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