Buzz
While many can identify popular shark species like the great white, tiger sharks, and the enormous whale shark, there's so much more beneath the surface waiting to be discovered.
Sharks come in a vast array of shapes and sizes, with about 440 known species today. This number continues to rise, with the recent discovery of the “Genie’s Dogfish” in July 2018.
Here are some of the most remarkable shark species uncovered to date.
10. Zebra Shark
Zebra sharks inhabit the western Pacific and Indian Oceans, as well as the Red Sea. Divers often confuse them with leopard sharks due to their similar black dots on a tan body. However, only mature zebra sharks exhibit this pattern, as younger sharks retain their yellow stripes.
With a highly flexible body that can easily maneuver into narrow spaces, along with whisker-like barbels on the front of its snout, the zebra shark is perfectly equipped to hunt in areas where other predators struggle to reach.
These sharks thrive in tropical waters and shallow reef environments. They primarily feed on crabs, sea urchins, small fish, snails, and other small invertebrates that seek refuge in caves and tight crevices.
In the absence of suitable mates, zebra sharks have been known to reproduce through parthenogenesis, also known as “virgin birth.” The reasons behind this spontaneous pregnancy remain unclear. For instance, in 2017, a zebra shark named Leonie laid eggs that hatched three pups, despite being without a male shark for three years.
Due to the high demand for its prized meat, zebra sharks face the threat of extinction in many of their native regions. They are sold both fresh and salt-dried in markets across Malaysia, Indonesia, the Philippines, and Thailand. Their livers are processed for vitamins, while their fins are frequently used in the popular Chinese delicacy, shark fin soup. However, the species remains abundant in Australia, where it is widely distributed and not subject to overfishing.
9. Megamouth Shark
Since its discovery off the coast of Hawaii in 1976, there have been only around 60 confirmed sightings of the megamouth shark. The species was so unique that it warranted the creation of a new genus and family. To this day, the megamouth shark is the sole member of the Megachasma genus. It holds the distinction of being the smallest and most primitive of the three sharks known to feed on plankton, alongside the basking shark and whale shark.
Megamouth sharks are known as 'vertical migrants,' constantly adjusting their depth based on the day-night cycle. During the day, they reside in deep waters ranging from 120–160 meters (390–525 ft) below the surface, and at night, they ascend to mid-depth waters of 12–25 meters (40–82 ft).
Because of the elusive nature of megamouth sharks, very little is known about their population and distribution. Most sightings have occurred in parts of the Pacific, Indian, and Atlantic Oceans, including countries such as Senegal, Indonesia, Brazil, and the Philippines. Some of the earliest discoveries were made along the coasts of Japan, Australia, and California.
With a mouth and jaws much larger than the rest of its body, the megamouth shark is not known for its swimming speed. To compensate, it has bioluminescent lips that glow in the dark, attracting prey in the deep waters where it spends most of its time. According to the Western Australian Museum, megamouth sharks also have flabby muscles, soft bodies, and weakly calcified skeletons, which prevent them from sinking.
8. Horn Shark
Horn sharks earned their name due to the prominent ridges above their eyes and the spines on their dorsal fins. They are also characterized by their wide heads, blunt snouts, and dark gray to light brown coloring, adorned with dark brown or black spots. Horn sharks are native to the subtropical waters of the eastern Pacific, particularly along the coasts of California, Mexico, and the Gulf of California.
Due to their small size, slow movements, and nocturnal hunting behavior, horn sharks are generally considered harmless to humans. However, they may bite if provoked. According to the International Shark Attack File, there is one recorded incident of a horn shark biting a human.
Currently, the horn shark population is not considered to be at risk. Humans do not commonly consume them and typically release them when caught as bycatch in trawls. However, this could change with the potential expansion of gillnet fishing in Mexico. Due to their manageable care, horn sharks are also frequently kept in both public and private aquariums.
In a strange incident, a horn shark was stolen from a Texas aquarium in July 2018. Surveillance footage showed three individuals using a stroller to steal the shark, disguising it as a baby. Later, an ad appeared online offering the shark for $300.
Two days after the theft, police located the truck involved in the heist and arrested one of the three suspects. He was charged with theft, and his bond was set at $10,000. The shark was found unharmed and was returned to the aquarium.
7. Spotted Wobbegong
The spotted wobbegong is one of twelve species of carpet sharks in the Orectolobidae family. The term 'wobbegong' is often used interchangeably with 'carpet shark.'
This shark earns its name from its flat, broad body, which helps it blend in and stay camouflaged on the seabed. It is easily recognized by its golden sandy to light green color, as well as an irregular white ring pattern. Spotted wobbegongs also have 6–10 dermal lobes on each side of the head and nasal barbels that help them sense their environment.
