What are the Oldest Animals on the Planet?

Summary

---

Who Smarted? – "What are the Oldest Animals on the Planet?"

Episode Date: November 26, 2025
Podcast: Who Smarted? – Educational Podcast for Kids
Host: Atomic Entertainment / Starglow Media

---

Overview

In this lively, humor-filled episode, the hosts take a deep dive—literally and figuratively—into the science and surprising facts about the oldest animals on Earth. Guided by a retired marine biologist, Dr. Millicent, and trusty sidekick, Trusty, young listeners are whisked through oceans, underground tunnels, and fascinating biological processes to answer the big questions: Which animal lives longest? How do they do it? And is there really a creature that can live forever?

---

Key Discussion Points & Insights

1. Lifespans in Perspective: Tortoises & More

• Turtle Talk: The episode opens with a fun scene at an old folks’ home, introducing Gretchen the 32-year-old turtle, and noting that some tortoises live over a century.
• Myth Busting: Despite their age, tortoises are not the oldest animals. This sets up the journey for even older species.

2. The World's Oldest Animal: Ming the Clam (Ocean Quahog)

• [05:06] Discovery:
  • "More specifically, it was a type of clam, ocean quahog. And it was 507 years old." — Dr. Millicent (B)
• How Was Ming’s Age Determined?
  • "Most clams have annual growth bands on their shell to tell you how old the clam is. Just like the rings on a tree trunk tell you how old a tree." — Dr. Millicent (B) [07:38]
• Longevity Clues:
  • Ocean quahogs in colder waters have slower metabolisms and grow only during the summer, allowing them to age slowly.
  • Colder water correlates with longer lifespan in several marine species.

3. Relative Longevity: The Naked Mole Rat

• [08:15] Fun Facts:
  • "The naked mole rat can live to be about 30 years old. Which compared to Ming the clam's 507 years, seems like nothing. But if you stop to consider that other rodents only live about five years, then those 30 years are suddenly quite long." — Dr. Millicent (B)
• Why So Long?
  • Living underground, safe from predators, and having slow metabolism.
  • Social animals (colonies with a queen, like ants/bees) also tend to live longer.

4. Longest-Living Mammal: The Bowhead Whale

• [13:48] Reveal:
  • "That's because it's a bowhead whale." — Dr. Millicent (B)
• Superlative Lifespans:
  • Bowhead whales can live over 200 years; some carry 1800s harpoons in their blubber.
• What’s Their Secret?
  • Cold arctic waters slow metabolism, similar to ocean quahogs.

5. Other Longevity Records: The Greenland Shark

• [14:34] Ocean Wonders:
  • "Greenland sharks can also live hundreds of years thanks to cold water slowing their metabolism or growth." — Dr. Millicent (B)

6. Unexpected Contenders: Sponges

• [16:27] Oldest Lifeforms:
  • "Sea sponges might look like plants, but they're in fact, animals. And there's a species of Antarctic sponge that's estimated to be over. Wait for it. 15,000 years old." — Dr. Millicent (B)
• Amazing Adaptations:
  • Sponges continually regenerate stem cells, allowing perpetual renewal.
  • Cold, deep ocean habitats help slow their aging further.

7. Potential Immortality: The Immortal Jellyfish

• [18:23] Highlight:
  • "The longest living creature is the immortal jellyfish, or the Turritopsis dohrnii, to be exact." — Dr. Millicent (B)
• Life Cycle Trick:
  • If threatened, it reverts to a juvenile polyp stage, starting its life cycle over—known as transdifferentiation.
  • "Instead of dying, it just sucks its tentacles back in, shrinks down, and turns back into a polyp. It then starts its life cycle all over again." — Dr. Millicent (B) [19:44]

---

Notable Quotes & Memorable Moments

• On Clam Longevity:
  • "Ming is more than five times older than me, and I'm ancient." — Dr. Millicent (B) [05:20]
• On Metabolism:
  • "It's believed that cold waters slow down animals' metabolism, allowing them to live much longer." — Dr. Millicent (B) [07:06]
• On Sea Sponges:
  • "Sea sponges are constantly regenerating stem cells, so when parts of them die off or break, new parts just grow back. This allows them to continuously renew themselves. How cool would that be?" — Dr. Millicent (B) [17:32]
• On Immortal Jellyfish:
  • "If the jellyfish gets injured, senses danger, or has trouble finding food, instead of dying, it just... turns back into a polyp. It then starts its life cycle all over again." — Dr. Millicent (B) [19:44]
• Running Joke:
  • Trusty repeatedly stresses he "doesn't do great in cold weather."
  • Dr. Millicent pretends to forget which submarine button to press, adding suspense and humor.

