Thought questions about sharks, knowledge about sharks

Sharks generally live in the sea.

Sharks are sensitive to water temperature, and when the water temperature drops below 20, they will lose their vitality. Sharks are generally found in tropical and temperate oceans on Earth, and only a few species of sharks live in cold waters, such as Greenland sharks. Not all sharks live in the sea, there are some species of sharks that live in freshwater, such as the highly aggressive bull shark.

Sharks mostly feed on marine animals such as fish. Sharks feed on injured marine mammals, fish, and carrion, culling weaker members of the animal.

There are sharks in oceans all over the world, but most of them live in tropical waters! They are nocturnal animals and usually hide under rocks to rest during the day!

This thing is a fish, it has no lungs, and it can't live without water, so isn't it looking for death when it's so big and shallow water?

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) that rises vertically upwards is 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.

Sharks have thoughts, but they can't compare to people.

There is only one way to hunt sharks, which is to bite the prey lightly, make it bleed, and then leisurely track the smell of blood, and finally eat the prey that is no longer able to resist. And this hunt can go at least a week without eating.

The whole hunting process of sharks is completely with the minimum effort to obtain the maximum benefit. In other words, the process of shark hunting is a super shortcut. The reason why sharks are the most successful creatures in the ocean is because of this survival strategy that pays the least amount of energy and gets the most reward.

There is a profound truth in this survival strategy of sharks, which is that they never make solving problems their first priority.

Trivia about sharks

In many people's minds, sharks are usually only found in the ocean, but this is not always the case, not all shark species live in the ocean. You can also see them in some freshwater lakes and rivers, for example, bull sharks are also used in tropical rivers, but they are also not afraid of the sea, and the rivers of New Guinea, Australia, South Asia, and other regions are home to sharks.

Sharks have always been known for their sense of smell, but their keen hearing is equally impressive. They can hear sounds up to 230 meters away, and can even muffle the muscles of their prey. The reason is simple, unlike humans and most other vertebral mosaic cavities, sharks and their skeletal relatives do not have skeletons.

Their bones are made of cartilage, like things like your nose and ears, which are less dense and flexible, but they don't usually become fossilized like bones.

What kind of water do sharks generally live in? Ask for answers! Where are sharks mainly found?

Hello dear! Sharks generally live in deep waters, and in the evening of each day is their feeding time, moving towards the shore. Sharks are present in all areas of the marine ecosystem.

Almost all coral reef waters are populated with small demersal sharks. Temperate waters are home to sharks, tiger sharks, cat sharks, tridonous sharks, horn sharks, and occasionally flat sharks. These sharks generally inhabit sandy bottom bends and open waters with coral reefs and abundant algae.

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. 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.