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