Native to the coastline of Australia, spotted wobbegongs are commonly found on algae-covered rocky reefs, coral reefs, and sandy areas at depths of up to 110 meters (360 ft). These sharks are often seen in shallow waters barely deep enough to cover their bodies.
Spotted wobbegongs are typically inactive during the day, resting motionless, but at night they become more active and stealthily hunt bottom-dwelling prey such as crabs, reef fish, rock lobsters, and octopuses. They are often observed returning to the same resting site after a night of hunting.
While they are slow and relatively small compared to other shark species, spotted wobbegongs can be surprisingly aggressive. There have been four confirmed attacks on humans without provocation, along with another 28 bites from unidentified wobbegong species. Numerous reports also exist of wobbegongs biting humans when stepped on. Once they bite, they are reluctant to release their grip.
Wobbegongs are often caught as both target species and bycatch in commercial and recreational fisheries. From 1990 to 2000, their catches declined by over 60 percent. Their tough, attractively patterned skin is commonly used as decorative leather, and the meat of spotted wobbegongs is considered a delicacy.
6. Pyjama Shark
Pyjama sharks are easily recognizable by their distinct stripes, short but prominent nasal barbels, and dorsal fins located far back on their bodies. This species is relatively small for a shark, hatching at a length of 14–15 centimeters (5.5–5.9 in) and typically reaching maturity at 58–76 centimeters (23–30 in).
As a nocturnal species, pyjama sharks tend to be slow-moving during the day and are often found resting in caves and crevices at depths of up to 100 meters (328 ft). They primarily feed on crustaceans and small fish, such as anchovies.
Because of their small size and feeding habits, pyjama sharks are harmless to humans. Likewise, humans pose no significant threat to them. These sharks are typically discarded when caught as bycatch and are not used for consumption.
Larger shark species are the primary predators of pyjama sharks. However, pyjama sharks are not considered to be at risk of extinction and can often be found in the southeast Atlantic Ocean and the western Indian Ocean. They are particularly common in the Cape Province of South Africa, with older, unconfirmed reports of sightings in the waters of Mauritius and Madagascar.
5. Angular Roughshark
The angular roughshark gets its name from the rough, tooth-like scales called “denticles” that cover its body and two large dorsal fins. This rare shark glides along the seabed, frequently stopping to hover over muddy or sandy surfaces. Preferring to stay close to the seafloor, angular roughsharks typically live at depths ranging from 60 to 660 meters (200-2,170 ft).
Angular roughsharks are thought to use a suction mechanism to feed on mollusks, crustaceans, and polychaete worms. There have also been occasional reports of them feeding on the egg cases of other shark species. These sharks are mainly found in the eastern Atlantic Ocean, along the western coasts of Africa and Europe, as well as in the Mediterranean Sea.
In the past 50 years, the increased use of bottom trawling in the Mediterranean and northeast Atlantic has caused angular roughsharks to become extremely rare in many of their native habitats. In some regions, they are considered critically endangered. Although they are not specifically targeted by fisheries, they are often taken as bycatch and used for oil, human consumption, and as food for fish farms.
4. Goblin Shark
Goblin sharks are rarely seen by humans since they dwell at depths of up to 1,300 meters (4,265 ft) below the surface. However, some individuals have been observed at depths of 40–60 meters (130–200 ft). Most goblin sharks caught have been off the coasts of Japan, although the species is believed to be found worldwide, with larger populations in Japan, New Zealand, Australia, France, Portugal, South Africa, Suriname, and the US.
Goblin sharks are easily recognized by their long, flattened snouts and exceptionally sharp, fang-like teeth. Their snouts are adorned with numerous tiny electro-sensitive receptors that detect electric fields. These sharks have translucent skin, allowing their oxygenated blood to be visible through their capillaries, giving them a unique pinkish-gray to bubblegum pink coloration.
Despite their peculiar appearance, the goblin shark’s most extraordinary feature is its slingshot-like jaws. While a human’s mouth opens at around 50 degrees, these sharks can extend theirs to an impressive 111 degrees. When prey comes within reach, their jaws extend at a speed of 3.1 meters (10.2 ft) per second, bite down, then reopen before snapping shut again.
Scientists are still unsure why goblin sharks reopen their mouths after making a kill, but it is thought that this behavior helps them secure slippery prey, such as squid, more effectively.
Experts predict that goblin sharks may be found in British waters by 2050. With 40 shark species already inhabiting UK waters, the expected rise in water temperatures due to climate change may bring new species, including goblin sharks, from the Mediterranean and African coasts. It’s estimated that another 10 shark species might be found in UK waters in the future.
