29/07/2026
A starfish doesn't have blood.
Instead, it pumps seawater through its body.
A network called the water vascular system uses seawater to move nutrients, transport oxygen and even power the tiny tube feet that help the starfish crawl, grip rocks and pry open shellfish.
In other words, every step it takes is driven by water pressure.
It's one of the most unusual body systems in the animal kingdom.
The next time you see a starfish slowly moving across the seafloor, remember...
It's walking on hydraulics.