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