20 Deep-Sea Monsters

Everyone knows about aliens and zombies, but they are only stories, and there is no reality about them. Maybe in future, but not yet. However, there are many terrifying creatures in the world, and we don’t know about them. If we talk about marine animals, there are hundreds of marine monsters are living in the world’s oceans because most of them are in deep-sea levels. Scientists and researchers have been described some of these monsters and briefly. So we have collected information about twenty such deep-sea monsters that are present in all large oceans.


Fangtooth are beryciform fish that live in the deep sea. Fangtooths are inhabitants of tropical and cold-temperature waters. The family comprises only two similar species. These species are famous for their large, fang-like teeth. However, they are very small and harmless to humans. The maximum length of a Fangtooth is just 16 cm. The head of Fangtooth is small with a large jaw and appeared riddled with mucous cavities. They eyes are very small, and the entire head is a dark brown to black. It has the largest teeth of any fish in the ocean, so large that it can never close his mouth. The juveniles are quite different from the adults; they have long spines on the head, larger eyes, long and slender gill rakers, and smaller and depressible teeth. Fangtooths are the deepest living fish, found approximately 5000 meters down. They feed primarily by filtering zooplankton from the water, as well as target other fish and squid.

2Goblin Shark
Goblin Shark

The Goblin Shark is a rare species of deep-sea shark. They are sometimes known as “living fossil.” It is approximately three and four meters long when mature. They inhabit submarine, continental slopes, and seamounts throughout the world. Different anatomical features of the Goblin Shark just like small fins and flabby body suggest that it is sluggish in nature. They mostly hunt for teleost fishes, crustaceans, and cephalopods both near the sea floor and the middle of the water column. The long snout of Goblin Shark is covered with ampullae of Lorenzini that help it to sense minute electric fields of nearby prey, which it can catch up by rapidly extending its jaw. Deepwater fisheries catch a very small number of Goblin Sharks. Its large mouth is parabolic in shape, and the jaws can be extended almost to the end of the snout. It has long and narrow teeth. They mostly live in deep sea water deep as 1,300 meters. The last captured Goblin Shark was about 4 foot long and weighed about 7.5 kg.


The Viperfish is a species of marine fish. They are characterized by hinged lower jaws and long and needle-like teeth. A Viperfish can grow to lengths of 30 to 60 cm. It stays near lower depths, 80 to 1520 meters in the daytime and shallower depths at night. Mostly they attack prey after luring them within range with the help of light-producing organs named photophores, which are present along the ventral sides of its body. They flash their natural light on and off, at the same time moving their dorsal spine like a fishing rod and hanging completely in water. They also use the light-producing organ to potential mates and rivals. They vary in color from silver, green, to black. They use fang-like to immobilize prey. They would not be able to close their mouth due to teeth length. Moreover, Viperfish can undergo long periods with scarcely any food. They are believed to live from thirty to forty years in wild. However, in captivity, they live more than few hours. Some species of sharks and dolphins are prey upon them.

4The Black Swallower
The Black Swallower

Black Swallower is a species of deep-sea fish from the family Chiamodontidae. This species is popular for its ability to swallow fish larger than itself. Black Swallower has a worldwide distribution in tropical and subtropical water, in the bathypelagic and mesopelagic zones at a depth of 700 to 2,745 meters. It is most common fish of its genus as well as most common species in the North Atlantic. It is a small fish, with a maximum length of 25 cm. The body is compressed and elongated, without scales, and is a uniform brownish black in color. It has a long head, with a blunt snout, a large mouth, and moderately sized eyes. They mostly feed on bony fishes. Due to distensible stomach, it can swallow prey over twice its length and ten times its mass. They have found to have swallowed fish so large that they set in decomposition before digestion, so they release gasses forced the swallowers to the ocean surface. A Black Swallower with 19 cm length was found dead off Grand Cayman.