---

Timestamps for Major Segments

| Timestamp | Segment | |-----------|----------------------------------------------------------------| | 00:35 | Introduction – Old folks' home & intro to animal aging | | 03:23 | Submarine adventure – reveal of secret sub | | 04:46 | Oldest animal discovered: Ocean Quahog clam, "Ming" | | 05:46 | How clams are aged (growth rings) | | 07:06 | Cold-water effect on animal lifespan | | 08:15 | Naked mole rat’s surprising longevity | | 09:49 | How mole rats live long – slow metabolism, social structure | | 11:30 | Longest living mammal: Hint that it isn’t a human | | 13:48 | Reveal: Bowhead whale as oldest mammal | | 14:34 | Greenland shark: Oldest vertebrate | | 15:36 | Even older: Antarctic sponge (15,000+ years) | | 17:32 | Regeneration in sponges explained | | 18:23 | The "immortal" jellyfish, Turritopsis dohrnii | | 19:44 | Jellyfish reverts to polyp to live again (transdifferentiation)|

---

Thematic Takeaways

• Longevity is Relative: What counts as "ancient" depends on what other animals you compare it to.
• Environment Shapes Lifespan: Cold environments slow metabolism in many animals, allowing them to outlive their warm-water or land-based counterparts.
• Nature's Surprise: Some of the longest-living animals are ones we don’t even notice, like sponges or jellyfish, and some even push the boundary of what "aging" means.

---

Final Thoughts

The episode wraps up with laughter and a return to exercise class, reaffirming the show’s goal: learning is fun, surprising, and full of wild wonders. With playful trivia, engaging storytelling, and actual scientific depth, this “Who Smarted?” installment will leave kids and their families marveling at Earth's most ageless creatures—and maybe just a bit more interested in chilly oceans or jellyfish magic.

---

Transcript

[A]

Hey, smarty pants and smarty families. So today I was supposed to bring you the sad news that this would be the last day of our Special Happy Birthday. 50% off WhoSmarted plus subscription. But guess what? With Thanksgiving and Black Friday coming up, I just had to extend it another couple of weeks. So now you have until the end of November to sign up for WhoSmarted plus and get an entire year of smarting ad free, including a brand new subscriber only bonus episode every single week for just $19.98. That's right. For just $1.66 a month, you'll be supporting the show and giving the gift of smarting to the smartypants in your life. Just in time for the holidays. You can't even get a decent slice of pizza for $1.66. So what do you say? Go to our website, whosmarted.com and click birthday subscribe today. That's whosmarted.com click birthday subscribe. This is only available on our [e-mail]. you and I and all your friends at WhoSmarted will be glad you did. Thanks and happy holidays. And now it's time for who Smarted. Nice work, Millicent. Swing those arms. Sway those 94 year old hips. Stretch and breathe. And stretch and breathe. Hey, smarty pants. As you can hear, I volunteered to teach a weekly jazzercise class at the old folks home in my neighborhood. That's it, Phyllis. Bend and stret and bend and stretch. You're doing great. Of course, I can't work them too hard. They're all pretty elderly. Even the home's pet turtle, Gretchen, is pretty old. She's 32. That may not sound very old for a human, but it is for a turtle.

[B]

Ooh, that's enough aerobics for me, Trusty. Besides, it's time to feed. Gretchen, grab me some of those apple slices, will ya?

[A]

Sure thing, Millicent. Here you go.

[B]

Look at her go. She's got a good appetite for a mature lady. Just like me.

[A]

Uh, no comment. But I will say, turtles live a pretty long time, don't they, Millicent?

[B]

Yep. Especially compared to some other animals like cats and dogs, I'm sure. You know, some tortoises can live to be over a hundred years old.

[A]

Whoa, whoa. Who's right? They must be the longest living animals on the planet, right?

[B]

Wrong.

[A]

Oh, really?

