The Common Starfish — more accurately called a sea star since it is not a fish — is one of the most recognizable invertebrates of European Atlantic and North Sea coastlines. Operating an extraordinary hydraulic locomotion system involving hundreds of suction-cupped tube feet, it is also a voracious predator of bivalves that can evert its entire stomach outside its body to digest prey in situ. Sea stars are among the most regenerative animals on Earth, capable of regrowing entire lost arms and, in some species, regrowing a complete body from a single severed arm.
About the Starfish
Asterias rubens
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⚡ Speed Comparison
📸 Photo Gallery
💡 Fun Facts
01
Starfish can evert their cardiac stomach out through their mouth and insert it into a mussel shell gap as small as 0.1 mm to digest the bivalve externally.
02
They have no brain and no blood — instead of a circulatory system they use seawater pumped through a hydrovascular system to power all movement and organ function.
03
A sea star can regenerate a completely severed arm, and some species can regenerate an entire animal from a single arm fragment, a process taking over a year.
04
Starfish have eyespots at the tip of each arm that can detect light and dark, allowing them to orient toward darker crevices for shelter.
05
Sea stars played a key role in discovering 'keystone species' ecology: when ochre sea stars were removed experimentally from a tidal pool, mussel populations exploded and displaced nearly all other species.
📍 Where to Find This Animal
Habitat Types:
Rocky Intertidal & Subtidal
🛒 Starfish Related Gear
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