Draughtsboard Shark Facts

How’s this for irony? The draughtsboard shark is a species of the catshark family, but it can bark like a dog.

Technically, it doesn’t use its voice chords – sharks don’t have any organs to produce sound – to bark, but the sound is a result of its unique ability to puff up like a pufferfish. When threatened, the draughtsboard shark can pump water into its stomach and make itself three times as big to scare away possible predators. It returns back to its regular size by letting the water go out of its mouth. However, if the shark is caught and brought to the surface quickly, they can puff up with air instead of water. When this happens, the air is then expelled out of the body with a barking sound, to the amusement of fishermen.

The species is not the only shark that can expand its body to seem bigger to its predators. The blotchy swellshark and the Australian swellshark share this characteristic and have been confused with the draughtsboard shark by early scientists.

The draughtsboard shark lives in the Western Pacific, around the coasts of New Zealand, China, and Japan. It is considered to be endemic to New Zealand. It prefers to live in warm-temperate waters and is usually found on rocky and sandy bottoms at depths of 18 to 220 meters. By day, the shark likes to stay in crevices and caves of rocky reefs. At night, the shark often swims around reefs and over sandy bottoms to hunt for crabs, worms, octopus, squids, snails, krill, spiny lobster, and bony fishes. The shark has even been seen swimming around with the antennae of a lobster sticking out of its mouth – for hours!

Draughtsboard Shark

The shark measures at the average length of 3.3 feet. Rarely, it has reached lengths of 4.9 feet – it’s maximum recorded size was 7.9 feet, but it is suspected that the 7.9 record was based on another species that resembles the draughtsboard shark. It has a thick body with a broad and flat head with a large mouth. It has dark blotches on its light brown or golden body, which is a coloration that’s common to catsharks. It has two dorsal fins that are placed far back on its body. The first dorsal fin is much larger than the second.

Usually segregated by sex, the draughtsboard shark mates when they are at least 24 inches long. The shark is oviparous – the female lays two cream-colored (or brown-colored) egg cases at a time. The eggs have long, spiral tendrils at the corners to help them to be attached to underwater objects such as macroalgaes and sea fans.

The shark is a common species and is harmless to humans. The IUCN lists the shark as Least Concern, since there is no great threat to the species other than the danger of being caught as bycatch by commercial fisheries. Since the shark can survive for a while outside of the water, many of them are thrown back into the water and keep on living. Their life span is unknown.

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Frilled Shark Facts

It’s a snake… It’s the Lochness Monster… It’s the frilled shark!

The frilled shark is a strange creature that resembles an eel. Its body is very thin and slender, with a large mouth filled with more than 300 trident-shaped teeth arranged in 25 rows. Due to its unique anatomy, some scientists suspect that it has been mistaken for a sea serpent. However, the frilled shark rarely emerges to the surface and prefers to dwell in deep waters – at depths from 160 to 660 feet. Another anatomy difference between the frilled shark and the legendary sea serpent is the size. The frilled shark is only five feet long.

Although the body of the frilled shark is shaped like an eel, it doesn’t swim like one. The shark has an oil- and hydrocarbon-packed liver, which helps the shark to hover in midwater. It is suspected that when the frilled shark sees a prey, it strikes like a eel. Another possible explanation for its unique body shape might be that the shark feeds in caves and crevices – its not known for sure.

Frilled Shark

The frilled shark is named after its six pairs of collar-like gills that have frilly edges. Its first gill goes all the way across its throat.

The prey of the frilled shark includes squid, cuttlefish, and octopus. The frilled shark’s trident-shaped teeth are perfectly suited for these slippery marine creatures. However, since the frilled shark is thought to be slow-moving, it isn’t clear how they’re able to capture fast-moving squid. The theory that they strike quickly like an eel might be an explanation; other possible explanations are that they don’t need to eat often (many captured frilled sharks have empty stomachs) and so they catch only sick prey, or that the gills of the shark can be closed in order to create negative pressure, enabling the shark to suck its prey into its mouth.

The frilled shark can be found all over the world, from places like the Caribbean to Southern Africa, but most specimens have come from Japan. A study of 264 frilled sharks was conducted in Japan and in 2007, a Japanese fisherman found a sick, dying frilled shark swimming near the surface of the water.

