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