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