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