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