The world of the sea and the ocean

In the following lines I will talk about the oceans and the deep sea
I will refer to the oceans and their area and talk about the depths of the ocean and the harsh conditions of living in them and the types of organisms that live in them and then conclude with the strangest information about living organisms in the depths Oceans 

What are the oceans and what is their area
 

The oceans are the largest and greatest part of the large hydrosphere that encircles the globe, and these waters occupy about 71% of the surface area of the globe, equivalent to 510 million km, and it consists of the total areas of oceans, seas and lakes with an average depth of 3800 m, and the number of oceans that surround the planet is five oceans.

What are the depths of the sea and what are the living conditions in them
 

The deep sea is defined as areas of the ocean that are located at a depth of 200 meters or more, characterized by a somewhat difficult ecosystem, for the following reasons: [1]Temperatures do not exceed 5 degrees Celsius.[2]The pressure is 200 times the atmospheric pressure at sea level [3] The sun's rays do not reach it This makes it imperative that marine animals living in these depths adapt to the lifestyle of one of the most challenging environments in the world. 
In ancient times, it was difficult to discover the depths of the sea and their environmental conditions, due to the lack of possibilities to reach the depths, but European scientists began at the beginning of the century.
XIX in search of life in the depths

Life in the deep sea is unfamiliar, even to most biologists Oceanographers believe that the fauna of the deep sea are the same in variety and number as those of tropical rainforests and coral reefs. In fact, there may be 10 million or more species of animals living in deep water. Many creatures have beautiful but bizarre bodies, which have been shaped by such factors as extreme cold, lack of light, and tons of pressure in the deep ocean.

Deep-sea life species can be     1-divided into three groups:  Microscopic creatures called microorganisms,                                   2 -.   Invertebrates (animals without spines), 

and 3-fish

One of the strangest information about life in the depths of the ocean
 

•Jellyfish is one of the oldestp marine animals, with evidence proving that it existed more than 650 million years ago, before dinosaurs and sharks existed.
An electric sea eel can produce enough electrical energy to light ten light bulbs.
Dolphins are one of the most pet marine animals, and they are known to sleep half of their brains with only one eye closed to keep an eye on potentially life-threatening predators.
The octopus has three hearts, and its blood is blue.
Oysters can change their sex more than once depending on what is better for mating.
The male sea horse is the only animal that gives birth instead of the female.
The heart of the prawns is located in his head.
A sea sponge does not have a head, mouth, eyes, sensors, bones, heart, lungs, or brain, yet it is considered alive. Live 
Sea turtles on all continents, except Antarctica. Stone fish are among the dangerous animals that threaten human life because they contain poison
. There are more than sixty species of carnivorous piranhas.