Also known as spook fish, these strange looking creatures are similar to hatchetfish in that they have two upward facing eyes to scan for prey. The Barreleye is the only vertebrate known to use a mirror (as well as a lens) in its eyes for focusing images. Their distinctive feature, however, is the transparent dome that encases them. They live as deeo as 2,500 m (8200 ft).
The Black Swallower
The black swallower is a small fish, with a maximum known length of 25 cm (9.8 in). Also known as the great swallower, the capacity of this little monster to engulf and digest things significantly larger than itself should not be underestimated. In fact, it can consume prey over 10 times its own mass. It has a worldwide distribution in tropical and subtropical waters, in the mesopelagic and bathypelagic zones at a depth of 700–2,745 m (2,297–9,006 ft).
Primarily found in the deep water off of Australia and New Zealand the Blobfish normally live at depths between 600 and 1,200 m (1968 to 3937 ft) where the pressure is 60 to 120 times as great as at sea level. The flesh of the Blobfish is primarily a gelatinous mass with a density slightly less than water. Because of that, the fish is allow to float above the sea floor without expending energy on swimming. Its relative lack of muscle is not a disadvantage as it primarily swallows edible matter that floats in front of it such as deep-ocean crustaceans.
Unlike the other creatures on this list, the Isopod is permanently constrained to creeping along the bottom of the ocean, primarily the cold, dark waters of the North Atlantic and the Arctic Circle. The Giant Isopod reaches an average length between 19 and 36 centimetres (7.5 and 14.2 in) and the depth record for any giant isopod is 2,500 metres (8,200 ft). They are scavengers.
The Pacific viperfish has jagged, needlelike teeth so outsized it can’t close its mouth. These deep-sea demons reach only about 8 inches (25 centimeters) long. They troll the depths up to 4,400 m (13,000 ft) below, luring prey with bioluminescent photophores on their bellies.
Humans rarely encounter frilled sharks, which prefer to remain in the oceans’ depths, up to 5,000 ft (1,500 m) 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.
Thought to be the largest arthropods on Earth, giant spider crabs spend their time foraging on the ocean floor up to a thousand feet (300 meters) deep. These rare, leggy behemoths, native to the waters off Japan, can measure up to 12 feet (3.7 meters) from claw tip to claw tip. This five-foot (1.5-meter) specimen was photographed in Japan’s Sagami Bay.
The sinister-looking Atlantic wolffish makes its home in the rocky coastal depths up to 1,600 feet (500 meters) below. Reaching 5 feet (1.5 meters) long, wolffish have conspicuous dentition suited to a diet of hard-shelled mollusks, crabs, and sea urchins. This mated pair was found in a deep-sea den off the coast of Maine.
The nightmarish fangtooth is among the deepest-living fish ever discovered. The fish’s normal habitat ranges as high as about 6,500 feet (2,000 meters), but it has been found swimming at icy, crushing depths near 16,500 feet (5,000 meters). Fangtooth fish reach only about six inches (16 centimeters) long, but their namesake teeth are the largest, proportionate to body size, of any fish.
Crushing pressure, freezing temperatures, and zero sunlight isn’t enough of a challenge for giant tube worms. They’ve adapted to thrive at the edge of hydrothermal vents, which spew superheated water saturated with toxic chemicals. This colony was photographed 1.5 miles (2.4 kilometers) below the ocean’s surface on the East Pacific Rise near the Galápagos Islands.
Vampire squid is an apt name for a creature that lurks in the lightless depths of the ocean. Comfortable at 10,000 feet (3,000 meters) below the surface, these diminutive cephalopods navigate the blackness with eyes that are proportionately the largest of any animal on Earth. The species gets its name from its dark, webbed arms, which it can draw over itself like a cloak. It occupies the mesopelagic and bathypelagic regions of temperate and tropical world oceans. The animal’s physiology has adapted to enable it to live at the very low oxygen levels found within the oxygen minimum layers of these regions.
A brightly colored clown frogfish shows off its stuff on a reef near Bali, Indonesia. Members of the frogfish family typically keep a much lower profile, relying on the art of camouflage—even changing colors—to stay hidden in their reef homes. Frogfish boast an array of stripes, spots, warts, and other skin anomalies that allow them to impersonate surrounding rocks or plants.
An almost surreal seafloor tableau unfolds in the shallow waters of Long Sound, New Zealand. A colorful blue cod picks its way through a sparse assemblage of sea pens—named for their resemblance to old-time quill writing implements. Sea pens are actually colonies of tiny, tentacled polyps, which form “branches.” They are rooted to the seafloor by an anchoring bulb—which can serve as sanctuary for the entire colony when threatened.
A sea cucumber floats in the waters of Bikini Atoll, once home to a series of infamous nuclear bomb tests. These echinoderms can grow to 6.5 feet (two meters) by feeding on tiny aquatic animals, algae, and even waste material. Sea cucumbers recycle food particles into fodder for bacteria much like worms do in soil. Though they are fairly simple animals, sea cucumbers do have one incredible defense mechanism—the ability to eject internal organs out of their anus and regenerate them later.
An alert anglerfish swims in the cool, dark waters near Norway’s Lofoten Islands. The fish has saggy skin and a distinctive face but is best known for its method of feeding itself. While cruising the seafloor, the fish uses a built-in rod with a tempting filament “lure” that attracts small fish.
The Dumbo octopus, named for its pair of prominent fins, is much smaller than its elephant namesake—it’s only about 8 inches (20 centimeters) long—and dwells near the ocean floor at depths of up to 1,310 feet (400 meters). Like other octopuses, it has eight arms, but they are webbed and serve as swimming aids, supplementing the flapping of the giant fins.
Eastern Fiddler Ray
The eastern fiddler ray is an Australian original that haunts the south coastline’s sandy bays and reefs to prey on shellfish and other seafloor invertebrates. The ray, which can grow to 4 feet (1.2 meters), can be spotted by the triangular markings behind its eyes—part of the distinctive coloring and shape that have earned this animal the nickname “banjo shark.”
At less than 5 inches (11 centimeters) long, the giant hatchetfish isn’t the behemoth its name suggests, but it does have some big league abilities. The deep-sea dweller boasts a row of light-producing organs lined up along its belly, the “blade” on its hatchet body. These bioluminescent organs shine like daylight from above the ocean surface, creating counterillumination to confuse predators that strike dark silhouettes from below. Hatchetfish swim in temperate and tropical seas all over the world.
This photogenic fish has red lips and fins made for walking the seafloor near the Galápagos Islands. The red-lipped batfish is one of some 60 species of batfishes, “flattened” from life on the seafloor and adapted to walk on modified pectoral and pelvic fins. Like other anglerfishes, batfishes also use a built-in fishing rod snout, equipped with a retractable appendage, to lure prey close to their lips—which, by the way, appear far less conspicuous without a photographer’s flash.