Saw sharks and frilled sharks and ghost sharks, oh my! All sharks are pretty wild in one way or another—but these sharks might just be the wackiest of them all. With extendable jaws, poisonous flesh, and a dazzling array of adaptations ranging from glowing eyes to glowing underbellies, these sharks showcase the remarkable ways marine predators have evolved to survive in the ocean. Wonderful as they are, many of these sharks are threatened by accidental fishing and habitat destruction, which means there is a chance they will disappear before we even get to know them. Click on through for a weird, wacky, and wonderful ride!
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Weird, Wacky, Wonderful Sharks
Dwarf Lantern Shark
Credit: © Chip Clark/Smithsonian InstitutionThe smallest shark, a dwarf lantern shark (Etmopterus perryi) is smaller than a human hand. It's rarely seen and little is known about it, having only been observed a few times off the northern tip of South America at depths between 283–439 meters (928–1,440 feet). The specimen pictured here was discovered in the Caribbean Sea off the coast of Colombia in 1985 at a depth of 290 m (950 ft).
Like other lantern sharks, the dwarf lantern shark has light-emitting organs called photophores along its belly and fins. These help them camouflage when they feed in shallower water: the lit-up belly blends in with sunlight streaming down from above. In darker water, the light attracts smaller animals, which the shark preys upon. It also has big eyes (for a shark) to help it see in the mostly-dark waters of the ocean's twilight zone.
Frilled Shark
Credit: Citron, Wikimedia Commons
Is it an enormous eel? No—it's a shark! The frilled shark is named for its strange appearance, including a snakelike body, three pronged teeth, and gills that give the impression of a frilly collar. However, this collar does not mean these sharks are dainty eaters. Even though their feeding behavior is yet to be observed, some scientists believe that their flexible jaws could allow them to swallow prey whole that is up to half the frilled shark’s size!
Cookie Monster of the Sea
Credit: Jennifer Strotman, Collections ProgramI want snack, so give me cookie! The cookie cutter shark (Isistius brasiliensis) is as fearless as they come! This small, 20-inch shark can take on giants like whales and larger sharks, and have even been known to mistakenly try to bite submarines. They dwell in the deep warm ocean and come closer to the surface as the sun sets to grab a quick snack off their unsuspecting prey. Cookie cutter sharks approach their victims from below, latch on with their suction cup style lips, bite and then twist. A nice, round hole is left as a souvenir. They get this easy meal by tricking other ocean residents with their distinctive brown collar, which may act as a lure that allows the cookie cutter shark to be seen as a smaller, not-so-scary fish. As frightening as they seem, they do not pose a threat to humans.
The Goblin Shark
Credit: Dianne Bray / Museum VictoriaThe goblin shark (Mitsukurina owstoni) is one of the creepier fish out there! It has a long, prominent snout covered with special sensing organs (ampullae of Lorenzini) that help it to sense electric fields in the deep, dark water it calls home. It also has unusual coloration, ranging from pinkish to purplish grey, with bright blue around the edges of its fins. But even stranger is its jaw. Though close to the head in this picture, it can be extended to the length of its snout to help the goblin shark ambush fish, squids and crustaceans. In fact, different preserved specimens of goblin sharks were once incorrectly classified as separate species because their jaws stuck out at different lengths. See more photos of scary ocean creatures in our slideshow.
Sawshark
Credit: OpenCageHow well could you eat with a saw on your face? If you were a sawshark, you couldn’t eat without one! Sawsharks are named for their long snouts, which have sharp teeth protruding from either side. They attack their prey by slashing these “saws” from side to side, cutting into the fish they intend to eat. Be careful not to confuse sawsharks with sawfish, which are actually a type of ray. Sawfish feed the same way, but are much bigger than the typical 5 feet (1.5 meters) length of a sawshark and have gills on the undersides of their heads rather than on either side.
Ghost Shark
Credit: NOAA Office of Ocean Exploration and ResearchWhen is a shark not a shark? When it’s a ghost shark! These creatures are actually chimaeras—cartilaginous fishes that are related to sharks but distinguished by several differences, including having only one gill on either side of the body. Inhabitants of deep water, chimaeras can grow more than six feet long depending on the species. Their eyes are backed with a reflective tissue layer that makes them seem to glow in the dark, contributing to an eerie—even ghostlike—appearance. This video gives you a rare glimpse of a ghost shark swimming around on a seamount.
Greenland Shark
Credit: Julius NielsonSwimming slowly through the freezing waters of the Arctic, Greenland sharks are among the world’s chilliest predators. They rarely move faster than 0.8 mph, and typically feast on fish, although they occasionally eat reindeer, polar bears and other mammals that fall through the ice above them. Their own flesh is toxic to humans because it contains high levels of trimethylamine oxide, an adaptation to living in the deep. But perhaps their coolest feature is their longevity – females are thought not to reach sexual maturity until 150 years, and the oldest known Greenland shark is also the oldest known vertebrate at 400 years old.