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