moomz
/vs·animals·en

Starfish vs Sea urchin🥋

Starfish and sea urchins are close relatives in the echinoderm family, yet they look nothing alike. One has arms, the other a spiny ball.

Run a moomz poll: who wins for you?
moomz.com — 10s, anonymous, free
Starfish
  • Distinctive star shape with several arms
  • Can regenerate lost arms
  • Pries open shellfish to feed
  • Moves on hundreds of tiny tube feet
🥋Sea urchin
  • Round body covered in protective spines
  • Grazes algae from rocks and reefs
  • Spines deter most would-be predators
  • Uses a five-toothed mouth called Aristotle's lantern

Verdict

The starfish is the iconic armed predator; the sea urchin is the round spiny grazer. Both are echinoderms moving on tiny tube feet.

Frequently asked

Are starfish and sea urchins related?+

Yes, both are echinoderms, the group that also includes sea cucumbers and sand dollars.

Can a starfish regrow an arm?+

Yes, many starfish can regenerate a lost arm, and some can regrow from a single arm.

What do sea urchins eat?+

Sea urchins mainly graze on algae and seaweed using a five-toothed mouth.

Also in

More in animals

Run a moomz poll: who wins for you?