In the study of frilled sharks in Japan, scientists gained some more knowledge of how reproduction works in the species. The shark breeds throughout the year due to the lack of seasonal changes in deep waters. The average litter has 6 pups, but not all of them survive to be adults. But the most interesting discovery of the study was the shark’s gestation period – it is estimated to be 42 months, or 3 ½ years!

Due its slow reproduction rates, the frilled shark is considered as near threatened by the IUCN. Small numbers of the shark has been caught by deepwater commercial fisheries as bycatch. Sometimes it is taught and sold for meat or fishmeal, but it is not a large part of the fishing economy. However, commercial fisheries in the frilled shark’s habitat have caused a drop in the numbers of the species.

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Coral Catshark Facts

The beautiful coral catshark looks nothing like the catfish. It is named due to its cat-like, slender shape and the color of its eyes. It also moves in a graceful way, like a cat, as it swims – its movement could be described as curving and twisting. They are sometimes called tiger catsharks or coral cats.

The coral catshark is a specific species of the catshark family. As with all the other catsharks, the coral catshark is a very slender shark. What makes it unique is the coloration of the body – the majority of the body is brownish, but there’s a dark pattern as well as white spots scattered all over. They have two dorsal fins with white tips. Their underbelly is white and their heads are narrow. They grow to 24 inches, sometimes up to 28 inches.

The slender, patterned shark is found in the Indo-Western Pacific areas – including Pakistan, India, Malaysia, Singapore, Indonesia, New Guiena, Thailand, Vietnam, Philippines, Southern China, and Taiwan. They live in shallow, tropical waters – they usually limit their depth to 33 feet.

Coral catsharks are oviparous sharks, so they lay eggs and leave them to hatch by themselves. The eggs are purse-shaped with tendrils that help anchor the eggs to the bottom of the sea. After around four months, the eggs hatch and pups, at around 4 inches in length, swim out. Coral catshark pups are rarely seen by humans, probably because they stay hidden within the reef to keep themselves safe from predators.

Coral Cat Shark

The shark is a very active shark and can be found continually swimming around rocky caves and crevices in the ocean, hunting for food and exploring. However, they are mostly seen hunting at night, so that makes them nocturnal predators. The coral catshark likes to feed on invertebrates such as shrimp, small crabs, and clams, as well as small fish. They can be aggressive, attacking other fish that are larger than themselves.

Harmless to humans, coral catsharks are often caught and put in small aquariums in homes, due to their small size. They can live with many different types of tropical fish in aquariums, making them popular with aquarium hobbyists. Another desirable quality of coral catsharks, other than their beautiful and unique looks, is that they can live for a very long time in an aquarium – for up to 20 years. They can even breed in captivity.

Coral catsharks are also eaten by humans in some parts of the world. They are eaten fresh or dried-salted. Other people like to use them as fishmeal or for oil. Although they are not considered as endangered, their habitat is being threatened by the dynamite fishing habits of some countries such as eastern Indonesia. Generally, they are thought to be unimportant to fisheries and sometimes are caught as bycatch.

Even though they are considered as common and widely used in aquariums, not much else is known about the coral catshark. Their life span in the wild and their social behavior are largely unknown.

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California Hornshark Facts

What’s in a name? Sometimes, the name of a shark tells you a lot about the shark itself. The California Horn Shark is found in the eastern Pacific, from central California to the Gulf of California, and sometimes as south as Ecuador and Peru. It has two “horns” – which is actually its two prominent dorsal fin spines. To put it simply, the shark has two fins on its back and both of the fins have a spine sticking out of them, like a horn on a unicorn.

What else is there to know about the California Horn Shark? They don’t look like your typical shark. Their heads are short, large, and blocky. They have high ridges above their eyes. Sometimes they have small dark spots on their tan or grey body, sometimes not. They can grow up to four feet in length.

It’s uncommon to find a California Horn Shark swimming around in the daylight. They are nocturnal creatures that hide under rocky ledges by day and hunt by night. They like to feed on bony fish, mollusks, sea urchins, crabs, worms, and anemones – small ocean creatures that they can find among rocky reefs, kelp beds, sand flats, and small caves. The shark uses its large fins to feel out the prey in the ocean bottom. Sometimes, this makes them seem sluggish, especially when they use their fins to move themselves over the sea bottom instead of swimming.

