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