Spine
Feet
Mouth
Nose
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
On the beach
Both intertidal area and subtidal areas
Intertidal area only
Subtidal area only
Algae
Small fish
Sea cucumbers
Other sea urchins
Toothpick
Dome
Porcupine
Pentamerous
Animalia
Strongylocentrotus
Purpuratus
Echinoderms