球海胆属

Strongylocentrotus purpuratus is not the primary subject of the video clip; the primary subject is Asterina miniata (Bat star). Eastern North Pacific Ocean, Duration 31 seconds

Kattegatcentret Grenå

Scleractinia, Porifera

Kattegatcentret Grenå

Kattegatcentret Grenå

Kattegatcentret Grenå

Kattegatcentret Grenå

Øresundsakvariet

Scleractinia, Porifera

Scleractinia, Porifera

Aboral (top) surface of purple urchin showing anus surrounded by spines, pinchers, and tube feet.

Closeup showing the urchin's chewing apparatus, 'Aristotle's lantern.'

Skeleton of purple urchin shows convex points of attachment of spines and openings for branches of the water vascular system that serve the tube feet.

Depth 24 m. For about two years, purple urchins denuded a localized patch of sea floor at moderate depth. We do not know why the sea otter did not prevent this localized catastrophe.

with sea star

Porifera, Nudibranch?

The purple sea urchin, Strongylocentrotus purpuratus, lives along the eastern edge of the Pacific Ocean.