Category: Fish

Sharks don’t have lungs, but they do have to breathe oxygen to survive. Instead of breathing air, though, sharks get oxygen from the water that surrounds them. The concentration of oxygen in water is much lower than in air, so animals like sharks have developed ways to harvest as much oxygen as they can. Is […]

Female sharks can reproduce without having sex, scientists have found. A female hammerhead shark has given birth without mating with a male and its offspring has no paternal DNA. This is the first scientific report of asexual reproduction in sharks. Female sharks can reproduce without having sex, scientists have found. How does the great white […]

The only ways to confirm white shark pregnancy is by detecting pregnancy hormones indicators in their blood stream or identifying embryos or eggs via an ultrasound – both are very difficult processes to do with plump white sharks! How long does a shark stay pregnant? 104 Weeks Along. Some shark species carry their young in […]

Many of the scars are inflicted by other white shark either during mating or as a result of “competitive biting.” White sharks are also susceptible to injuries from prey items such as bites and clawing from sea lions and seals. Why are sharks scratched up? If you’re a fish with an itch, a shark would […]

Shark species that lay eggs include: Bamboo sharks. Wobbegong sharks. Carpet sharks. Horn (bullhead) sharks. Swell sharks. Many catsharks. Do some shark species lay eggs? There are over 500 species of shark living in waters around the world and the majority give birth to live young. The remainder are oviparous, meaning they lay eggs. Around […]

But look out! A whole bunch of sharks give birth to live baby sharks, called pups. Mako sharks, bull sharks, lemon sharks, and blue sharks are a few examples of sharks that are born live. Great white sharks usually have only one or two pups at a time, but some of the other sharks can […]

The general rule of thumb is that sharks can cruise at about 5 mph (8 kph)—roughly the same speed as the fastest Olympic swimmer. If you’re just a good swimmer, they have you beat. But often they are swimming around at a slower speed of about 1.5 mph (2.4 kph). These fish are predators. Why […]

No so with sharks. They have a neat trick called “gastric eversion” up their proverbial sleeve. Basically, if a shark wants or needs to eject its belly contents, it just FLIPS its stomach out of its mouth, and everything goes flying — a little like dumping out your pockets to empty them. How do sharks […]

A shark’s powerful stomach acid can dissolve smaller bones like those in a fish. Others, like the bones of a mammal, may be regurgitated or digested, depending on the size. Do sharks throw up bones? Bones, feathers, turtle shells, anything that a shark should not have consumed must also be ejected this way. Sharks also […]

Sharks have cartilaginous skeletons. The skeletons are made up completely of connective tissue and muscle. The skeletons of sharks are made of cartilage, just like the rest of its body. Some of the cartilage in a shark’s body is firmer and stronger than the rest – almost resembling bone. How do sharks have no bones? […]

In order to compensate for the loss of lift caused by having a bulkier body and relatively smaller fins, the larger shark has a liver size more than twice that of the smaller. The liver contains light-weight oils and hydrocarbons, which gives the larger shark the increased buoyancy it needs. Do sharks have large livers? […]

“On rare occasions, during mating season among sharks, ‘mating scars’ appear on female sharks’ bodies caused by the males holding onto them,” Najafov wrote. “These scars are mostly deeper cuts and punctures, indicating a more forceful motivation such as coercive mating from the male’s side.” Why do sharks get scars from mating? During this act, […]

Sharks have U-shaped stomachs that use very strong acids and enzymes to dissolve most of what is eaten. The stomach produces an easily absorbed, soupy mush. Only this liquid mush enters the intestines because the pyloric valve (the valve between the stomach and the intestines) is small. How many stomach Do sharks have? An animal […]

Sharks are cartilaginous fish. This means they have a skeleton made of cartilage, a lighter and more flexible substance than bone. What is shark skin made of? Unlike most other fish in the ocean, shark skin is made of dermal denticles, or “skin teeth.” Despite their slick appearance, you can see under a microscope that […]

Sharks don’t have lungs, but they do have to breathe oxygen to survive. Instead of breathing air, though, sharks get oxygen from the water that surrounds them. How do the sharks breathe? As sharks swim water passes through their mouth and is pushed through their gills. The gills filter the oxygen out of the water. […]

Denticles vary in shape according to the species and where they are on the body. Some are so big that the shark uses them as defensive spines or shields! What is the thing on top of a shark called? The dorsal (top) side of a shark is a lighter color than the ventral (bottom) side. […]

about 50 miles. They prefer waters with sea surface temperatures of 50 to 72 degrees Fahrenheit. White sharks have been known to swim as deep as 6,150 feet. How far do sharks travel in a day? I’ve heard estimates of up to about 50 miles in a day, but we don’t know what distance white […]

the Greenland shark. Movement. As an ectotherm living in a just-above-freezing environment, the Greenland shark has the lowest swim speed and tail-beat frequency for its size across all fish species, which most likely correlates with its very slow metabolism and extreme longevity. Do sharks move slow? The general rule of thumb is that sharks can […]

Sharks are built for bursts of speed as they attack their prey, much like lions and tigers on land. They need to be able to swim fast enough to pursue their prey for short distances, then make the lunge for the kill. The speed of a shark also depends on the species. Why do sharks […]

The general rule of thumb is that sharks can cruise at about 5 mph (8 kph)—roughly the same speed as the fastest Olympic swimmer. If you’re just a good swimmer, they have you beat. But often they are swimming around at a slower speed of about 1.5 mph (2.4 kph). These fish are predators. Why […]