Harnessing Spineless Sea Creatures' Superpowers

Summary

Podcast Summary: Short Wave - “Harnessing Spineless Sea Creatures' Superpowers”

Release Date: April 28, 2025

Introduction

In the April 28, 2025 episode of NPR's Short Wave, hosts Emily Kwong and Regina Barber delve into the fascinating world of marine invertebrates. Despite their lack of backbones, these sea creatures boast an array of extraordinary "superpowers" that not only sustain ocean ecosystems but also inspire human innovation. Marine biologist Drew Harvell, author of The Ocean's Menagerie, joins Regina Barber to explore the diverse abilities of these ancient organisms and their potential applications in medicine and technology.

Marine Invertebrates: The Ocean’s Unsung Heroes

Regina Barber introduces the topic by highlighting the typically overlooked marine invertebrates compared to their more charismatic counterparts like whales, sharks, and dolphins. Marine biologist Drew Harvell emphasizes their importance, stating, “Really, it's the invertebrates that make the gears turn round in terms of function and how the ocean works” (01:03).

With over 34 phyla, marine invertebrates—from sponges to corals, octopuses, and sea stars—are incredibly versatile, inhabiting every niche of the ocean, from shallow reefs to deep-sea trenches (00:50). Their adaptability and evolutionary longevity, spanning over 600 million years, make them vital to understanding both marine ecosystems and the broader rules of life.

Superpowers of Sponges

The episode begins with an exploration of sponges, which Regina Barber admits she initially struggled to visualize. Drew Harvell paints a vivid picture: “They're amazingly beautiful. They come in all colors and sizes and shapes, from vases to runners to huge barrel sponges” (02:37). Beyond their aesthetic appeal, sponges possess remarkable biological functions. Harvell discusses their significance in medical research, particularly in the discovery of anti-cancer compounds.

“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” (02:52). A notable example is the bright green sponge Halochondria panacea, which houses Streptomyces bacteria. These bacteria synthesize compounds now in clinical trials for treating various cancers, including melanoma, pancreatic, and renal cancers (03:38). Harvell explains that advancements have allowed researchers to create synthetic derivatives of these compounds, enhancing their applicability and accessibility.

Sea Slugs: Masters of Adaptation and Defense

Next, the discussion shifts to sea slugs, particularly nudibranchs, renowned for their stunning colors and shapes. Drew Harvell describes them as “the most enchanting of the invertebrates” due to their vivid patterns and projections resembling flowers (04:34). Their beauty is not just for show; it serves as a warning to predators about their defenses.

One remarkable ability of nudibranchs is their capacity to incorporate stinging cells from their prey into their own bodies. Harvell shares, “We have a nudibranch that lives in the Pacific Northwest that eats sea anemones. And when it eats a sea anemone, it uptakes the stinging cells… [they] pass them all the way through their digestive system and into these little packages on their back” (05:24). These stinging cells mature and function as harpoons, deterring potential predators.

This biological feat inspires potential advancements in human medicine. Harvell suggests that the nudibranchs' method of accepting foreign cells without immune rejection could revolutionize transplantation surgery. “They're playing around with the recognition process,” he notes, hinting at new strategies for optimizing organ transplants without the need for extensive immune suppression (06:31).

Sea Stars: Ecosystem Engineers with Resilient Biology

Sea stars, or starfish, are another focus of the episode. Drew Harvell expresses his admiration for their alien-like appearance and ecological importance. “They are like Martians… incredibly important ecologically,” he states (07:22). Sea stars are predators that control populations of mussels, clams, and sea urchins, thereby maintaining the balance of marine ecosystems.

A significant case study discussed is the impact of sea star wasting disease, which devastated over 20 species, including the large and ecologically crucial sunflower star. Harvell explains, “When you remove all those sunflower stars, the urchins explode and they've decimated our kelp meadows” (08:31). This collapse has led to declining kelp beds along the West Coast, highlighting the critical role sea stars play in their environments.

The resilience of sea stars is another marvel. Their "smart skin" allows them to grip surfaces tightly using hundreds of tube feet, which Harvell describes as “little suction cups that grip incredibly strong” (09:33). Additionally, their ability to control their skin's stiffness through neural mechanisms enables them to sustain prolonged exertion, such as opening clams without expending excessive energy.

Human Applications: Learning from Marine Invertebrates

The episode underscores how the superpowers of marine invertebrates can inspire human innovation:

1. Medical Advancements: The chemical compounds derived from sponges, produced by symbiotic bacteria, are paving the way for new cancer treatments. Additionally, the immune tolerance observed in nudibranchs offers potential breakthroughs in transplantation surgery.

2. Biomimicry in Technology: The "smart skin" of sea stars is influencing tendon replacement therapies. Researchers are exploring how the neural control mechanisms in these invertebrates can lead to advancements in flexible, resilient materials for medical use.

