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