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