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