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