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