Toothpick
Pentamerous
Dome
Porcupine
Algae
Sea cucumbers
Other sea urchins
Small fish
Subtidal area only
Both intertidal area and subtidal areas
Intertidal area only
On the beach
Because sea urchins have large numbers of relatively big eggs
Because a sea urchin's egg is relatively big
Because sea urchins have large numbers of eggs
Because the eggs make great omlettes
Spine
Nose
Mouth
Feet
Purpuratus
Strongylocentrotus
Animalia
Echinoderms