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