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