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