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