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