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