Starfish, or sea stars, are truly strange creatures that probably don’t get much attention from most of us up on the surface. What even are they? And what do they eat? Are they even fish, anyway? In this fact file, we break it all down for you. Here are some fun facts about starfish you’ll want to keep in mind.
1. They are not actually fish!
Yes, the name is a complete misnomer – starfish are not technically fish! In fact, they are echinoderms. This means they are closely related to sea urchins and sand dollars.
2. They have a very unique shape.
Starfish are, of course, recognised by their distinctive shape. They have radial symmetry, typically featuring five arms, although some species can have even more. It is due to their five arms that they are, in fact, known as starfish.
3. They have superpowers, too.
One of the most interesting things about starfish is that they have incredible regenerative abilities! They can regrow lost limbs, and some species can regenerate an entire new body from just a single arm!
4. They have unique water vascular systems.
If you have ever wondered how starfish get about, they have a unique hydraulic water vascular system that helps them move and feed. This system uses seawater to create hydraulic pressure. This allows the starfish to extend and retract their tube feet, which they use for moving about and capturing prey.
5. They eat a great deal of different food!
Starfish eat a variety of things. Their diet includes small fish, mollusks, crustaceans, and detritus. They are known for their ability to pry open bivalve shells using their tube feet and then digest the soft tissues inside.
6. They don’t have brains.
No – seriously – starfish are one of many creatures to be officially “brainless!” Starfish do not have a centralized brain like many other animals. Instead, they have a complex nervous system, completely decentralized and interconnected throughout their bodies.
7. They have eyespots.
No – starfish don’t have eyes, either – as we know them, anyway! While starfish don’t have complex eyes like vertebrates, they do have eyespots located at the end of each arm. These eyespots can detect changes in light and help them navigate their environment.
8. Starfish can live all over the world.
Starfish can pretty much be found in a wide range of marine habitats. They can live anywhere from rocky shores and coral reefs to sandy bottoms and seagrass beds. They are distributed throughout the world’s oceans, from tropical waters to polar regions, making them pretty easy to find!
9. They come in all different kinds of colours.
One of the most beautiful things about starfish is that they come in a variety of colours and patterns, including vibrant hues of orange, red, blue, and purple. They’re not just yellow as you might expect! That expectation could be as a result of us associating the creatures with litreal stars!
10. They reproduce via eggs.
Starfish females release eggs into the water, and the males release sperm. Fertilisation, therefore occurs externally. Some species also have the ability to reproduce asexually through fragmentation or budding.
11. They have a lot of predators.
Starfish have a lot of predators including fish, birds, and larger invertebrates. To defend themselves, some species have spines or other deterrents, while others can detach limbs as a distraction or escape mechanism.
12. They can live for a long time!
Depending on the species, starfish can live for several years in the wild! In fact, some larger species can live up to 35 years or more. Of course, that all depends on whether or not they can avoid predators, too!
FAQs About Starfish
Is it OK to touch a starfish?
No, it is never a good idea to touch a starfish. Since they breathe through their outer bodies, it is never a good idea to handle them or to try and take them out of the water.
Are starfish harmful to humans?
Most species of starfish are not harmful to humans. However, crown-of-thorns starfish are very dangerous because their spines are venomous!
Can you eat starfish?
Yes, you can in fact eat starfish. However, if you’d like to try it, it’s best to consult a professional who can collect and prepare them properly.
Further reading
https://oceanservice.noaa.gov/facts/starfish.html
https://www.amnh.org/explore/ology/ology-cards/130-starfish
Do you know any fun facts about starfish? Share them in the comments below!