Frilled Shark

Frilled sharks are eerie-looking deep sea sharks that resemble eels. They are named for the six gill slits on either side of the bodies, which are frilly-looking in appearance. These mysterious creatures are difficult to study, primarily because they live in the depths of the ocean and research is difficult to conduct at that depth. Part of the allure and mystery of this creature is that we know so little about it.  Read on to learn about the frilled shark.

Description of the Frilled Shark

These sharks have long, narrow bodies with long tails, and ribbon-like gill slits. They have multiple rows of sharp, needle-like teeth used for capturing slippery prey. Their pectoral fins are small, rounded, and located right behind the last gill slits. A single dorsal fin sits on the top of the back immediately before the caudal (tail) fin. They also have two thick skin folds located on either side of their abdomens.

Interesting Facts About the Frilled Shark

While we do not know everything about these elusive sharks, what we do know is simply fascinating. Learn what makes these creepy creatures so interesting below.

• Elusive Creatures – Though these sharks were first described in 1884, from specimens captured off the coast of Japan, they are not easily studied. In fact, the first footage of a frilled shark in its natural habitat was not recorded until 2004.
• Snake-Like – Their elongated body gives them an eel or snake like appearance, this is reflected in their species name anguineus or “consisting of snakes.” The similarities don’t stop there, scientists believe these predators hunt in similar fashion as well.
• Striking! – Though they haven’t been seen or recorded while hunting, their elongated body and fin positioning suggests that the hunt by launching themselves at their prey. This would look quite similar to a snake striking.
• Long Wait – Another suspected but unproven tidbit about these sharks is their estimated gestation period. Scientists estimate that the gestation period of this species could be as long as 42 months, making it the longest in the world! This lengthy gestation could be due to the cold temperatures of their natural habitat in the deep sea.

Habitat of the Frilled Shark

These predators live primarily on the continental shelf, and the deeper continental slope. They can be found anywhere from 160 ft. to 5,150 ft. below the surface, but most commonly between 160 and 660 ft. deep.

For the most part they are spotted at or near the sea floor, but researchers believe they participate in vertical migration. This means that they swim towards the surface to feed on prey that migrates upwards at night.

Distribution of the Frilled Shark

Researchers believe that these sharks have very fragmented and spotty distribution. They are found in pockets of suitable habitats across the Atlantic and Pacific oceans.

Populations or specimens have been located off the coasts of Norway, France, Scotland, Ireland, the Mid-Atlantic Ridge, Africa, Brazil, and the United States in the Atlantic. In the Pacific they have been sighted near Japan, Taiwan, Australia, Hawaii, the United States, and Chile.

Diet of the Frilled Shark

These sharks have very long jaws and are capable of distending them to engulf surprisingly large prey. They can consume creatures up to half their size, but this ability keeps them from having bite strength comparable to other sharks. Some common prey includes octopus, squid, bony fish, and smaller sharks.

Research suggests that, at least in some populations, squid can make up over half of this species’ diet. Squid are extremely swift creatures, so scientists speculate that frilled sharks are able to capture them by curving their bodies and striking forward like a snake.

Frilled Shark and Human Interaction

These sharks rarely interact with humans. Though they aren’t quite as inaccessible as other deep-sea species, like vampire squid, they aren’t exactly swimming distance. Most individuals that are viewed at the surface alive die quickly.

There are a few commercial fisheries that accidentally catch these sharks, particularly bottom trawlers, gillnets, and longlines, but these catches are minimal. There is minor danger to the sharks because they have such a long gestation and fragmented population pockets, but they are considered to be Least Concern by the IUCN Red List.

Domestication

Frilled sharks have not been domesticated in any way.

Does the Frilled Shark Make a Good Pet

No frilled shark has survived in an aquarium for longer than a few hours.

Frilled Shark Care

Little is known about frilled shark care, because they have not been held in an aquarium successfully. They have very particular care needs, and individuals at the surface rarely survive longer than a few hours.

Care would have to include a tank similar in temperature, oxygen, and salinity, to their deep-sea habitat. Diet would be variable based on the natural location, but would likely consist of squid and small fish.

Behavior of the Frilled Shark

These sharks have extremely large livers with high levels of lipids, and a low level of calcification in their skeletons. This makes them extremely buoyant, and in the depths of the ocean they have neutral buoyancy. Neutrally buoyant creatures are able to float in the water column with little to no effort.

When night falls, their primary prey, squid, rise towards the surface of the ocean. Frilled sharks follow their prey upwards to hunt at night, and move back to the depths during the day, this is called vertical migration.

Reproduction of the Frilled Shark

While little is known about the reproduction of these sharks, scientists are able to speculate based on specimens accidentally captured by fishermen. It is possible that they aggregate in relatively large numbers to breed, possibly around a dozen individuals. Litters contain six young sharks, called “pups,” on average. Scientists believe that it takes 42 months (over three years) for the young to develop fully.

Beliefs, Superstitions, and Phobias About the Frilled Shark

Some researchers speculate that frilled sharks are the source of sea serpent mythology. These creatures have an elongated body, objectively terrifying appearance, and serpent-like movements. Further, longer specimens may have existed, and other species of great lengths are present in the fossil record.