How much do you know about the basics of sharks?

Whale sharks are the largest fish in the sea and can reach up to 60 feet in length when they reach adulthood. Despite its large size, the whale shark has the smallest teeth among sharks. The smallest shark is the dwarf horn shark, small enough to fit in your hand.

It's about 6 to 8 inches long and weighs less than a pound. Sharks must not stop swimming to allow water to pass through the gills or they will suffocate. Sharks differ from bony fish in that they do not have a swim bladder to control snorkeling.

If you stop swimming, most of the sharks will sink down. To reduce weight in the water, the liver of the shark has a large amount of oil.

Sharks are very heavy, very ferocious, need to eat a lot of food in one meal, and are carnivores, and this animal is very predatory.

The shark body is long spindle-shaped. gill cleft lateral, pectoral fin normal, not healed with the anterior edge of the snout; dorsal position of northern fin; Crooked tail type.

1. Appearance characteristics:

Sharks have hard, muscular bodies that are spindle-shaped to varying degrees. The muzzle and nose parts vary from species to species, with pointy ones, such as the gray mako shark and the great white shark; There are also large and round ones, such as the tiger shark and the wide tiger shark with a flattened head. The tail (caudal fin) is vertically upward, roughly crescent-shaped, and the upper part of the caudal fin is much larger than the lower part in most species; It is especially sensitive to odors in seawater, especially to the smell of blood.

2. Habits:

Sharks mostly feed on marine animals such as fish. Sharks feed on injured marine mammals, fish, and carrion, culling weaker members of the animal. Sharks also eat litter and other waste left behind by boats.

In addition, some sharks also hunt a variety of marine mammals, fish, and animals such as turtles and crabs. Some sharks can go months without feeding, and the great white shark is one of them. It is reported that the great white shark is going to be separated.

Eat only once in a month or two.

Here's what you know about sharks:

1. The shark's body is hard, muscular, and in varying degrees it is a spindle and a swift shape. The muzzle and nose parts vary from species to species, with pointy ones, such as the gray mako shark and the great white shark; There are also large and round ones, such as the tiger shark and the wide tiger shark, which have a flattened head. The tail (caudal fin) is vertically upward, roughly crescent-shaped, and the upper part of the caudal fin is much larger than the lower part in most species;

2. The shark's body is streamlined to reduce the resistance of movement in the water. The trunk has dorsal fins, anal and caudal fins, and a pair of pectoral and pelvic fins. The caudal fin is large at the top and small at the bottom, which is caused by the caudal vertebrae deflecting to the upper lobe. The cloaca foramen is located between the two ventral fins.

3. All sharks have a body of cartilage. The skeleton of a shark is made of cartilage, not bone. Cartilage is lighter and more elastic than bone. All sharks belong to the class Sharks, and all sharks have cartilage.

4. Shark** has a large number of mucus glands, secreting mucus to make the body surface sticky and slippery, which can not only reduce the resistance of swimming in Changyuan, but also prevent the body from the invasion of germs and parasites.

5. The difference between sharks and bony fish is that they don't have a swim bladder to control snorkeling. If you stop swimming, most of the sharks will sink. In order to increase buoyancy in the water, the shark's liver has a large amount of oil.

6. The surface of the shark is attached with shield scales, which are composed of spinous processes protruding from the body surface and a substrate buried in the dermis. Inside, there are blood vessels and nerve access, similar to those of teeth. The spinous processes of shield scales can be used to reduce turbulence on the body surface when swimming.

7. The most acute organ of sharks is the sense of smell, they can smell very fine substances such as blood from miles away, and track them out.

Shark Introduction

Sharks belong to the subclass Plategill of the Vertebrate phylum Chondritalia, marine life, a few species enter freshwater, and are a group of medium to large marine fish that swim fast. The endoskeleton of the shark is completely composed of cartilage, often calcified, but without any true bone tissue, the pure Kai exoskeleton is not very developed or degenerate, the body is often covered with skin teeth (qualitative scales), the teeth are diverse, with hard muscle, but the membranous bone never exists, and the brain is seamless.

Summary. Hello, the basic knowledge of sharks is that sharks belong to the subclass of vertebrates and cartilage plates, marine life, a few species enter freshwater, and are a group of medium and large marine fish that swim fast. The endoskeleton of the shark is composed entirely of cartilage, often calcified, but without any true bone tissue, the exoskeleton is not very developed or degenerated, the body is often covered with odontic scales, the teeth are diverse, and there is hard muscle, but the membranous bone never has a seamless cranium.

The upper forehead is composed of palatal cartilage, and the lower forehead is composed of Mei's cartilage. Do you have any questions that I would like to answer for you?

Hello, I've seen La Chunming on your question, and I'm manually replying to the content for you, I need a round of time to tell you, please be patient for a while, thank you.

