Crown-of-Thorns Sea Star
Acanthaster planci
40 cm

Where Crown-of-Thorns Sea Stars are found. Map from GBIF.
Count Log
You have not counted me yet. Visit the South Reef or North Reef , grab a tricoder, and click on me!

Encyclopedia of Life
Visit this species on the Encyclopedia of Life to find out more!
I am an echinoderm. Echinoderm means "spiny skin". The sea urchins on WhyReef are also echinoderms, but they don't have long arms and look more like pin cushions. I am way cooler, especially when I crawl around on the reef using my tube feet. I have hundreds of these little tube feet on the bottom of my body. I can only see changes between light and dark, my eyes don't see in color and they don't pick out shapes. But, I have an eyespot and the end of each of my arms --this means I can see in front, to the sides and behind me all at once! It's awesome!
Fun Facts
Don't call me a starfish. I am a Sea Star...and I am one of the largest ones on the reef! I can grow to almost 16 inches (40cm) across. I also have sharp spines to protect me from predators and I can have up to 19 arms, so I am WAY more ferocious than those other 5-armed (puny!) sea stars. I usually win my fights, but some times I lose arms in my epic battles with other reef creatures. When that happens, I just re-grow it! This is something that all sea stars can do.
I only eat other animals, so I'm a carnivore. But I only eat one kind of animal: corals! Corals are soooo very tasty, but most Whyvillians think my table manners are gross. I don't get it; all I do is spit out my stomach onto the coral, digest the coral outside of my body and then I suck up the liquid. That's not gross, right?
I can be dangerous to a reef. I can eat entire coral colonies, and I am always hungry. All by myself I can eat 13 square miles (33.7 sq km) of coral a year! If there are too many of us on a reef we can destroy it. Have you played the mini-Food Web Game with me in it? You can find out who eats me!