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