Sea urchin is a member of Echinoderm family
The classification of a Sea Urchin is Echinoidea
sea urchin
A sea urchin does move, but not very frequently.
The scientific name for the watermelon sea urchin is "Strongylocentrotus droebachiensis."
because the crab needs the sea urchin for protection and the sea urchin needs the crab for food
Sea urchin belongs to the Animalia kingdom, Echinodermata phylum, Echinoidea class, Echinoida order, Strongylocentrotidae family, Strongylocentrotus genus, and purpuratus species.
Ummm...it's the thing from which a sea urchin hatches?
I think a sea anenome and a sea urchin can live together because i have a little aquarium and there is a sea urchin and and a sea anenome (if that's how you spell it) living in there and they were perfectly fine. BUT if you have a sea urchin do not have any crabs in there, because my sea urchin killed one, and almost killed another one by taking its claw off. :(
a blue tuxedo sea urchin
It urges the sea to adapt to IT! The litle urchin urger.
Spines of the sea urchin can cause injuries of the skin.