3. Greenland Shark
The Greenland shark is among the largest shark species on Earth, growing up to 6.5 meters (21 feet) in length and weighing as much as 900 kilograms (2,000 pounds). Despite its massive size, its fins are relatively small. The shark has slender, sharp teeth in its upper jaw, while the lower jaw contains much larger, smoother teeth.
Greenland sharks display a variety of colors, including gray, violet, brown, and black. While Inuit hunters occasionally cook and eat these sharks, their skin is toxic to most animals, including dogs. When dogs consume raw shark meat, they have been known to act in a drunken-like state.
Most Greenland sharks are blind due to parasitic worms that attach to their eyes. Fortunately, these sharks dwell in near-complete darkness beneath the ice of cold waters, making their blindness less of an issue for their survival.
With their exceptional sense of smell, Greenland sharks easily find food. Their preferred meals include the carcasses of narwhals and belugas, as well as seals, sea lions, salmon, halibut, and herring. There are also occasional reports of Greenland sharks engaging in cannibalism.
The lifespan of Greenland sharks is truly remarkable. Their eyes contain transparent, metabolically inactive tissue that accumulates new layers throughout their life. Studies of 28 Greenland sharks captured as bycatch revealed them to be the longest-living vertebrates on Earth.
The oldest known Greenland shark was estimated to have lived for 392 years. However, this estimate could vary by as much as 120 years, placing the shark’s true age anywhere between 272 and 512 years.
Greenland sharks are primarily found along the coasts of countries such as Canada, Norway, Iceland, Ireland, the UK, and Greenland. Researchers are keen to uncover the factors behind the sharks' extraordinary longevity, hoping to gain insights into the life expectancy of other species, including humans. These sharks also seem to resist diseases that typically shorten the lifespans of related species.
Much about these ancient predators remains a mystery, with scientists continuing to study them for clues about their unique biology and survival.
2. Cookiecutter Shark
The cookiecutter shark, though rarely exceeding 50 centimeters (20 inches) in length, is one of Earth’s most daring predators. It has a distinctive cigar shape with a brown top and a glowing light underside that lures in other fish.
Unlike most predators, cookiecutter sharks do not kill their prey. Instead, they use the speed and movement of other fish to their advantage, quickly turning around to take a single, golf-ball-sized bite from their attacker.
This unique feeding method allows cookiecutter sharks to target much larger animals than themselves, such as seals, whales, and other sharks. The distinctive scars left behind by the shark’s specialized teeth, which scoop out a hemispherical plug of flesh, help scientists understand its diet. It appears that nothing is off-limits, with reports even suggesting these sharks leave marks on the sonar domes of nuclear submarines.
Cookiecutter sharks typically dwell at depths of about 1,000 meters (3,280 feet) during the day and ascend at night to hunt. Despite their elusive nature, human activities appear to have little impact on this species. Their distribution is patchy, with sightings reported in locations such as southern Brazil, Cape Verde, Guinea, Angola, South Africa, Mauritius, New Guinea, New Zealand, Japan, Hawaii, Australia, and the Bahamas.
For many years, cookiecutter sharks were thought to be harmless to humans due to their small size and remote habitat. That changed in 2009 when the first documented attack on a human occurred in Hawaii. About 90 minutes after sunset, one shark bit a swimmer’s leg. Prior to this, the only confirmed human bites were found on corpses.
1. Frilled Shark
The frilled shark is considered one of the most primitive shark species still in existence. Its snake-like appearance, featuring a long body and small fins, has led to several reports of "sea serpent" sightings. This shark is named for the six pairs of gills that meet beneath its throat, forming a frilly collar. However, the most distinctive feature of this shark is its jaws, which hold 300 small, three-pronged teeth arranged in 25 rows.
Although typically found at great depths, frilled sharks have also been observed at depths between 50–200 meters (160–660 feet), where they primarily feed on squid and various fish, including other sharks. Their mouth and body shape suggest they are capable of consuming prey that is more than fifty percent of their own body length.
Frilled sharks have a scattered global distribution. They have been recorded in the waters of Scotland, Ireland, Australia, New Zealand, Japan, California, Chile, Namibia, and Norway, with unconfirmed sightings in the Indian Ocean.
Frilled sharks may be at risk due to their long gestation periods and low reproductive output. Even small declines in their population could have serious repercussions, as these sharks are often taken as bycatch through deep-set longlines, gillnets, and trawls. Their meat is used in fish meal, eaten by humans, or discarded. Little is currently known about the global population size of the frilled shark.
