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