California Horn Shark

The California Horn Shark’s mating process goes something like this: the male chases the female until she is ready, and then the male bites the female’s pectoral fin while they mate. It takes around 30 to 40 minutes, and then the female carries the fertilized eggs in her body for a few weeks. When it’s time, the female hides the auger-shaped eggs among the rocky reef and leaves them there. Six to nine months later, the eggs are hatched and young California Horn Sharks emerge, around 15 to 17 cm in length.

Young California Horn Sharks are less shy – they can be found swimming along open sandy bottoms instead of hiding in rocky ledges.

Other than their unique looks, the California Horn Shark is highly valued by scientists because of their ability to live for a long time while in captivity – as long as 12 years. Most sharks usually die much earlier than this because they stop eating. Scientists love this shark because they can study them for longer periods of time, so they have gained a lot more knowledge about sharks in general thanks to this species.

They aren’t very dangerous to humans, but if harassed, they will bite fingers. Their horns can be dangerous as well – they can puncture the skin pretty badly.

There is no real commercial market for the California Horn Shark, except for the aquarium trade, which deems the shark as valuable because of their ability to thrive in captivity. However, the shark is killed often as bycatch – they can get trapped in crab traps or gillnets and trawls.

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Ornate Wobbegong Shark Facts

There are 11 different kinds of carpet sharks – sharks that swim along the bottom of the sea and act as “carpets” on rocky bottoms and coral reefs. The ornate wobbegong is one type of the carpet shark. The scientific name of the shark is Orectolobus ornatus, which loosely translates into stretched lobes. This is a good name, since the ornate wobbegong has stretchy, long lobes all around its snout.

The ornate wobbegong lives in the western Pacific Ocean, around the countries of Indonesia, Papua New Guinea, and Australia. The shark can be found in bays, algal-covered rocky bottoms, and coral reefs. It doesn’t swim very deep in the water – the deepest it has been found is 328 feet deep. The shark usually rests on the bottom of the sea floor during the day and hunts in the night. If the water is clear, you’re more likely to find the ornate wobbegong instead of its doppelganger and close relative, the spotted wobbegong.

The shark has a broad, flat head with nasal barbels on its snout, which makes it look like it’s dragging branches of algae in its mouth. It has a golden-brown body with dark rectangular saddles scattered all over. The shark can grow up to 9.5 feet in length, but most ornate wobbegongs are around 6.6 to 8.2 feet long.

Ornate Wobbegong shark

The ornate wobbegong is ovoviviparous and gives birth to an average litter size of 12 pups per litter. When the young sharks are born, they measure at 7.9 inches. They reach maturity at approximately 5.7 feet.

Considered as an opportunistic predator, the shark will eat any fish or invertebrates that looks good to it. The camouflage coloration on the ornate wobbegong helps it to ambush its prey – it hides in the coral reef until the prey comes near and then attacks with its quick jaws. The nasal barbels also attract curious prey. Unfortunately for the prey, especially larger prey, death can take a long time. Since the ornate wobbegong swallows its prey whole instead of chewing, it will hold large prey in its jaws for days until the prey finally dies.

The spotted shark does have its enemies. Any large fish or marine mammals are possible predators of the shark. Humans occasionally kill the shark as bycatch. The flesh of the shark doesn’t have very much value, but the tough and unique skin is used as leather.

Since the shark has sharp, long teeth in the upper jaw and three in the lower jaw, their bites can be painful to humans. The bites are usually shallow, however. They will attack only when harassed or attacked. However, they have been observed swimming towards divers, so they can be hostile. People should be careful when swimming in tidepools that might be home to ornate wobbegongs, since it can be hard to see these sharks due to their camouflaged bodies. 39 attacks by wobbegong sharks on humans have been reported.

Ornate wobbegongs are listed as Near Threatened by the IUCN, due to habitat degradation, pollution, and unregulated fisheries.

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Greenland Shark Facts

As you can tell from the name, the Greenland shark is found in the cold waters around Greenland, but it also lives in other areas of the North Atlantic, including Iceland. This large shark can grow to over 20 feet (scientists haven’t found their maximum size yet) and prefers very cold and deep water, from 600 to 2,400 feet below the surface. They will occasionally go near the surface, but only if the surface water temperature drops to 33 degrees Fahrenheit or lower.

