Mention sharks, we will first think of the great white shark, that is, the man-eating shark, the absolute ocean overlord, but in fact, the real shark is the cartilaginous fish plate gill suborder shark total name, a total of 8 orders and 25 families, about 250 to 300 species, of which more than 200 kinds belong to the true shark order, there are about 130 species in China's sea.
Petite cute shark
Many people think sharks are dangerous predators, but there are also petite and cute breeds. Cat shark is one of the common breeds, it is also called dog shark, nine sharks, the head is relatively round, the pupil is like a cat is a thin line, small fish shrimp and mollusks as food, can be kept in the aquarium. But cat sharks are still excellent hunters, wild cat sharks can grow up to three meters long, can float on the surface of the sea to pretend to die, and hunt seabirds that come to eat "dead fish".
What is the smallest shark?
The smallest shark, once thought to be a member of the order Horned Shark, is no more than 30 cm long, and this small shark has a luminous organ in its abdomen that both attracts prey and confuses predators. However, the smallest shark throne has now been occupied by the 14-centimeter-long pocket shark, but at present, only single-digit samples have been found in the world, which seem to be juveniles, and it is uncertain how big they will grow up. Unlike other large-billed sharks, the pocket shark's mouth can be said to be a cherry mouth, and there are two pockets next to the pectoral fin. Scientists don't yet know what these two pockets are for, perhaps kangaroo-like pouches. At first glance, the shark looks like a black sperm whale toy.
A flat shark that resembles a sturgeon
Most sharks swim quickly in the water, because sharks do not have gills, and if they do not swim, they cannot let the water flow into the gills to filter the oxygen in the water, and they will choke themselves to death after a long time, so even if they are asleep, they are constantly swimming. However, some sharks like to lie on the bottom of the water to carry out ambushes, which is the flat shark. It doesn't look like a shark at all, but like a toad with teeth.
Flat shark belongs to the order Flat Shark, Flat Shark Family, Flat Shark genus, a total of 4 species of flat sharks have been found in China. Flat sharks blend perfectly with the environment on the ocean floor, and when other fish, including other sharks of the right size, swim by, they will suddenly open their mouths and inhale them, attacking them in a manner similar to flounder or angus. In fact, the ancient Greeks discovered the flat shark and regarded them as a kind of hunting for the well-being fish, and the flat shark is now an endangered animal. Fortunately, most sharks are not endangered.
Another shark that is also good at underwater ambushes is the carpet shark, but it is not close to the flat shark, belonging to the order Whiskers, and there is a more famous member of this order called the whale shark.
Megalodon sharks like train cars
Almost every extant animal has historically seen giant breeds. About 28 million to 1.5 million years ago, the largest megalodon shark in history appeared in the shark family, also known as megalodon shark, megalodon shark, large tooth shark, it can be more than 20 meters long, weigh 40-70 tons, mouth diameter of more than 2.6 meters, bite force of nearly 40 tons, far more than Tyrannosaurus rex. Megalodon's teeth are the size of an adult's palm, with sharp serrations on the edges. Megalodons, like great white sharks, are taxonomically belonging to the cartilaginous fish order Lepto-eating shark genus of the order leptobras, because sharks are cartilaginous fish, in addition to teeth, bones on the body are difficult to form fossils, so most of the data about them can only be speculated. So we had to compare it with the familiar animal, and the reconstruction of the megalodon became a large white shark.
Megalodons are arguably one of the largest aquatic animals in the world, and only Leviathan whales are likely to fight one. Leviathan whales were shorter than today's sperm whales, but had a more fierce personality, with teeth the shape and size of a large mango. Megalodon sharks are faster, cetaceans are smarter, and there has never been a fixed answer to who is better at fighting between the two. Some scientists believe that megalodon sharks are not extinct, but grow in the deep sea, after all, we know less about the ocean than the starry sky. But no real hammer has been found so far.
Sharks with their own pellet saws or vertical saws
Just now we said, sharks are cartilage, so it is difficult to leave the whole fossil, ancient shark fossils are mostly teeth and some broken bones, so after the teeth of the spiny tooth shark appeared, scientists do not know what it looks like.
The spinodon shark lived between the Permian and Triassic periods, and its teeth resembled a cog, and scientists speculate that it may have eaten mainly mollusks such as squid. However, some scientists have restored the following picture.
Other scientists believe that the so-called strange gums are actually just spines on the dorsal fin or elsewhere. So what the spiny tooth shark looks like, no one knows.
If sharks with circular saws look a bit too sci-fi, there are sharks with saws in reality. Sawsharks are such a presence. Sawsharks are found in vast areas from South Africa to Japan, but they are small in stature and not as fierce as they seem.
Another cartilaginous fish that is closely related to sharks, the ray family, has a real saw killer, the sawfish. The largest can grow to 7.6 meters, the snout accounts for one-third of the body length, and in ancient Europe, the saw of this fish could be modified into the sword of the nobility. It looks like a shark, but its mouth betrays it. While hunting, it will frantically swing its head and cut off the fish in front of it. What if I hang a fish block on the serrations, you ask? Sawfish themselves also have a headache, but it is easy to just hang on to the fish, if their sawtooth is often hung on the fishing net, which is fatal. As a result, they have now become cherished animals.
Tongue seeker. Writer, screenwriter, poet, food critic, currently based in Beijing. He has been writing all kinds of books for a long time, and his works involve poetry, history, science and technology, humorous stories, various reviews and other topics, and he has served as a columnist for many magazines and websites. He has been conducting long-term research on folklore, cuisine and mythology in various places. One of the screenwriters of the web animation "Three Kingdoms of Spit".
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