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