The Greenland shark’s coloration varies from shark to shark, from brown to black to purplish or slate gray. The dorsal fins are both small (no reason to have an upright fin slicing through the surface of the water if the shark always stays deep underwater) and are similar in size. The huge shark has very small eyes, but they often look like they are glowing due to a parasite that’s often found on the Greenland shark. The parasite is a copepod (a very small crustacean) that lives on the eyes and eats the corneal tissue, which does cause some eye damage, but also gives the shark’s eyes an ethereal glow. This glow attracts the shark’s prey, which is very helpful for the sluggish shark. When the prey gets close, the Greenland shark simply inhales and sucks in the prey. Also, the shark has a very keen sense of smell and it lives deep in dark water, so the eye damage isn’t a big deal.

Even though it has glowing eyes, the Greenland shark is often found sleeping in the water and is considered to be an inactive shark. It is also known as the sleeper shark. Although it has a reputation for being lazy and slow and sleepy, some scientists think that the Greenland shark is able to swim really fast at short bursts, due to the short and broad size of its tail.

greenland shark

The shark generally eats fish, such as capelin, char, halibut, herring, lumpfish, and salmon, as its main diet. It also feeds on larger marine mammals, including seals, sea lions, and cetaceans. However, the Greenland shark isn’t a picky eater. If something looks good, it will chomp down on it. For example, a Greenland shark stomach was found to have an entire reindeer body in it, including its antlers! They do eat other animals such as horses and polar bears. The shark’s teeth are pretty small compared to its huge body, but the teeth are razor sharp.

The shark is ovoviviparous and give birth to litters of up to 10 pups. Young Greenland sharks are born at 15 inches.

Despite its large size, Greenland sharks are sometimes caught as bycatch by fishermen who are fishing for halibut and other deep-water species. They used to be targeted for their liver oil by fisherman from Norway, Iceland, and Greenland, but not anymore. Their flesh is somewhat unsuitable for human consumption – it has to be boiled or dried beforehand because it is poisonous when fresh. It’s also poisonous to other animals – Inuit hunters avoid feeding the flesh to their dogs.

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Epaulette Shark Facts

The epaulette shark has a cream or brown body with many small brown spots that are widely spaced across its body, with two large black spots with white outlines located just above the pectoral fins. These beautiful and unique spots remind some people of the epaulettes, or circles of fringes that are on the shoulders, on a soldier uniform. You could call the epaulette shark the soldiers of the sea!

A small shark, the epaulette shark grows up to only 42.1 inches. They are born at 5.9 inches and reach sexual maturity at 23.6 inches for males and 25.2 inches for females. When they mate, the male bites the female’s body and gills. The female will then release around 50 eggs, each egg case measuring around 3.9 inches. The egg cases don’t hatch until after around 120 days. Young epaulette shark grow in size very slowly – they grow only 1.2 inches in the first year.

Native to the western Pacific Ocean, the epaulette shark can be found in the ocean water around New Guinea and northern Australia. The shark usually sticks to shallow water coral reef habitats, at depths from 0 to 164 feet. It swims near the sea bottom and is even able to “walk” by using its muscular pectoral fins to push itself through the water. The pectoral fins are broad and round – and they are attached to the body in a unique way that allows them to have an increased range of motion (so they can “walk”) as compared to other sharks’ pectoral fins. Their slender bodies also help them be able to swim through narrow reef crevices.

epaulette shark

An interesting fact about the epaulette shark is that it can actually turn off its non-essential bodily functions for several hours in order to survive in low-oxygen areas in the water. This is helpful when they get caught in tide pools. Scientists are conducting research on this shark in order to find out how it works so they can use that knowledge to help stroke patients or patients undergoing heart surgeries.

At dusk and at dawn, the epaulette shark hunts for its prey with electroreception and a strong sense of smell. It likes to feed on crustaceans and segmented worms; young epaulette sharks usually eat polychaete worms. With its short snout, the epaulette shark can burrow through the sand to find its prey. The shark has small but sharp teeth – they are broad on the bottom and very narrowly triangular on the top. The teeth can be flattened to form crushing plates! Their unique teeth help them be able to crush through hard-shelled prey. However, it takes them a while to chew food before swallowing.

