Harnessing Spineless Sea Creatures' Superpowers

From starfish and sea slugs to jellyfish and sponges, the ocean's invertebrates are some of the most ancient and diverse critters on Earth. And so are their superpowers, as marine biologist Drew Harvell https://ecologyandevolution.cornell.edu/catherine-drew-harvell calls their unique abilities. In her new book, The Ocean's Menagerie https://www.penguinrandomhouse.com/books/723673/the-oceans-menagerie-by-drew-harvell/, she chronicles the amazing abilities of some of these spineless creatures and showcases how they've inspired our science and medicine. Listen to our past episode on nudibranchs — the potent slugs of the sea — HERE. https://www.npr.org/2021/08/31/1032864371/nudibranchs-do-it-better Want to hear more stories about underwater marvels? Email us and let us know at [email protected] mailto:[email protected]. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ atplus.npr.org/shortwave http://plus.npr.org/shortwave. See pcm.adswizz.com https://pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences. NPR Privacy Policy https://www.npr.org/about-npr/179878450/privacy-policy

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• 0:00Speaker 00

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• 0:15Regina Barber?

  You're listening to Short Wave from NPR. When it comes to the ocean, some species get more attention than others.

• 0:26Speaker 02

  There's a lot of interest and excitement, including for me, of whales.

• 0:29Regina Barber?

  Sharks and dolphins also tend to get a lot of love. But marine biologist Drew Harvell fell in love with a different group in the ocean.

• 0:36Speaker 02

  Really, it's the invertebrates that make the gears turn around in terms of function and how the ocean works.

• 0:42Regina Barber?

  These unsung icons of the sea have no backbones, and there's a lot of them.

• 0:47Speaker 02

  There are over 34 phyla of marine invertebrates, from sponges to corals to octopus to sea stars.

• 0:56Regina Barber?

  And as such a big group, they're pretty versatile.

• 1:00Speaker 02

  Invertebrates live everywhere, from the bottom to the top, from shallow water to deep water, from attached to the bottom and in the plankton. So they're everywhere in the ocean.

• 1:11Regina Barber?

  Drew was so fascinated with spineless creatures that she wrote a whole book about these ancient critters and how their long evolutionary histories have led to some interesting biology.

• 1:21Speaker 02

  I think of them as kind of biological impossibilities, sort of like, you know, Superman flying or having invulnerable skin, right? For an animal to photosynthesize, that's legitimately a superpower.

• 1:34Regina Barber?

  And it's not the only one. Across these marine invertebrates, there's a whole bunch of superpowers, everything from regeneration to super strength and even stealing other animals' abilities. Drew says understanding these animals' superpowers not only helps researchers understand the rules of life, the lessons scientists learn from them can transform our medicines.

• 1:54Speaker 02

  Every one of the ones that I talk about in my book also has an important application for humans.

• 2:01Regina Barber?

  So today on the show, the strange world of the ocean's spineless creatures, what their ancient superpowers are and how they continue to inspire human innovation today. I'm Regina Barber. You're listening to Short Wave, the science podcast from NPR.

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• 3:45Regina Barber?

  Okay, Drew, we're talking about the superpowers of marine invertebrates from your book, The Ocean's Menagerie. We're going to talk about a few, starting with sponges, which I have trouble imagining. What should I imagine?

• 3:57Speaker 02

  They're amazingly beautiful. They come in all colors and sizes and shapes, from vases to runners to huge barrel sponges. And they're brown and yellow and green and red and purple.

• 4:10Regina Barber?

  That's amazing.

• 4:12Speaker 02

  And so, I mean, I just get lost when I'm diving, just watching them, because they're so beautiful. And, you know, functionally, they seem to be very, very simple. But then, when you look deeper, they have amazing functions. And sponges have been of great interest to natural products chemists, because it was found that the highest hit rate for anti-cancer drugs was from tropical sponges.

• 4:39Regina Barber?

