Top 15 Extraordinary and Mysterious Deep Sea Creatures

The depths of the oceans are often seen as the final unexplored frontiers on Earth. Each year, we uncover hundreds of previously unknown species, ranging from minute crustaceans to giant fish, with countless others still waiting to be discovered. Here are 15 of the most fascinating deep-sea inhabitants.

15. Ocean Sunfish

The ocean sunfish (Mola mola) holds the title of the heaviest bony fish in existence, with an average weight of about 1000 kilograms. This remarkable species is found in tropical and temperate waters across the world.

The Megamouth Shark is an exceptionally rare and unusual deep-water species. First discovered in 1976, only a handful of these sharks have been observed, with 39 specimens either caught or sighted by 2007, including three filmed instances. Similar to the basking shark and whale shark, it feeds by filtering plankton and jellyfish through its vast open mouth.

This peculiar cartilaginous fish uses its elongated snout to sweep across the ocean floor, detecting the electrical signals of buried prey, much like how a metal detector works.

Also known as the ogrefish, the fangtooth has earned its name due to its large, fang-like teeth and intimidating appearance. However, these fish are actually quite small and pose no threat to humans. The larger species, the common fangtooth, grows up to just 16 centimeters (6 inches), while the shortthorn fangtooth is about half that size.

The pelican eel is most recognized for its massive mouth, which is disproportionately large compared to its body. Its jaw is loosely hinged, allowing it to open wide enough to engulf prey much bigger than itself. The shape of its lower jaw, which resembles a pelican’s, is what gives this eel its name.

The blue-ringed octopus, despite being the size of a golf ball, carries venom potent enough to be lethal to humans. There is no known cure or antidote for its bite.

With its terrifying grin, reminiscent of a creature from a horror movie, the viperfish is a genuine predator that resides in some of the most isolated corners of the ocean.

This large species features a rounded head and a forward-facing mouth designed to capture squid and fish that rise from the ocean floor. Like other rattails, the males possess a unique drum-like mechanism within their swim bladder, which they use to attract females.

The Vampire Squid is entirely covered in light-producing organs known as photophores. This creature has remarkable control over these organs, enabling it to produce brief or prolonged flashes of light, from fractions of a second to several minutes.

With its polka-dotted mantle and wide-eyed look, this glassy creature offers a glimpse of the lighter, more whimsical side of the deep ocean.

5. Giant Squid

The mysterious giant squid, scientifically named Architeuthis dux, is among the largest creatures on Earth, growing up to 60 feet in length. It holds the title of the world's largest known invertebrate.

4. Giant Isopod

These creatures are believed to be plentiful in the cold, deep waters of both the Atlantic and Pacific Oceans.

3. Football Fish

This species is renowned as the first deep-sea anglerfish ever discovered. The initial specimen was found washed up in Greenland in 1833; at 22 inches long, it remains the largest one recorded. Since no females have ever been found carrying parasitic males, scientists speculate that they are fertilized by free-swimming males.

2. Pacific Blackdragon

Female blackdragons typically grow to about two feet (61 cm), featuring fang-like teeth and a long chin whisker. The males, however, are much smaller, only about three inches (8 cm) long, and have a brownish hue. They lack teeth, chin barbels, and even a stomach. The male's sole purpose is to mate, as it cannot eat and lives only long enough for reproduction.

1. Amphipod

The remarkable creature known as Phronima, an Amphipod, is among the many fascinating species recently discovered during an expedition to a deep-sea mountain range in the North Atlantic.