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