While they have no backbone, sunflower sea stars (Pycnopodia helianthoides) mean business–especailly when faced with spiny sea urchins. These 24-armed, roughly 3-feet-wide sea stars can move 40 inches per minute when on the prowl for crabs, snails, sea urchins, and other ocean creatures to eat. Since multiple species of sea urchins can wreak havoc on ecologically important kelp forests, understanding how natural predator-prey relationships like this one between urchins and sea stars could be used to protect kelp. Natural kelp forest guardiansPrevious research has found that increased sea otter populations have helped curb urchin populations around kelp forests. A sunflower sea star was placed in one cage, while the other was sea star free.