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