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