The front teeth grasp, while the back rows lie flat and grind. Horn sharks eat sea urchins and crustaceans, grinding away their spines and crushing their shells. The shark's curved nostril-flaps channel water into its nose so the shark can smell. The female lays a spiral egg case in which a single shark grows, nourished by yolk. Giant kelp plants wrap a rootlike holdfast firmly around rocks on the bottom and send out a central stipe that can grow 100 feet up and another 30 feet along the surface.
Blades grow off the central stipe, each with an air bladder that helps keep the plant afloat.
Like rainforests, kelp forests offer food and refuge to an array of species at every level, from the bottom to the canopy. Though kelp is sometimes torn up by winter storms, it regrows quickly-as much as 14 inches in a day.