Since the shark is pretty small, it has a lot of predators including larger fish and other sharks. However, the two big black spots on their back can fool predators into thinking that the spots are the huge eyes of a bigger fish.

Humans aren’t predators that the epaulette shark has to worry about, since commercial fisheries aren’t interested in the shark. However, people at beaches can easily catch the shark because it’s not fast moving (remember the large pectoral fins). It might “run” away from you on its fins. It is harmless to people, but it might give a small bite if touched or handled in any way.

The docile, spotted little shark is listed as Least Concern by the IUCN.

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Galapagos Shark Facts

In 1905, a gray shark with a ridge between its two dorsal fins was swimming around the Galapagos Islands when it was discovered and named the Galapagos shark. It is also known as the grey reef whaler and mackerel shark.

The average size of the aggressive shark is 10 feet long, but they can grow up to 12 feet long. The body is slender and its first dorsal fin is tall and almost straight, poking out of the water menacingly. It strongly resembles two other sharks – the grey reef shark and the dusky shark, so some confusion in data have been reported due to the resemblance. One good way to tell the difference between the Galapagos shark and the dusty shark, other than the difference in their dorsal fins (it is taller in the Galapagos shark), is to count the number of precaudal vertebrae. There is 103 to 109 in the Galapagos shark and only 86 to 97 in the dusky shark. However, you can’t exactly do this while you’re underwater observing them – so it’s really hard to tell the difference if you see one of these sharks swimming in the water.

Galapagos Shark

They prey on squid, eels, octopus, flatheads, groupers, flatfish, triggerfish, and other fish that dwell on the ocean floor. They also eat young pups of their own species, so pups usually stay in shallow waters to keep themselves safe and alive. Their upper teeth are serrated and broadly triangular. The lower teeth is finely serrated. However, the shark isn’t limited to fish and invertebrates – they often feed on sea lions and marine iguanas that live on islands.

The Galapagos shark usually travels in schools. They live in open, warm oceans at depths of 16 to 200 feet. They can be found in tropical seas near islands. The shark prefers clear, tropical waters with strong currents. They like to swim above coral or rocky bottoms. Their distribution around the world is very patchy – they can be found in diverse areas from the Virgin Islands to Hawaii to Walter;s Shoal, south of Madagascar.

The shark can live up to 24 years. They don’t reach reproduction age until they’ve lived for 10 years. Their mating ritual is apparently very rough, since female sharks often have scars around their gills, fins, and body from biting by the males during mating. Galapagos sharks are viviparous, which means that they give birth to live pups. Their average litter size is 4 to 16 pups, each measuring to 24-31 inches in length.

Since the Galapagos shark is not widely distributed around the oceans of the world, they are not targeted by commercial fisheries. However, their flesh is tasty for humans to eat. Our flesh is apparently tasty to them as well – there have been reports of attacks on humans by the shark, one fatal (in the Virgin Islands). They are often attracted to divers and aren’t frightened by aggressive actions by the divers. Instead, they become more excited and are more likely to attack. When attacking, they arch their back, raise their head, and lower the caudal and pectoral fins. While doing all these maneuvers, they swim in a twisted, rolling motion. That’s not a sight that any diver or swimmer likes to see.

Right now, the Galapagos shark is listed as Near Threatened by the IUCN.

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Dusky Shark Facts

The scientific name of the dusty shark is Carcharhinus obscurus. Carcharhinus is
derived from two Greek words: “karcharos” and “rhinos.” Respectively, they mean “sharpen” and “nose.” Obscurus is latin for “dark, indistinct.”

This scientific name makes sense, since the dusty shark does indeed have a sharp, pointed nose and its body color is dark. The coloration of the shark is bluish gray on the top of the body and white on the bottom. Often, a stripe along its body, from the pelvic fins to the head, can be found on the dusty shark. They can grow up to 12.5 feet, although the average length is 10 feet. They usually weight at around 350-395 pounds. Females are slightly larger than the males. They can live for around 35 years.