5Megamouth Shark
Megamouth Shark

The Megamouth Shark is a species of deepwater shark. It is one of three smallest extant planktivorous sharks, and the others are basking shark and whale shark. The first time they were discovered in 1976 when some species had been found dead. Sixty-one specimens were caught in April 2015. It is different from other sharks due to its large head with rubbery lips. Like the other filter-feeder, they swim with their mouth wide open filter water for jellyfish and plankton. It is the sole extant species in the distinct family Megachasmidae. Megamouth Shark has a brownish black color on top and has an asymmetrical tail with a long upper lobe. It is a poor swimmer and has a soft and flabby body. It is less active than the other filter-feeding sharks. They are large sharks and can grow up to 5.5 meters in length. Their weight up to 1,215 kg has been reported.

6Blue Ringed Octopus
Blue Ringed Octopus

The Blue Ringed Octopus are three octopus species that live in coral reefs and tide pools in the Indian and Pacific Oceans from Australia to Japan. Their main habitat is in northern Western Australia, South Australia, and New South Wales. They are one of the most venomous marine animals in the world. They have a small size, twelve to twenty cm, and relatively docile nature. Blue Ringed Octopuses are very dangerous to humans because their venom comprises tetrodotoxin, a neurotoxin powerful enough to kill humans. They mostly hunt shrimp, crabs, hermit crabs, and other small crustaceans. It pounces on its prey and seize it with its tentacles and pull it toward its mouth. Blue Ringed Octopuses are easy to identify due to their characteristic black and blue rings and yellowish skin. They spend much of their time hiding in crevices. They can quickly change color if provoked, becoming bright yellow. They swim by expelling water from a funnel in the form of jet propulsion.


Barreleyes or spook fish are small deep-sea fish from the family Opisthoproctidae. They are present in tropical-to-temperature waters from the Indian, Atlantic and Pacific Oceans. They are named Barreleye because of their barrel-shaped, tubular eyes. They have the capability to direct their eyes forward, as well. They have large, telescoping eyes. The toothless mouth is terminal and small, ending in a pointed snout. In all species, the fins are fairly small and spineless. However, the pectoral fins are elongated and wind-like. The standard length of Barreleye is at 50 centimeters. They inhabit moderate depths from 400 to 2500 meters. They are solitary and do not under diel vertical migrations. They use their sensitive and upward-pointing tubular eyes to survey the waters above. According to researchers, Barreleyes are pelagic spawners.


Snaggletooths or Stareaters are some small and deep-sea fish in the genus Astronesthes. They have delicate skin and mouths filled with needlelike, sharp, curved teeth. Snaggletooths possess a bioluminescent barbell that the deep-sea fish uses as a lure to attract small prey into striking distance. They are deep sea animals and considered as the monsters of deep waters due to their teeth and scariest mouth.


Rattails or Grenadier are large, black to brown gadiform marine fish from the family Macrouridae. They are present at great depths from the Arctic to Antarctic. They are easy to recognize due to their large heads with large mouths and eyes. They have slender bodies, and rat-like tail explains their common name “rattail.” The first dorsal fin is high, small and pointed, the second dorsal fin merges with the tail and extensive anal fin. They use their muscles to “strum” their gas bladders and produce, which play a courtship and mate location. Light producing organs, “photophores” are also present in some species. They are living at depths from 200 to 6,000 meters. They are the most common benthic fish of the deep. They form large schools, as with the roundnose Grenadier. The benthic species are attracted to structural oases, just like cold seeps, hydrothermal vents, and shipwrecks.  They mostly feed on shrimp, cumaceans, amphipods, and lanternfish.

10Marine Hatchetfish
Marine Hatchetfish

Deep-sea Hatchetfishes or Marine Hatchetfishes are small deep-sea ray-finned fish from the subfamily Sternoptychinae. These species are present temperature, tropical and subtropical water of the Pacific, Indian and Atlantic Oceans. They range in size from 2.8 cm to 12 cm. Marine Hatchetfishes are small deep-sea fishes which have a peculiar body shape. They use counter-illumination to escape predators that lurk in depth. Marine Hatchetfishes occur at a few hundred meters below the surface. However, their whole depth range spans between 50 to 1,500 meters deep. In some species of Deep-Sea Hatchetfishes, large sections of the body are transparent. They have blade-like pterygiophore and perpendicular spines in front of the dorsal fin. The anal fin has eleven to nineteen ray, divided into two parts. Their large eyes can collect the faintest of light and focus on objects both close and far.

