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