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