11Dumbo Octopus
Dumbo Octopus

Dumbo Octopuses, Dumboes, or Dumbo Octopods are a genus of umbrella octopus that live in the deep sea. Ear-like fins protrude from the mantle above their lateral eyes. They have V or U shaped shell in their mantle for a bell-shaped appearance. Some species of Dumboes are short, yellow and squat; others resemble a jellyfish with one big walking shoe. In addition to spins, some have suckers on all eight webbed arms. There are approximately thirteen species, each with a different aspect from all the others. Some have larger ears or different colors. As they live at the bottom of the sea, they have a small food supply. They mostly prey on copepods, bivalves, worms and crustaceans. The average lifespan of different species is three to five years. Mostly, all species leave at extreme depths of 3,000 to 4,000 meters with some living up to 7,000 below sea level. So it is the deepest genus of any known octopus. The largest Dumbo Octopus recorded was 1.8 meters in length and weighed 5.9 kilograms. The average size is twenty to thirty centimeters.

12Pelican Eel
Pelican Eel

The Pelican Eel is a deep-sea fish. It is a rarely seen by humans. However, it is caught in fishing nets occasionally. This eel-like fish is the only known member of the genus Eurypharynx. This fish is closely related to the true eels in Anguilliformes. This type is also famous as Pelican gulper, gulper eel, and umbrella mouth gulper. Pelican Eel is also referred to the pelican because its large mouth is similar to that bird. The mouth of fish is larger than its body. Its mouth is loosely hinged and can swallow a fish much larger than the eel itself. The lower jaw is hinged at the base of the head. Gulper eels are black, but some subspecies have a thin lateral white stripe. Pelican Eels are ray-finned fish and resemble eels in appearance. It is different from other fish because it lacks swim bladders, pelvic fins, and scales. Their muscles have a “V-shape,” while other have “W-shaped” muscles. It has very small eyes as compared to other deep-sea creatures.  They can grow up to 0.75 meters in length. They mostly eat small crustaceans.


Anglerfish are bony fish named for their characteristic mode of predation. Some species of Anglerfish are notable for extreme sexual parasitism and sexual dimorphism of the small male on the much larger female. In Anglerfish species, males are much smaller than females in magnitude. They are present worldwide. Their color ranges from dark gray to dark brown. Their huge head that bear crescent-shaped mouth full of long teeth angled inward for efficient prey grabbing. The length of these species vary from 20 centimeters to over 1 meter with weights up to 45 kg. in 2005, Anglerfish was discovered near Monterey, California, at a depth of 1474 meters. It swam intermittently at the speed of 0.24 body lengths per second. Its name derives from its characteristic method of predation. They have one long filament sprouting from the middle of their heads, knows as the illicium. They mostly prey on teleost fish and crustaceans.


Amphipod is an order of malacostracan crustaceans. They range in size from 1 to 340 millimeters and are mostly scavengers or detritivores. They are marine animals but can be found in all aquatic environment. More than 1,900 Amphipod species live in fresh water. The body of this genus have thirteen segments, grouped into a thorax, head, and an abdomen. The head of Amphipod is fused to the thorax and contains two pairs of antennae and one pair of compound eyes. The abdomen and thorax are quite distinct and bear various kinds of legs. Typically, they are less than 10 millimeters in length. However, the largest living Amphipods were 28 centimeters long on the record. More than 9,950 Amphipod species are recognized currently, and they were places in the four suborders. Mostly, they are living in the southeastern North America, Mediterranean Basin, and the Caribbean.


Chimaeras, also known as ghost sharks, ratfish, rabbitfish, and spookfish are cartilaginous fishes in the order Chimaeriformes.  According to research, they are close relatives of sharks, and they branched off from the sharks nearly 400 million years ago. Now they are known as deep-sea creatures. They live in temperature ocean floors down 2,600 meters deep, with few at depths shallower than 200 meters. They have soft bodies with a single gill opening and a bulky head. Chimaeras can grow up to 150 cm in length. The snout is modified into a sensory organ in some species. Skeletons of Chimaera are constructed of cartilage. They have smooth skin, covered by placoid scales and their color can range from black to brownish gray. They don’t have replaceable teeth like sharks, but only three pairs of large permanent grinding tooth plates. Chimaeras have gills like bony fishes.

