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What is a sea urchin?
Quick Answer
A sea urchin is a spiny marine animal related to sea stars and sea cucumbers. It grazes on algae and uses tube feet and spines to move and protect itself.
The Full Story
Sea urchins are echinoderms with a hard shell called a test and a covering of movable spines. They live on rocky shores, reefs, and seafloors, where many species graze on algae. Their teeth are part of a remarkable feeding structure known as Aristotle’s lantern. Some sea urchin populations can become very dense and strongly affect kelp forests and other marine habitats.
Key Facts
1.Have a hard shell called a test
2.Use an apparatus called Aristotle’s lantern to eat
3.Belong to the phylum Echinodermata
YouTube Angle
Suggested video title for this topic:
"The spiky seafloor grazer with a famous mouthpiece"
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