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