Humans rarely encounter frilled sharks, which prefer to remain in the oceans' depths, up to 5,000 feet (1,500 meters) below the surface. Considered living fossils, frilled sharks bear many physical characteristics of ancestors who swam the seas in the time of the dinosaurs. This 5.3-foot (1.6-meter) specimen was found in shallow water in Japan in 2007 and transferred to a marine park. It died hours after being caught.
The common octopus is anything but ordinary. This most intelligent of the invertebrates uses an amazing suite of abilities to avoid predators like sharks, eels, and dolphins. A master of camouflage, the octopus can change color and shape to remain unseen, and release a “smoke screen” of black ink when spotted. Even if an octopus has been nabbed, the game isn’t over—it can simply shed an arm to escape trouble and regrow the appendage later.