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