[B]

Really. In fact, there's quite a few other animals that can live much longer.

[A]

Did you know that, smarty pants? Hmm. I wonder what the longest living animals are. And how long can they live? And how are they able to do so? And what's the oldest animal in the world?

[B]

Great questions. And what a handy coincidence for you that I just so happen to be a retired marine biologist.

[A]

That is a handy coincidence. Maybe I should call you Dr. Millicent.

[B]

Maybe you should. Come on, let's go. We can hop in my secret submarine and learn more about the world's oldest animals.

[A]

Um, sorry, did you say secret submarine?

[B]

Yeah, I keep it hidden deep below the old folks home. Direct access to the ocean and everything. But don't say anything. The staff here thinks I just go down there to do my knitting.

[A]

Oh, boy. Sounds like we're in for an animal themed adventure as we take a big old whiff of science and history. On who smarted?

[B]

Who's smarted?

[C]

Who's smart? Is it you? Is it me? Is it science?

[A]

Or history?

[C]

Listen up. We make smarting lots of fun. On who's smart?

[A]

And. Wow, this submarine is so cool.

[B]

Dr. Millicent, thanks, but I really ought to renew my submarine driver's license, though my current one expired in 1994.

[A]

What?

[B]

Don't worry. I know what I'm doing. I meant to do that.

[A]

Anywho, where are we?

[B]

We're just off the coast of Iceland, where the single oldest animal in the world was discovered in 2006.

[A]

Oh, wow. Hey, smarty pants, what animal do you think it was? Was it A, a whale, B, a shrimp, or C, a clam? If you said C, a clam, you're right.

[B]

More specifically, it was a type of clam, ocean quahog. And it was 507 years old.

[A]

Five hundred and seven. Wow. That makes me feel like a teenager.

[B]

I know. Ming is more than five times older than me, and I'm ancient.

[A]

Wait, who's Ming?

[B]

That's the clam's name. When you're a clam that lives to be 507, you definitely deserve a name.

[A]

Absolutely. But wait, do all clams live such a long time? And if not, how was Ming able to live so long?

[B]

Great questions, trustee. Here's the deal. There have been clams that have lived for over 100 years. And there was one that was discovered in 1868 that lived to be 374. But ocean quahogs do seem to live longer than other types of clams.

[A]

And why is that?

[B]

Scientists say one of the reasons is because they seem to grow much slower than other clams. But there's something else that's very interesting. Their growth only occurs in the summertime and ocean quahogs found further south in warmer climates don't live quite as long.

[A]

Wait, so being in colder waters makes them grow slower, which in turn makes them live longer?

[B]

That's what the evidence points to, yes. And researchers have noticed the same phenomenon with other sea creatures too. For example, sea urchins in California live to be about 50. But sea urchins further north on Canada's Pacific Ocean can live to be over 200 years old. It's believed that cold waters slow down animals metabolism, allowing them to live much longer.

[A]

Huh. So if I wanted to live longer, should I move somewhere super cold?

[B]

No. Unfortunately, the phenomena phenomenon doesn't seem to apply to humans.

[A]

Oh good. I don't do great in cold weather, smarty pants. True or false? The way that Ming the Clam's age was discovered was by counting the rings on his shell. The answer is true.

[B]

That's right. Most clams have annual growth bands on their shell to tell you how old the clam is. Just like the rings on a tree trunk tell you how old a tre.

[A]

That's so helpful. Okay, besides clams, what other long living animals are there? And what is considered long anyway?

[B]

Ah, the last question is the ticket. Right here, trusty. You see, it's all relative. And to demonstrate my point, we need to look no further than the naked mole rat.

[A]

The what?

[B]

The naked mole rat.

[A]

Okay, I heard it right the first time. But what's a naked mole rat? They don't live underwater, do they?

[B]

No, but they do live underground. Luckily, the submarine can also transform into an underground burring device. Let me just remember which button it is. Let's see. There's heating, cooling. Increased propeller speed. Decreased propeller speed. Self destruct. Ah, here we go. Terrain. I'll just push that and.

[A]

Wait. That's definitely terrain and not self destruct, right?

[B]

Only one way to find out. Ready, set, go.

[A]

Alright. That was quick. Where are we?

