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