12/08/2026
🌊 Cool sea urchin facts:
• They have teeth! 🦷
Sea urchins have five tiny, self-sharpening teeth in a structure called Aristotle’s lantern. They use them to scrape algae off rocks.
• They can “walk” on hundreds of tiny feet. Their tube feet are operated by a water-based hydraulic system and help them move, cling to rocks and even capture food.
•Their spines aren't just for defence. They also help with movement and can sense their surroundings.
•Some sea urchins can live for decades. Certain species, particularly the red sea urchin, can live 100 years or more.
•They are important for kelp forests. Sea urchins eat algae and kelp, helping keep marine ecosystems balanced. Too many urchins, though, can contribute to “urchin barrens” where kelp disappears.
•They don't have a brain. 😮 Instead, they have a nervous system spread through their body, allowing them to respond to their environment.
•They come in some amazing colours. Depending on the species, you can find purple, red, green, black, orange and even pale urchins. 💚
•Their shape is surprisingly perfect. Most regular sea urchins have five-part radial symmetry - you can often spot the pattern if you look closely.
