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