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