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