’t being cared for well enough to survive, let alone reproduce, in captivity.
Akers is determined to change that. While she is not against people owning crabs as pets, she very much wants to revise the way the public perceives crab ownership. Education is her top priority. “One of the things I really want to do is have them be valued as exotic species who live 50 years,” she said.
Hermit-crab reproduction is tricky because after hatching, zoeae — the larval stage of crustaceans — need to spend the first several weeks of their lives in water. “[People] don’t realize they’re actually marine organisms and still have a link to the ocean,” Tudge said. Though the crabs live on land, “females cannot reproduce without access to seawater.”
“The male deposits the sperm on the outside of the female in little capsules, which she carries around with her for a while,” he explained. “And when it’s time for her to fertilize her eggs, she opens them up.” Additionally, he said that what makes learning about hermit-crab reproduction so difficult is that no one has ever been able to properly observe this process, since it all happens inside the shell.
“They know how to be crabs,” she said. “I tell myself all the time, ‘Let them be crabs, Mary. Let them be crabs.’”
And that’s not even the hardest part to manage in captivity, according to Tudge. When megalopa are ready to grab a shell and walk to land, “you lose a lot of them then,” he said, especially in a lab. He speculated that in artificial settings scientists “just don’t have the right facilities, or the right conditions, or the right cues for them.”
But before any of that can even happen, Akers said, the crabs “have to want to mate in captivity. The conditions have to be good enough and they have to be comfortable enough.” Such conditions aren’t met in your average pet store, nor in the environment most pet crabs are afforded.
Akers emphasized how much of the reproductive process “relies on the crab doing the right thing” before humans even get involved: “They have to take care of the eggs correctly in their shell for about a month,” she said. “And then they have to get them to saltwater.” Depositing the eggs anywhere else — the sand, freshwater — is a “non-starter.”
Depending on the species, crabs pass through four to six larval stages in the water before moving to land. At the first stage, they’re so small you can’t even distinguish between species. When Akers sent a picture of the zoeae to her family, her sister wasn’t even sure what she was looking at: “What,” she said, “those bubbles?”
At that size, the zoeae are not very good swimmers, and it’s easy to lose them in a tank. They even get sucked into Akers’ siphon when she cleans the water. When this happens, she told me, she has to “eyedropper them out of the wastewater and put them back in.”
Akers tries to balance human involvement with crustacean instinct. “They know how to be crabs,” she said. “I tell myself all the time, ‘Let them be crabs, Mary. Let them be crabs.’”
Akers, 54, has been interested in marine animals her entire life. She’s an entirely self-taught ocean advocate; she doesn’t have a degree in biology. “I didn’t do that well in the intro courses,” she said. “I got weeded out.” Instead, in college she focused on her “other love,” pottery, and studied fine arts. She writes fiction and edits at a literary magazine. She’s tentatively thinking about writing a memoir, and would like to publish a scientific article on breeding hermit crabs. To Akers, art and science have always been closely related. She calls herself “a citizen scientist.”
“I look for connections,” she said. “I love providing the correct environment, watching an animal up close live its life, learning from it. I like to nurture things and see them thrive, but I don’t need them to love me back.”
She wondered if this instinct to “tend” is what drew her to hermit crabs in the first place. “As a kid I was always catching bugs,” she said. “I wanted to walk in the creek in bare feet and explore.” As she got older, hermit crabs became a symbol of that feeling for her, of “returning to a different time.”
She recalled how her daughters would play with wild crabs on the beach when they were young; she realized then that she loved “everything” about crabs. “Oh my god,” she said, “they swim, they dig underground, they climb trees, they molt and change. I mean, what’s more appealing? Wouldn’t you love to dig underground in your shell for a month and come up a whole new person?”
In 2014, Akers got back into keeping crabs as pets. She researched the proper way to care for them. She said she could “feel the obsession building” even then, though it was years before she became interested in reproduction.
“In 2016, I had a crab with eggs, the first time I’d ever seen them. I read about it and got all excited,” she said, “but [the crab] ditched them somewhere” rather than depositing them in saltwater. It was enough, however, to intrigue her. When her crab released eggs again in 2017, Akers said she was “all in.”
