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