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