Sea stars, often mistakenly called starfish, are some of the most fascinating creatures we'll find beneath the ocean's surface.
We often see their star-shaped bodies, but there's so much more to learn about them. In this article, we'll share 10 amazing facts that might surprise you about sea stars!
1. No Brain, No Blood
It might sound strange, but sea stars have neither a brain nor blood. Instead of blood, they use filtered sea water to pump nutrients through their nervous system. This unique system helps them carry out all necessary functions, from movement to hunting.
2. Long Lifespan
Sea stars can live up to 35 years in the wild! They may seem fragile, but these creatures can survive for decades if conditions are right. Their long lifespan allows them to play an important role in their ecosystems for many years.
3. Starfish? Not Quite!
While most of us know them as "starfish," scientists prefer to call them sea stars. That's because they're not actually fish! Sea stars are closely related to sand dollars and sea urchins, and unlike fish, they lack gills, scales, or fins. So, next time you're discussing these ocean wonders, be sure to use the correct name!
4. 2,000 Species of Sea Stars
There are around 2,000 species of sea stars living in oceans around the world. These species thrive in various marine environments, from tropical regions to the chilly waters of the polar regions. No matter where you are, there's likely a sea star nearby!
5. Not for Freshwater
Despite their adaptability, sea stars cannot survive in freshwater. They need the saltwater of the ocean to live and thrive. Freshwater would disrupt their delicate systems, making it impossible for them to survive.
6. Regeneration Powers
One of the most fascinating features of sea stars is their ability to regenerate lost limbs. If they lose an arm, it can take up to a year for it to grow back. This incredible power ensures that they can survive and continue to thrive in their environment, even after an injury.
7. They Eat Inside Out
Sea stars have a unique way of eating. When they catch their prey, they use tiny suction cups on their arms to grab onto it. Then, they push their stomach out through their mouth to digest the food externally. Once the food is fully digested, their stomach reenters their body. It's a remarkable process that allows them to consume their meals efficiently.
8. Two Ways to Reproduce
Sea stars are versatile when it comes to reproduction. They can reproduce sexually, where males and females release reproductive cells and eggs into the water. This fertilization process creates swimming larvae that eventually settle on the ocean floor. But sea stars can also reproduce asexually, by regenerating lost parts, like limbs.
9. Meet the Brittle Stars
Brittle stars are closely related to sea stars and are often mistaken for them. While they look similar, brittle stars are different. These cousins of sea stars have long, flexible arms and tend to live in deeper ocean habitats. You'll find them in tropical, temperate, and even polar waters.
10. Sea Stars Can Have Up to 40 Arms!
While most sea stars have five arms, there are species that have much more. For example, the sun star can have up to 40 arms! This makes them one of the most unique species in the starfish family, with their many arms giving them a star-like appearance.
A Marvel of Nature
From their amazing regeneration skills to their ability to live in various environments, sea stars truly are wonders of the ocean. These fascinating creatures remind us how incredible the natural world is and how much there is still to learn beneath the sea. We hope these 10 fun facts have given you a deeper appreciation for sea stars and their role in marine life!
