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