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