Found in many areas all over the world, the dusky shark lives along continental coastlines in tropical and temperate waters. It can be found in various places, including the California coast, the eastern coast of the US, along the eastern coast of South America, and around the waters of the south part of Africa. It’s also found all around Australia and parts of the Mediterranean and the Western Pacific. Dusty sharks that are located in the western Atlantic and eastern Pacific migrate north during the summer months. They move back south in the winter.

dusky-shark

Usually a bottom feeder, the shark swims at different depths in the water, from 1,240 feet deep to near the surface. They like to hunt many different types of bony and cartilaginous fishes and invertebrates, including herring, eels, groupers, octopuses, mullet, croakers, starfish, rays, other sharks, mackerel, tuna, bluefish, flatfish, squid, and even sometimes garbage in the water thrown away by humans.

The reproduction of the dusty shark occurs only every other year. The sexes of the shark are mostly segregated, even traveling in separate groups when migrating. When it’s time to give birth, female dusty sharks in the western North Atlantic drop off their pups in shallow bays and estuaries, so the young sharks are protected from predators such as the bull shark. The average litter size is 6 to 14 pups.

The dusky shark is labeled as Near Threatened by the IUCN. The species is harvested in the western Atlantic for its fins. The fins are used for shark-fin soup base. Humans also eat its flesh. Other parts of the body are also valued by humans – its skin is used for leather and its liver oil has important vitamins. However, in recent years, catch rates of the shark has been reduced to recreational catches and as bycatch in the swordfish and tuna fishery. Another factor contributing to their dwindling numbers is their slow growth rates. The dusty shark’s population numbers in the northwestern Atlantic and the Gulf of Mexico has reduced by 15 to 20% since the 1970s.

There have only been a few attacks by the dusky shark on humans, but they are considered as dangerous because of their large size and their proximity to the coast. They can also become aggressive if they are provoked.

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Horn Shark Facts

When you think of a shark, you certainly wouldn’t picture a shark like the horn shark. With their spotted skin, pig-like snout, and oddly-shaped head with two ridges where their eyes are, horn sharks are small at three feet long and slow, clumsy swimmers. They have two high dorsal fins with stout spines. They laze around in caves, crevices, or algal beds during the day. But they are fierce predators just like any other shark, hunting during the night.

Horn sharks use their powerful jaws and molar-like teeth to crush the shells of mollusks, echinoderms such as sea urchins, and crustaceans. The powerful mouth of the horn shark has the highest known bite force relative to its size of any shark. Now that’s a predator. Some horn sharks’ teeth and fin spines are stained purple from feeding so much on sea urchins. They also hunt invertebrates and small bony fishes. Young horn sharks like to feed on polychaete worms and sea anemones. Using suction and levering motions with its body, horn sharks often have to pull their prey from the sand. They find their prey with their sense of smell and electroreception.

Horn sharks live in a specific area only – the coastal waters along California to the Gulf of California. Young horn sharks and adult horn sharks are segregated – the youngsters swim around deeper sandy flats while the adults prefer shallower rocky reefs or algal beds.

horn-shark

The mating habits of horn sharks are another unique thing about them. First, the male chases the female to show interest and then both sharks go to the bottom of the sea. The male then grips the female’s pectoral fin in his teeth and they mate for 30 to 40 minutes. Afterward, the male leaves and the female puts her snout in the sand and spins around for 30 minutes. The mating season is during December and January, and then the eggs are laid from February to April. Their reproduction is oviparous, which means the female horn shark lays eggs. But they don’t merely lay eggs and swim away – after laying up to 24 eggs, the female picks the eggs up and hides them in crevices to protect them from predators such as large marine snails that like to drill into their egg shells to extract the yolk. The eggs themselves are unique as well; they are shaped like augers.

There aren’t very many predators of the horn shark, but they do have a few. They are eaten by larger fishes and the northern elephant seal, as well as bald eagles. Other would-be predators, like Pacific angel sharks, have been witnessed spitting out horn sharks because of the spines sticking them in the mouth. Humans are another predator, although not a frequent one. Horn sharks are sometime caught as by-catch by commercial fisheries. In Mexico, the horn shark is eaten as food and used as fish meal. In California, the spines of the shark are made into jewelry. The horn shark population isn’t considered as threatened and the International Union for Conservation of Nature doesn’t have enough information to determine their conservation status.

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