If you’ve visited our touch tank, you’ve probably met one of our most popular residents — the sea star. But wait, isn’t it called a starfish? You’re not alone in wondering. The names “sea star” and “starfish” are used so interchangeably that most people assume they’re two different animals. The truth is much simpler — and a little more interesting.
Same Animal, Better Name
Sea star and starfish refer to the exact same creature—invertebrates in the class Asteroidea—but “sea star” is the preferred scientific term because they are not fish. As echinoderms, they lack gills, scales, and brains, instead using a water vascular system with tube feet to move and hunt.There are no biological differences between them because they are one and the same. “Starfish” is the older, more traditional common name, while “sea star” is the modern preferred term used by marine biologists, aquariums, and educators.
So why the shift? Because starfish aren’t actually fish. They don’t have gills, fins, or scales. They don’t swim through the water column the way fish do. Calling them “starfish” is a bit like calling a jellyfish a fish — technically misleading. The name “sea star” more accurately reflects what these animals are: star-shaped marine invertebrates that belong to the class Asteroidea.
What Makes a Sea Star So Special?
Now that the naming mystery is solved, let’s talk about what makes the sea star in our touch tank such a fascinating creature.
Sea stars have no brain and no blood. Instead of blood, they pump seawater through their bodies using a water vascular system, which also powers the hundreds of tiny tube feet on their underside. Those tube feet are what you might feel gently gripping your hand when you pick one up in the touch tank.
Most sea stars have five arms, but some species can have 10, 20, or even 40. And here’s a crowd favorite: if a sea star loses an arm, it can grow it back. Some species can even regenerate an entirely new body from a single arm.
They also eat in one of the most unusual ways in the animal kingdom. A sea star can push its stomach out through its mouth, wrap it around its prey — like a mussel or clam — and digest the meal externally before pulling its stomach back inside.
Why We Use the Name “Sea Star”
At our facility, we use the term “sea star” because we believe in teaching accurate, up-to-date science. Language shapes how we understand the natural world, and small corrections like this help visitors — especially young learners — build a clearer picture of ocean life. Fish are fish. Sea stars are something else entirely, and that’s what makes them so remarkable.
“People come in all the time calling them starfish, and that’s totally okay — it’s what most of us grew up saying,” says Lead Aquarist Mikey Vittum. “But once you explain that they’re not actually fish, you can see the lightbulb go off, especially with kids. It’s one of those small moments that gets people thinking differently about the ocean.”
Come Meet Our Sea Stars
Our sea star lives in a 200-gallon touch tank at our Environmental Education Center in downtown Blue Hill. The touch tank is just one of many hands-on experiences waiting for you. The center also features marine mammal skeletons and bones, aquariums, an interactive virtual ocean explorer, a gift shop, rotating artwork, lab tours, and more … and admission is FREE!
The Environmental Education Center is open Thursday through Saturday, 10:00 AM to 4:00 PM. Stop by, roll up your sleeves, and say hello to our sea star — not starfish — for yourself.
Frequently Asked Questions
Is a sea star the same thing as a starfish?
Yes! They are the same animal. “Sea star” is simply the more accurate modern name, since these creatures are not actually fish.
Is it safe to touch a sea star?
Absolutely. Our touch tank is designed for gentle, supervised interaction. Just be sure to follow staff instructions — use flat, wet hands and avoid lifting the sea star out of the water.
Can a sea star really regrow its arms?
Yes. Most sea stars can regenerate a lost arm over time, and some species can even regrow an entire body from a single arm.
Are sea stars related to fish at all?
No. Sea stars are invertebrates — they have no spine, no gills, and no scales. They’re actually more closely related to sea urchins and sand dollars.
How does a sea star move without legs or fins?
Sea stars use hundreds of tiny tube feet on their underside, powered by a water vascular system that pumps seawater through their bodies. You can often see and feel these tube feet in action at the touch tank.
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