[B]

Somewhere beneath Kenya. Africa, I suspect. Wait. Look. Naked mole rat, three o'. Clock.

[A]

Oh, wow. So ratty, so moley. So naked.

[B]

Yes, they're funny looking little hairless things, aren't they? But so cute. Ah.

[A]

Ah. Ah.

[B]

Remind me why we're here again, trusty. Oh, my memory isn't what it used to be.

[A]

Oh, you were saying long living is relative and that mole rats are a good example.

[B]

Yes, of course. You see, the mole rat can live to be about 30 years old. Which compared to Ming the clam's 507 years, seems like nothing. But if you stop to consider that other rodents only live about five years. Then those 30 years are suddenly quite long.

[A]

I'll say. So what makes naked mole rats live an average of 25 years longer than other rodents?

[B]

Well, the fact that they live underground has a lot to do with it. Inside the little tunnels they burrow. They don't have any natural predators, so they've evolved to live long, safe lives. Like the clams found in cold waters, naked mole rats also benefit from slow metabolisms. Scientists have also found that many animals that are social or live in colonies tend to have long lives.

[A]

Ah. And do naked mole rats live in colonies?

[B]

They sure do. And just like ants or bees, they live in colonies with one queen.

[A]

Wow, that's so interesting. But do you mind if we get out of here? This underground mole rat tunnel is a little claustrophobic and I don't know if I want to meet the queen. Naked mole rat.

[B]

Who should think? Where to next?

[A]

Well, we've learned that Ming the clam lived a whopping 507 years and that mole rats live way longer than other rodents. But I want to know more about the longest living mammal. I bet it's humans, isn't it? And I bet that also means we get to go above ground.

[B]

Well, I hate to break it to you, but you're wrong on both counts, Trusty. For the longest living mammal. It's back to the ocean for us. Ah, back to the magical majesty of the murky blue depths.

[A]

I'm confused. You're telling me the longest living mammal lives way down here?

[B]

You betcha. And look, there's one now.

[A]

What is that, smarty pants? Can you guess what the longest living mammal is?

[B]

The answer is coming up right after.

[A]

This quick break and a word from our sponsors. Hey, Trusty here. You know what's cool? Having your own smartwatch that lets you call and text your friends and family, play awesome games, and even use kidsafe chat to get answers to the kinds of questions I know you love. Like how do birds fly? Or why is the sky blue? That's what Pinwheel smartwatch does. It's designed just for kids so you can call your parents when you need a ride, text your best friend about weekend plans, play fun games, and use the kids safe chat to learn cool new things without any of the stuff you don't need. Parents, you'll love this part. You control who your kid can contact. No strangers, no spam. You can set screen time schedules for school and homework, check messages remotely and track the location with built in gps. Plus, you decide what apps they can access as Your kid grows. Pinwheel grows with them. Start simple, then unlock more features when they're ready. It's why Pinwheel was named the number one kids phone by Parents magazine. This holiday, get up to 50% off with a quarterly or annual subscription plus free shipping and 30 day returns. Visit pinwheel.com smartest that's P-I N W H E-E-L.com smarted now back to who smarted? Okay, smarty pants. We are about to find out what the longest living mammal is. And surprisingly, it's not a human. And it doesn't live on land. Nope.

[B]

That's because it's a bowhead whale.

[A]

Ah, smarty pants, did you guess that it would be a whale? Nice job if you did. So how long can a bowhead whale live?

[B]

Bowheads can live to be over 200 years old. In fact, some have been found with bits of harpoons lodged in their blubber since the 1800s. Ouch.

[A]

So how is it that they can live so long? What's their secret?

[B]

Just like the ocean quahog clams, the cold arctic waters seem to slow their metabolism and give them long life. The same holds true for the world's longest living vertebrae.

[A]

Smarty pants, any idea what that is? Is it the Iceland squid, the Greenland shark, or the Poland pufferfish? If you said the Greenland shark, you're right.

[B]

Greenland sharks can also live hundreds of years thanks to col cold water slowing their metabolism or growth.

[A]

It's such a weird trade off. You get to live a long time, but you're always chilly.

[B]

Tell me about it. But hey, I don't make the rules.

[A]

Alright, so naked mole rats live long for rats. Bowhead whales live long for mammals. And the oldest animal ever was Ming the clam. So I guess we're done here.

