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