16Giant Isopod
Giant Isopod

A Giant Isopod is the marine animals of cold, deep water of Pacific, Atlantic, and Indian Oceans. This species is considered as the largest isopod in the world. They are of interest to most commercial fisheries due to many reasons. They are noted for resemblance to pill bug or woodlouse, to which they are related. The few Giant Isopods caught in the Japan and Americas with baited traps are seen in public aquariums. They are a good example of deep-sea gigantism, as they are far larger than the typical isopods. In Giant species, the adults are between eight and fifteen cm long and in “Supergiant” species, the adults are between 17 and 50 cm. The maximum weight and length of a Giant Isopod can be 1.7 kg and 76 cm respectively. Their bodies are compressed, protected by a calcareous exoskeleton made of overlapping segments. They have been recorded in the West Atlantic from Georgia to Brazil.


The Stargazers are from the family Uranoscopidae that have eyes on the top of their head. in addition to head, it has a large, upward-facing mouth. Their habit is to bury themselves in the sand and leaps upward to ambush prey that passes overhead. Some species of Stargazer have a worm-shaped lure, which they can wiggle to attract prey’s attention. Some species of Stargazer lack dorsal spines. Stargazers have two venomous spines located behind their opercles. Its specific species have a single electric organ comprising modified eye muscles. They are a delicacy in some culture, and they are present for sale in some markets with the electric organ removed. Some species of Stargazer can deliver both venom and electric shocks. Stargazers are known as “the meanest things in creation.” The length of Stargazers ranges from eighteen to ninety cm.


The Blobfish is a deep sea fish from the family Psychrolutidae. It lives in the deep sea water off the coast of Tasmania and Australia, as well as the waters of New Zealand. They live at depths between 600 and 1,200 meters where the pressure is sixty to one twenty times as great as at sea level. They are typically shorter than thirty centimeters. The flesh of the Blobfish is a gelatinous mass with a density less than water, which helps it to float above the sea floor without using energy on swimming. Blobfish lack of muscles and mainly swallows edible matter that floats in front of it just like crustaceans. They are caught as bycatch in bottom trawling nets. According to scientists, Blobfish could become an endangered species due to deep-ocean trawling. The Blobfish was voted the “Ugliest Animal of the World” in September 2013, based on images of decompressed specimens.

19Frilled Shark
Frilled Shark

The Frilled Shark is one of the two extant species of shark from the family Chlamydoseachidae. They have distribution in Pacific and Atlantic Oceans. They are present over the upper continental slope and outer continental shelf. Frilled Shark has been caught as deep as 1,570 meters. However, it is uncommon below 1,200 meters. Frilled Shark is most common at depths of 50 to 200 meters in Suruga Bay, Japan. This shark is termed as “living fossil” due to its primitive features. Frilled Shark reaches a length of two meters and has a dark brown body with pelvic, dorsal and anal fins placed far back. Its common name came from the frilly appearance of its six pairs of gill slits. It may capture prey by bending its body and lunging forward just like a snake. The flexible jaws enable Frilled Shark to swallow prey whole. Many rows of small and needle like teeth make it impossible for the prey to escape. They feed primarily on cephalopods, bony fishes, and other sharks.

20Vampire Squid
Vampire Squid

The Vampire Squid is small and deep-sea cephalopod in tropical oceans of the world. It shares similarities with both octopods and squid. This squid can read a maximum length of 30 centimeters. Its body varies in color from velvety black to pale reddish, depending on lighting conditions and location. It has eight arms, each with rows of fleshy spines or cirri. Only the distal half of the arms have suckers. It globular eyes are the largest in the animal kingdom at 2.5 centimeters in diameter. Its dark color and red eyes give it the name of Vampire Squid. However, it does not feed on blood. It is an extreme example of a deep-sea cephalopod. It resides at aphotic depths from 600 to 900 meters or more. They have been found among the stomach contents of deep-water fish such as giant grenadiers and marine mammals including sea lions and whales. They lack feeding tentacles and use two retractile filaments to capture food.