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