Algae
Sea cucumbers
Small fish
Other sea urchins
Pentamerous
Dome
Porcupine
Toothpick
Because the eggs make great omlettes
Because sea urchins have large numbers of relatively big eggs
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
Nose
Spine
Feet
Mouth
Purpuratus
Strongylocentrotus
Animalia
Echinoderms