Harvell emphasizes the importance of understanding these organisms not just for academic interest but for their practical applications that could transform human health and technology.

Conclusion: Preserving the Ocean’s Secrets

In the epilogue of her book, Harvell asserts, “The most precious resource on our planet is not oil or metal. It’s the deep secrets that string our web of life together” (10:49). The episode concludes with a call to action for greater appreciation and protection of marine invertebrates. Harvell advocates for public education to foster a sense of wonder and recognition of the immense value these creatures hold, not only for ecological balance but also for their untapped potential in advancing human knowledge and capability.

Regina Barber wraps up by highlighting Harvell’s book, The Ocean's Menagerie, which explores other invertebrates like jellyfish, octopi, giant clams, sea fans, and corals, encouraging listeners to deepen their understanding of these remarkable sea creatures.

Notable Quotes:

• Drew Harvell (01:03): “There are over 34 phyla of marine invertebrates, from sponges to corals to octopus to sea stars.”

• Drew Harvell (02:52): “We thought the sponges themselves made the chemicals, but we've learned that often it's the bacteria… that do the chemical synthesis of these compounds.”

• Drew Harvell (05:24): “They pass them all the way through their digestive system and into these little packages on their back.”

• Drew Harvell (06:31): “I think 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.”

• Drew Harvell (07:25): “They are like Martians… incredibly important ecologically.”

• Drew Harvell (09:33): “They have hundreds of tube feet which are like little suction cups that grip incredibly strong.”

• Drew Harvell (10:49): “The most precious resource on our planet is not oil or metal. It’s the deep secrets that string our web of life together.”

Final Thoughts

This episode of Short Wave illuminates the extraordinary capabilities of marine invertebrates and their pivotal roles in ocean ecosystems. Through the insights of Drew Harvell, listeners gain a deeper appreciation for these "spineless" creatures and their potential to inspire breakthroughs in medicine and technology. The discussion serves as a compelling reminder of the importance of marine conservation and the untapped possibilities that lie beneath the ocean's surface.

Transcript

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[Regina Barber]

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

[Drew Harvell]

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

[Regina 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.

[Drew Harvell]

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

[Regina Barber]

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

[Drew Harvell]

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

[Regina Barber]

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

[Drew Harvell]

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.

[Regina 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.

[Drew Harvell]

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.

[Regina 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, but the lessons scientists learn from them can transform our medicines.

[Drew Harvell]

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

[Regina 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 Shortwave, the science podcast from NPR Foreign. Okay, Drew. We're talking about the superpowers of marine invertebrates from your book the Oceans Menagerie. We're going to talk about a few, starting with sponges, which I have trouble imagining. What should I imagine?

[Drew Harvell]

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.

[Regina Barber]

That's amazing.

[Drew Harvell]

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.

[Regina Barber]

Oh, wow.

[Drew Harvell]

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.

[Regina Barber]

Can you give me an example?

[Drew Harvell]

I love this one, because a sponge that's bright green. It's in the inner title. It's everywhere. Halochondria 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.

[Regina Barber]

It's being used now.

[Drew Harvell]

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.

[Regina Barber]

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

[Drew Harvell]

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 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 nudibranch falls in love with it just because they're so beautiful.

[Regina Barber]

A nudibranch being like another name for sea slugs, right? 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?

[Drew Harvell]

We have a nudibranch 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 def. 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 nudibranch.

[Regina Barber]

Wow.

[Drew Harvell]

And the diversity of this particular group of nudibranchs 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 fish and other predators that don't eat me. I'm dangerous. I've got explosives, and I'll use them.

[Regina Barber]

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

[Drew Harvell]

Yeah, I think the lessons we can learn from the ability of nudibranchs 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 nudibranchs 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.

[Regina Barber]

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

[Drew Harvell]

You know, Gina, I think we share that.

[Regina Barber]

Okay.

[Drew Harvell]

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

[Regina Barber]

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

[Drew Harvell]

Right, yes. And so, just as an animal, they're very, very strange. And yet the thing that just as a marine ecologist blows my mind is they are 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.

[Regina Barber]

It's the wasting disease. Right.

[Drew Harvell]

It's the sea star wasting disease. And it affected over 20 species. 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. 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've been working for a decade on a recovery program for it.

[Regina 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?

[Drew Harvell]

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.

[Regina Barber]

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

[Drew Harvell]

Well, there's been a lot of interesting research trying to use the ideas in 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 these so called smart tissues, are a lot of interest in transplantation therapy.

[Regina 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, you.

[Drew Harvell]

Know, I think the, 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. 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.

[Regina Barber]

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

[Drew Harvell]

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

[Regina 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 Burley McCoy. It was edited by our showrunner Rebecca Ramirez and fact checked by Tyler Jones. The audio engineer was Jimmy Keighley, Beth Donovan 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.

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