[B]

Oh no, we most certainly are not. Ming may be credited as being the single oldest specimen of its species to be found. But there's another type of animal that smarty pants might not even realize is an animal that can live to be tens of thousands of years old.

[A]

Whoa. For real?

[B]

For real. And then there might even be an animal that can live forever.

[A]

Okay, you're kind of blowing my Millicent. Is she blowing your minds too, Smartypants? Uh huh. You're blowing the smarty pants minds too. Okay, let's start with the one that sounds the least impossible. What animal that might not seem like an animal can live tens of thousands of years? Smarty pants, any guesses here?

[B]

I'll do it as one of your little quizzes. If you don't mind.

[A]

For you go for it.

[B]

Okay, is this long living animal? I'm talking about an A, A sea star, B, sea horse, or C, C. Sponge.

[A]

Hmm, that's a tough one.

[B]

It is. If you said sea sea sponges, you're right. Sea sponges might look like plants, but they're in fact, animals. And there's a species of Antarctic sponge that's estimated to be over. Wait for it. 15,000 years old.

[A]

But. But. But how?

[B]

Well, at the risk of sounding like a broken record, let me guess.

[A]

Cold temperatures?

[B]

That's part of it. Sponges and corals live very deep in the ocean where it's cold. So, like the ocean quahogs, they grow long and. And slow. But they can do something else, too that helps with their longevity.

[A]

True or false, smarty pants? A sea sponge can replace dead or dying or broken parts of themselves. The answer is true.

[B]

That's right. Sea sponges are constantly regenerating stem cells, so when parts of them die off or break, new parts just grow back. This allows them to continuously renew themselves. How cool would that be?

[A]

Super cool. And that totally makes sense why they can live so long. But wait, you said there's a creature that can maybe live forever?

[B]

Innocence.

[A]

Yes, smarty pants. Any guesses what this potentially immortal creature is? In fact, I gave you a hint because a word I just said is in its nickname. I'll give you another hint. You might use a shortened version of its name on a sandwich with peanut butter. Okay, got your answer. Why? The longest living creature is the immortal.

[B]

Jellyfish, or the Tauritopsis dorni, to be exact.

[A]

That's right, smarty pants. The creature that could potentially live forever is a jellyfish. But is the immortal jellyfish actually immortal?

[B]

Well, to answer that, let's first talk about a jellyfish's lifespan. You see, jellies have several phases in their life cycle. They start out as a fertilized egg, which becomes a larva. At this stage, it has to find a rock or other hard surface to attach itself to. Once attached, it can develop further, turning into something called a polyp. That's when it starts developing little tentacles. After that, it can free itself from the hard surface and continue developing as a jellyfish.

[A]

Okay, I'm with you so far, but.

[B]

Here'S where it gets unbelievably crazy. If the jellyfish gets injured, senses danger, or has trouble finding food, it, instead of dying, it just sucks its tentacles back in, shrinks down, and turns back into a polyp. It then starts its life cycle all over again.

[A]

Whoa. Whoa is right. For the third time today, it's an.

[B]

Extremely rare natural phenomenon called trans differentiation. And because of this, the immortal jellyfish wins the longest living animal contest.

[A]

Wow. But, you know, as wild and cool as that is, I don't think I'd want to go back to being a baby myself. What about you, smarty pants?

[B]

Yeah, I'm with you on that, trusty. But you know what I would like to go back to?

[A]

What's that, Dr. Millicent?

[B]

Exercise class.

[A]

Oh, you got it. Let's go, doc. Shake out those tentacles. I mean, arms and stretch and breathe. Breathe and stretch and breathe. A double dose of shout out to Nora and Chris in Haverton, Pennsylvania. Thanks so much for listening, laughing and learning along to Whosmarted. We're so glad to have you both being smarty pants in the car. And we love that you love all the funny voices. Keep on smarting, you two. This episode, World's Oldest Animals was written by Phil Jarmy and voiced by Sheila Morrison Suarez and Jerry Colber. Technical direction and sound design by Josh Hahn. Our associate producer is Max Kamasky. The theme song is by Brian Suarez with lyrics written and performed by Adam Tex Davis. Who Smarted was created and produced by Adam Tex Davis and Jerry Colbert. This has been an Atomic Entertainment production.