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