Large eyes and lots of tentacles are two clues that chambered nautiluses are kin to octopuses, squids and cuttlefish. They are the sole cephalopods (or “head-footed” animals), however, encased in a shell. And an amazing shell it is. What to us are striking stripes are for the nautilus cryptic coloration that enables it to blend into the dark waters of the deep reef. The shell also allows this animal to vertically traverse the reef between about 300 and 1,500 feet. As its name indicates, the nautilus builds a chambered shell, always living in the newest, largest “room.” It can control its buoyancy by pumping water into the chambers to sink to relatively predator-free depths or by pumping out the water and filling the chambers with gas to occasionally ascend at night to feed on small fish, shrimp and crustaceans closer to the surface. It can also actively swim by jet propulsion, blowing water in and out of its mantle with a siphon. Either way, a heavy-shelled nautilus moves slowly. Shedd’s nautiluses are frequently anchored to a reef wall in the nocturnal habitat of Wild Reef.