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