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