  Oh, wow.

• 4:40Speaker 02

  We thought the sponges themselves made the chemicals. But we've learned that often it's the bacteria, particular species of bacteria that are housed within the sponge, that actually do the chemical synthesis of these compounds.

• 4:56Regina Barber?

  Can you give me an example?

• 4:57Speaker 02

  I love this one, because a sponge that's bright green, it's in the inner title, everywhere, Halichondria panacea, very common. It houses a strain of Streptomyces bacteria that produces a chemical. And that is now being used in clinical trials for a whole range of different cancers: melanoma, pancreatic cancer, and renal cancer.

• 5:26Regina Barber?

  It's being used now?

• 5:27Speaker 02

  It's being used now. They don't actually pull it out of sponges now. They've actually learned how to create a synthetic derivative. I could go on and on. And I kind of do, in the book, I talk about quite a few examples of cancer drugs that have actually been discovered and produced from sponges.

• 5:47Regina Barber?

  Let's talk about sea slugs next. Introduce us to these critters. Like, what should we know about sea slugs?

• 5:53Speaker 02

  Oh, my God, sea slugs are just, they're the most enchanting of the invertebrates in many ways, just because they're a ridiculous circus of colors and shapes. You know, black backgrounds with lime green stripes and polka dots.

• 6:10Regina Barber?

  Wow.

• 6:10Speaker 02

  Or yellow or pink. They have these beautiful projections that look like flowers all over their backs. I mean, I think everybody who's seen a neuterbrank falls in love with it, just because they're so beautiful.

• 6:26Regina Barber?

  A neuterbrank being like another name for sea slugs.

• 6:29Speaker 02

  Right.

• 6:30Regina Barber?

  Yeah, and I've learned sea slugs are a relative of snails, but instead of having a shell, they have these like chemical defenses in which they they can eat other animals and steal their powers. Can you tell me more about like one of those?

• 6:43Speaker 02

  We have a neuterbrank that lives in the Pacific Northwest that eats sea anemones. And when it eats a sea anemone, it uptakes the stinging cells that sea anemones use in their own defense. They select the immature stinging cells so they don't explode when they're eating them. They pass them all the way through their digestive system and into these little packages on their back. The stinging cell completes its development and is then used as a harpoon by the neuterbrank.

• 7:16Regina Barber?

  Wow.

• 7:17Speaker 02

  And the diversity of this particular group of neuterbranks that does this is very high. They've been very successful particularly in our shallow waters in temperate and tropical ecosystems. So the beauty of the bright colors is a warning to to fish and other predators that, don't eat me, I'm dangerous, I've got explosives and I'll use them.

• 7:41Regina Barber?

  It's almost as if I like if I were to like eat a venomous snake, then somehow I could have venom or something like that. So like, what lessons can can humans learn from that?

• 7:50Speaker 02

  Yeah, I think I think the the lessons we can learn from the ability of neuterbranks to uptake these foreign organs from other groups is in transplantation surgery. It's very hard for us to transplant kidneys, for example, even among different humans, let alone what we try to do from pigs to humans. And the way we do that now is we try to suppress our immune systems. That's not what neuterbranchs are doing. They're playing around with the recognition process. And so it strikes me that there's a real opportunity there to really think a little bit outside the box about other ways to go in and optimize our transplantation surgery.

• 8:35Regina Barber?

  All right, last but not least, my favorite, maybe yours, are sea stars?

• 8:41Speaker 02

  You know, Gina, I think we share that.

• 8:44Regina Barber?

  Okay.

• 8:45Speaker 02

  They're certainly one of my favorites because, I mean, first, they're like Martians. They have

• 8:51Regina Barber?

  Yeah.

• 8:51Speaker 02

  They have multiple arms, they have thousands of tube feet for running around. They have eyes on each end of each one of their arms.

• 9:01Regina Barber?

  Yeah, all their arms are heads. I remember doing a story about that.