“I didn’t want to be too crazy starting out, right?” she laughed. “So I thought, ‘I’ll just try it. I’ll put [the eggs] in these jars and we’ll see. It’s okay, I’m not doing anything weird.’” In the jars, some zoeae made it to megalopa, then quickly died — but not before Akers became “totally obsessed.”
She had a year to plan. She said she “MacGyvered” her setup by adding plastic jugs, grow lights, and algae. “My husband calls it my evil scientist laboratory,” she added. (For more details on her tanks, see her blog.)
Even with her preparation, the work wasn’t easy. She called the time commitment “really insane,” estimating she spent eight hours a day caring for the zoeae, changing saltwater, feeding, cleaning, repeat. “And pacing back and forth, worrying, fretting,” she laughed.
“Wouldn’t you love to dig underground in your shell for a month and come up a whole new person?”
“Some days I have to be gone,” she added. “Whatever, I got a life. Those days, they get by with less… I’m trying really hard this year to not make my whole existence about them.” Fortunately, she now works from home in New York, where she lives with her husband, and her daughters are grown. Her other creative and financial pursuits — writing, editing, and selling pottery for hermit crabs on Etsy — allow for plenty of time to care for her crabs.
When we spoke in mid-September, it was day six of this year’s spawn. It takes about 40 days for these species to move to land. To help the crabs on this journey, Akers purchased a small basking ramp used for reptiles that starts in the water and leads to “shore”; she siliconed small shells over the holes so that the crabs wouldn’t fall through on their walk. Once the megalopa have taken shells and left the water, she removes them from the ramp and puts them in her “land tank.” They are so small they fit on her fingertip.
This year, Akers hopes to have even more crabs make it to land. “It’s just like anything — we get a little better every time,” she said. Regarding long-term plans, she said she tries “to have lofty goals but not expectations. I would love to take it as far as it’ll go.”
“I definitely want to get other people doing it,” she said. “I don’t want to be the only one.” She mentioned a few women who’ve been inspired by her success to try.
Akers also plans to start a captive breeding program. From her first spawn, she chose the friendliest crabs — ones that don’t hide or pinch — to breed in the future. Though she predicts she could see her second generation within three years, when the first captive-bred crabs will be old enough to breed, it’s a long journey from here to replace the thousands of crabs harvested and exported from beaches across the world.
It’s a start, however. Except for the 20 crabs she kept, Akers adopted out the rest to responsible owners. To get approved, adopters had to have the correct setup, understand how to properly care for a hermit crab, and agree to participate in a long-term study. She sold them for $50 each — significantly higher than a pet store would sell them — because she wanted the crabs to be seen as exotic species and not throway pets.
“I wasn’t unhappy to make the money,” she said, “but I felt a little weird charging that much. Then I just said, ‘You’re doing this for the crabs. So they’re valued.’”
“I would love for [captive-breeding] to become the way people get hermit crabs,” she added. “The wild crabs should be allowed to stay where they’re born.”
It’s easy to see the value hermit crabs have to their natural environments: They’re bottom dwellers, scavengers, consumers of organic material that would otherwise rot and release too much nitrogen and carbon in the water. The vitality of such a role in marine ecosystems already overloaded by too much carbon is apparent.
Obviously, harvesting hermit crabs doesn’t rank among the most damaging factors contributing to the current climate crisis. It’s a drop, you might say, in the ocean. However, that doesn’t mean Akers’ success isn’t an environmental victory worth celebrating.
“I cried,” she said, when I asked how it felt seeing the first crabs on land. “Part of me was trying not to be too attached to them, just in case. Then one evening, I was just like, ‘Oh my god, there they are.’” She poured a champagne toast. “I tried to savor the moment,” she said. “I just tried to bask in it.”
“They start in one stage and then end up in another,” she continued, awe-struck. “They’re so fascinating. Born in the ocean. They’re born in the ocean. And then they come and live on land.”
“That’s a long walk for a tiny little pinhead animal,” she added. “They’re just these miraculous creatures.”
It’s a long walk we’re on, too, but if there’s anything to learn from these crabs, it’s the importance, the implicit miracle, of taking that first step. Change often starts this way — and hope, sometimes, is no bigger than the first land-bound sea creature, fingernail-small inside a shell.