Hello, the basic knowledge of sharks is that sharks belong to the subclass of vertebrates and phylum chondritalia plate-gills, marine, a few species enter freshwater, and are a group of medium and large marine fish that swim fast. The endoskeleton of the shark is composed entirely of cartilage, often calcified, but without any true bone tissue, the exoskeleton is not very developed or degenerate, the body is often covered with skin and dentate scales, the teeth are diverse, and there is hard muscle, but the membranous bone never has a seamless cranial deficit. The upper forehead is composed of palatal cartilage, and the lower forehead is composed of cartilage of Mei's cartilage.

Do you have any questions that I would like to answer for you?

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Popular science knowledge of sharks: Sharks, who live in the ocean, are fish in the ocean.

Before the advent of dinosaurs, sharks lived on Earth for 300 million years, and they remained unchanged for more than 500 million years. The shark, known in ancient times as squid, squid, and sand fish, is a huge thing in the ocean, so it is called the "wolf of the sea".

Traditionally, shark cartilage (shark fin) is high in protein, but this is wrong. Eggs contain more protein than shark fins. In addition, studies have shown that sharks are prone to accumulating mercury, and shark fins contain a certain amount of neurotoxins, so they are potentially harmful to humans.

Sharks are in danger of extinction due to decades of mass hunting.

The body is generally spindle-shaped and divided into three parts: head, torso, and tail. The body surface has small shield scales, lateral lines on the side of the body, and the body length is about 1-20 meters. The bones of the whole body are cartilage, the skull and vertebrae are calcified, so there is a certain hardness, and the skull has no bone seams.

The cephalad is flattened, slightly thicker near the pectoral fins, tapering posteriorly, the abdomen is flattened, the mouth is on the ventral surface of the head, transversely lobed, and the maxillary and inferior anterior jaws have well-developed sharp teeth.

1. Shark is the common name of more than 300 species of sand species wood fish, their body length ranges from 15 centimeters to 15 meters, but the vast majority of species are less than meters in length and belong to small and medium-sized fish.

2. Sharks have been living on Earth for more than 400 million years, and they are even older than dinosaurs.

3. Sharks don't have a single real bone in their bodies, and if they are put on land, they may be crushed by the weight of their own bodies.

4. In addition to their keen sense of smell, sharks can also hunt by sensing the faint electric field around them, so if a signal from a nearby underwater camera comes out, it may be perceived as food by the shark.

5. Most sharks don't need to eat regularly, and they can withstand hunger for up to two months after a full meal.

6. Shark teeth will be constantly renewed and replaced throughout their lives, and the replacement teeth will move forward like a conveyor belt in the palatal groove to replace them, and the frequency of tooth replacement varies from ten days to several months, and more than 30,000 teeth can be replaced in a lifetime.

7. Some sharks need to swim constantly to keep breathing. This is because they need to swim to get the water into their mouths to get the oxygen dissolved in them, which is one of the reasons why some sharks often open their mouths. Also, sharks do not have swim bladders.

Unable to stop swimming with buoyancy controlled by the swim bladder, it may sink to the bottom of the sea. They can even swim while sleeping.

8. Sharks are one of the few fish whose reproductive mode is internal fertilization.

9. Baby sharks may eat their siblings in their mother's belly.

Ten, not all sharks are ferocious. In general, benthic and greenivorous sharks are relatively slow to move and have a docile personality.

Ten. 1. Large sharks in nature are almost always at the top of the marine food chain, and their natural enemies are only killer whales and sperm whales.

and a few other animals.

Ten. 2. On Earth, on average, no one is killed by sharks, and 5 million sharks are killed by humans. In fact, the probability of a human being killed by a shark is very small, not even as high as being stung by a bee.

Sharks are marine animals. It is one of the largest animals in the ocean and comes in many types. Usually like to hunt shrimp in the sea. It will be sensitive to the smell of blood.

Whale sharks are the largest fish in the ocean; Great white sharks are the smartest predators or travelers; Great white sharks, tiger sharks, and mako sharks need to swim constantly to be able to breathe.

Sharks have eight dorsal fins.

Sharks have cartilaginous skeletons and are more flexible.

Sharks excrete urine with **.

Sharks never sleep, only quiet periods of rest.

Sharks do not become infected.

The shark is known as a "sea hunter", but that's not what it really is. Sharks will not attack unless they are in a "bloody rage", or if they find injured food and are extremely hungry.

Sharks are a large ectotherm (cold-blooded) on the bottom of the sea, and there are more than 300 species of them.

One of the characteristics of sharks is that their teeth do not stop growing due to age, and when their old teeth fall out and are destroyed, new ones will grow in their place.

Sharks possess many strange organs.

Sharks' eyes are unique in that they have many small mirrored plates behind the retina, which allow them to distinguish things even in dim water.

In general, sharks want to know what is far away and will use special organs. The shark's ear is a very important receiver, if there is an injured or ** shark struggling frantically, it will emit a kind of sound wave that cannot be heard by the human ear, that is, infrasound, the shark can hear this sound wave and quickly reach the "destination".

This is the amazing sea hunter - the shark!