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sea urchin
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Introduction References & Edit History Related Topics
Images & Videos
Slate-pencil urchin (Heterocentrotus mammillatus)
What is a trophic cascade?
Deuterostomia invertebrates details of a tube foot of a sea urchin
Watch how a queen triggerfish defeats a sea urchin's defensive tactics
See how sea creatures have evolved different adaptations to both catch prey and avoid becoming prey
How sea otters preserve their ecosystem
Quizzes
Sea otter (Enhydra lutris), also called great sea otter, rare, completely marine otter of the northern Pacific, usually found in kelp beds. Floats on back. Looks like sea otter laughing. saltwater otters
Animal Group Names
Lion (panthera leo)
Deadliest Animals Quiz
Mute swan with cygnet. (birds)
Match the Baby Animal to Its Mama Quiz
vulture. An adult bearded vulture at a raptor recovery center. The Gypaetus barbatus also known as the Lammergeier or Lammergeyer, is a bird of prey and considered an Old World vulture.
Animal Factoids
Discover
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News •

Coral reefs can’t survive rising sea urchin numbers • June 2, 2025, 12:36 AM ET (Earth.com)

Photos and Videos

Slate-pencil urchin (Heterocentrotus mammillatus)
Deuterostomia
invertebrates
details of a tube foot of a sea urchin
What is a trophic cascade?
Watch how a queen triggerfish defeats a sea urchin's defensive tactics
See how sea creatures have evolved different adaptations to both catch prey and avoid becoming prey
How sea otters preserve their ecosystem
See All Videos and Images →

Related Topics and References

Topics

Related Quizzes and Features

Quiz
Sea otter (Enhydra lutris), also called great sea otter, rare, completely marine otter of the northern Pacific, usually found in kelp beds. Floats on back. Looks like sea otter laughing. saltwater otters
Animal Group Names
Mute swan with cygnet. (birds)
Match the Baby Animal to Its Mama Quiz
vulture. An adult bearded vulture at a raptor recovery center. The Gypaetus barbatus also known as the Lammergeier or Lammergeyer, is a bird of prey and considered an Old World vulture.
Animal Factoids
Lion (panthera leo)
Deadliest Animals Quiz