Nose
Spine
Feet
Mouth
Algae
Other sea urchins
Sea cucumbers
Small fish
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
Purpuratus
Echinoderms
Animalia
Strongylocentrotus
Subtidal area only
On the beach
Intertidal area only
Both intertidal area and subtidal areas
Dome
Pentamerous
Toothpick
Porcupine