The life of sharks in the sea

 

shark anatomy

The internal parts of the shark consist of flexible cartilage instead of bones. Sharks have a cartilaginous skeleton, and they have 5 to 7 gill slits on each side of their head. These gills are used for breathing purposes and extracting oxygen from the water.

It also has mouths lined with multiple rows of teeth that change and renew periodically, and their teeth vary in shapes and sizes, some of which are serrated and sharp, and some of them are pointed like spears.

There is a side line on each side of the shark's body, and the function of these lines is to detect the movement of the surrounding water to sense the movement of prey and help in movement around these prey, especially at night when visibility is poor underwater.

These lines are sensing systems that consist of a network of fluid-filled channels under the shark's skin. These channels are affected by pressure changes in the water surrounding the shark and lead to the vibration of the fluid in these channels. This vibration is transmitted to the shark's nerve endings, and then the signal is transmitted to the brain To be able to determine the appropriate direction of movement.

Shark Sizes

The sizes of sharks differ from each other, the largest of them is the whale shark, which can reach a length of 16.7 meters, and is the largest fish on earth in general, and the smallest type is the dwarf lantern shark, which does not exceed 20 cm in length, meaning it is the size of a cuff The hand, and there are other types of medium size, such as the great white shark.

Shark Citizen

The habitats of sharks vary according to their types, and each type adapts to the environment around it. Sharks are considered to be fish that are well adaptable to their surrounding environment, and the different types of sharks are distributed between shallow coastal areas, deep ocean bottoms, and in the open ocean.

Some types of sharks live in temperate tropical seas, some of them live in cold and polar seas, and others live in fresh water. The following are some types of sharks and their environment in which they live:

sleeping sharks

It lives in arctic waters all year round.

big eyed dog sharks

It lives at the bottom of the Red Sea at a depth of about 2,195 meters.

bull sharks

They are often found in fresh water, such as: the waters of Lake Nicaragua, Lake Izabal in Guatemala, the Zambezi River in Africa, the Tigris River in Iraq, and 255 km from the upper Atchafalgia River in Louisiana, and it is known that this type of shark traveled an estimated distance 1,609 km up the Mississippi River to Illinois until dams blocked their way.

Shark diet

Sharks rely on hunting for their food; This is because they are predatory and ferocious creatures that feed on a variety of marine animals, which allows them the freedom to move frequently around the ocean without fear of interruption in food sources.

1Sharks usually feed on fish and marine mammals; Such as dolphins, seals, and some sharks that are smaller in size, and there are types of sharks that prefer turtles, gulls, crustaceans, marine mollusks, and plankton as their diet.

shark behavior

Most sharks need to provide a permanent movement of water around their gills, which provides them with the necessary oxygen, and for this they need to be in a continuous and permanent swimming movement even during sleep periods, as they swim during sleep in the water, but their brains are less active.

However, there are other types of sharks that do not need to constantly swim in the water because their bodies contain small ventilation holes located directly behind their eyes, and these openings push the water through the gills to allow the breathing process to take place.

shark mating

The process of reproduction of sharks is similar to the process of reproduction of mammals, where the adult male and female sharks must meet physically in order for the male to pass his male gametes into the body of the female and fertilize her eggs, and this process differs from the method of reproduction of other fish species, where ordinary fish reproduce by releasing their gametes To meet with eggs and fertilize them.

shark sleep

Most shark species are unable to sleep for long periods, and compensate for it by taking breaks to renew their activity, by sleeping for a very few minutes at a time.

The reason sharks are unable to sleep is because they need to swim constantly in order to be able to breathe, as oxygen-rich water flows through their gills when they move. 

But some types of sharks can sleep thanks to their gills that are able to push oxygen-rich water inside them without the need to swim and move the water through them, and an example is the nurse shark (in English: Nurse shark). 

types of shark

There are many types of shark, numbering about 400 species, and the most famous of them are:

whale shark

It is the largest fish species in the world, reaching a length of about 20 m, and weighing about 34,019 kg. This type of shark is characterized by its gray, blue, or brown skin, which is covered with regular spots of light color, and the whale shark It is abundant in the Pacific, Atlantic, and Indian oceans.

basking shark

It is the second largest species of fish in the world, reaching a length of about 12 m, and a weight of up to 7,000 kg. It was called by this name because it often climbs to the surface of the ocean to bask in the sun. One of its famous behaviors is; Slow swimming forward with filtering water that enters its mouth from prey.

mako shark

It is the fastest type of shark, and is characterized by having short fins. The length of the mako shark may reach approximately 4 m, and it weighs up to 553 kg, and its belly appears in a lighter color than its blue back. This type is abundant in temperate and tropical waters in the Atlantic and Pacific Oceans, Indian, Mediterranean.

thresher shark

It is characterized by having large eyes, small mouths, and a long, whip-like tail to collect and stun prey. There are 3 types of this shark: the common thresher, the big thresher, and the marine thresher shark.

bull shark

It is one of the most attacking shark species on humans. It prefers to be found in warm, shallow, shaded waters, near the shore, and is characterized by having a sharp nose, and a gray back that becomes lighter at the bottom. The length of this type of shark reaches about 3.5 m. While it weighs up to 226 kg.

great white shark

The great white shark is about 6 meters long and weighs approximately 1,814 kilograms. It is one of the fierce and frightening sharks that may bite humans but not devour them, and the strange nature of the white shark is that it examines its prey before devouring it.

blue shark

It is called by this name because of the color of its body, as its back is dark blue, and its sides are light blue, and the lower part of it is white, and the length of the blue shark reaches about 3.6 meters, and it is characterized by having large eyes, a small mouth, a slender body, and tends to live In temperate and tropical oceans.

hammerhead shark

The hammerhead shark is one of the ocean fish that is characterized by having a strangely shaped head, which gives it a wider range of vision. It also lives in tropical and temperate oceans, and the hammerhead shark includes several types: wingtip, hammerhead, scalloped hammer, muscovite, large hammerhead, and head sharks.

Shark's relationship with humans

The widespread misinformation about sharks as a human-eating fish has led to an increase in attempts to eliminate and hunt them, but the fact is that there are only 10 types of sharks that pose a real danger to humans.

As for the rest of the species, they do not pose any danger to humans unless they are threatened. Therefore, sharks must be treated fairly and without aggression, and to avoid provoking them or notifying them of threats to avoid their reaction.