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