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