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