• 9:04Speaker 02

  Right, yes.

• 9:06Regina Barber?

  Yeah.

• 9:06Speaker 02

  And so, you know, just as a, as an animal, they're very, very strange. And yet, the thing that just, as a marine ecologist, blows my mind is they're incredibly important ecologically. We think of sea stars as ecosystem engineers because of their power. They're predators, so they eat prey, and they eat a lot of their prey, whether it's mussels, or clams, or sea urchins. Recently, we've been studying one that lives in deeper waters that used to eat all the urchins and control them, but it was decimated by a huge outbreak of disease. I kind of call it the COVID of sea stars because it affected

• 9:50Regina Barber?

  It's the wasting disease, right?

• 9:52Speaker 02

  It's the sea star wasting disease, and it affected over 20 species in addition to the sunflower star, which is the biggest and fastest in the world. I mean, this thing is three feet across. It's huge, and it eats a lot of urchins. When you remove all those sunflower stars, the urchins explode, and they've decimated our kelp meadows. And so Along the entire West Coast, from San Diego up to Washington, we've had declining kelp beds, partly due to the removal of just this one species of sea star.

• 10:28Regina Barber?

  Wow.

• 10:28Speaker 02

  And weirdly, for such a big, powerful critter, it was the most susceptible to this disease. And so it's now on the endangered species list. And we have a, we've been working for a decade on a recovery program for it.

• 10:42Regina Barber?

  I really like this. You're talking about how these sea stars, they're eating these urchins. They also eat a lot of clams. So how, how are sea stars doing this?

• 10:53Speaker 02

  The trick, the superpower, is that it takes them a long time and they can hang on without spending much energy. And they hang on because they have hundreds of tube feet, which are like little suction cups that grip incredibly strong. And then the other part of the superpower is their smart skin. They can basically cross-link the microtubules in their skin to make it stiff, under nervous control, and then hold that without it costing them anything. And so that's how they win, by hour after hour, just hanging on and pulling till the clam is opened.

• 11:36Regina Barber?

  So what, what could humans do with this superpower of like neural control?

• 11:41Speaker 02

  Well, there's been a lot of interesting research trying to use the ideas and the smart skin of sea stars and sea cucumbers in tendon replacement therapies because of the ability to change under neural control. So all of these organisms, and they tend to be invertebrates, that have this, these so-called smart tissues, are a lot of interest in transplantation therapy.

• 12:08Regina Barber?

  In the epilogue of your book, you write, "The most precious resource on our planet is not oil or metal. It's the deep secrets that string our web of life together." What would you like to see in the future in how humans care for the ocean, like in honor of the statement?

• 12:25Speaker 02

  You know, I think that the first step is to try to help people understand just the incredible wonder of, of these resources and their extreme value. And then from there, to take the next step of protecting them.

• 12:42Speaker 02

  These spineless invertebrates have been on our planet for over 600 million years. They're phenomenal adaptations to change, to a changing climate. There are secrets and mysteries that they have solved that are going to be of a lot of use to us.

• 12:59Regina Barber?

  Thank you so much for talking with me today, Drew. I had a wonderful time.

• 13:04Speaker 02

  Thank you. This has been a really fun session, Regina. I loved it, too.

• 13:08Regina Barber?

  Drew Harvell's book, The Ocean's Menagerie, is out now, where you can read about other invertebrates like jellyfish, octopi, giant clams, sea fans, and corals. And if you like nudibranchs, check out our past episode all about these fascinating creatures. We'll link it in our show notes. This episode was produced by Burleigh McCoy. It was edited by our showrunner Rebecca Ramirez and fact-checked by Tyler Jones. The audio engineer was Jimmy Keeley. Beth Zonovan is our senior director and Colin Campbell is our senior vice president of podcasting strategy. I'm Regina Barber. Thank you for listening to Short Wave from NPR.

• 13:53Speaker 00

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