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