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