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