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