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