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