Both intertidal area and subtidal areas
On the beach
Intertidal area only
Subtidal area only
Animalia
Strongylocentrotus
Echinoderms
Purpuratus
Because the eggs make great omlettes
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
Feet
Nose
Spine
Mouth
Porcupine
Toothpick
Dome
Pentamerous
Sea cucumbers
Other sea urchins
Algae
Small fish