Sharks don't have fingers that they can use to feel and touch. Instead, like other fish, a shark has a lateral line running along the middle of its body from head to tail.
Sharks do not have bones.
They are a special type of fish known as "elasmobranchs", which translates into fish made of cartilaginous tissues—the clear gristly stuff that your ears and nose tip are made of.
So why don't sharks have fingers? Although the genetic program needed to create digits might exist in sharks and many other kinds of fish, they only activate it briefly, said University of Florida graduate students Renata Freitas and Guangjun Zhang.
Most sharks have eight fins: a pair of pectoral fins, a pair of pelvic fins, two dorsal fins, an anal fin, and a caudal fin. Pectoral fins are stiff, which enables downward movement, lift, and guidance.
When the mouth is open and attached to prey, the labial cartilages and the cheeks they support keep the mouthful of ripped flesh inside the shark's mouth. Figure 4. Daliatias, the extant kitefin shark, has relatively large labial cartilages (not colored) and thick lips.
Sharks do sometimes look as if they're smiling. They're often portrayed in books and movies as smiling. But scientists say it's not likely sharks can or do smile.
Is it OK to touch a shark? While it may be tempting, Julie Andersen of Shark Angels says that divers should resist the urge to touch sharks. Julie Andersen — one of Scuba Diving's 2012 Sea Heroes — is founder and executive director of Shark Angels, a U.S. nonproft dedicated to protection of sharks.
So, do sharks feel pain? Yes – but it is different to how we express pain . Sharks do not have the same nervous system as mammals but what we do have in common are neurons called nociceptors. These receptors are designed to detect potential harm – such as temperature and pressure.
Yes, sharks have a tongue, and it is referred to as a “basihyal” rather than a tongue. A shark's tongue cannot move in the same way that a human tongue can since it is not a muscle. The bottom of a shark's mouth contains this little thick chunk of cartilage, and it doesn't have any taste buds or perform any functions.
Some sharks such as the nurse shark have spiracles that force water across their gills allowing for stationary rest. Sharks do not sleep like humans do, but instead have active and restful periods.
Sharks have bilateral symmetry, and some of their organs come in pairs: in normal development, they'll have two claspers or two uteri, and a pair of ovaries or testes.
Sharks have better sight than what humans have in clear water. Sharks are not blind, and their vision is far better than we can imagine. While sharks have trouble distinguishing colors, their vision is still good enough to accomplish death-defying feats when hunting their prey.
For example, sharks have two penises, sort of. Known as claspers, these two reproductive organs are only on male sharks and they act as the channel for the semen to enter the female's cloaca during mating. The clasper essentially latches on to the female to facilitate reproduction.
The most bony things are, in fact, the teeth. They're made of dentine and enamel-like tissue, just like our teeth, but the rest of the skeleton is just soft cartilage coated with this hard calcium phosphate layer.
Although sharks are not composed of bone, these fish can fossilize. Dried shark jaws often look as if they are made of bone, but they are not, says the NOAA. As sharks get older, calcium salts are deposited into their skeletal cartilage to strengthen it. These minerals allow most sharks to fossilize nicely.
While there is no external ear visible on sharks, they have inner ears that allow them to hear sounds from up to 800 feet away.
Sharks can't make any noise, so they use body language to communicate.
Sharks have six highly refined senses: smell, hearing, touch, taste, sight, and electromagnetism. These finely honed senses, along with a sleek, torpedo-shaped body, make most sharks highly skilled hunters. They often serve as top predators - keeping populations of prey species in check.
Their ability to sense these movements may lead people to believe that they can sense fear but ultimately the movements help them locate their prey while they're hunting. Sharks can sense the earth's geomagnetic field, but they can't sense fear.
It is a comforting move more associated with pet dogs than fish. But this leopard shark proved that it's not just pups that enjoy a belly rub from time to time.
The wild wriggling and squirming fish do when they're hooked and pulled from the water during catch-and-release fishing isn't just an automatic response—it's a conscious reaction to the pain they feel when a hook pierces their lips, jaws, or body.
The leopard shark is the first on our list of least dangerous shark species to be utterly harmless to humans. There has not been a single report of a human being bitten by a leopard shark. They live primarily in shallow waters, are rarely found more than twenty feet below the surface, and feed on crabs and small fish.
There have been cases where punching a shark has caused it to cease attacking someone, but often the person being attacked has still sustained terrible injuries as a result of the initial attack.