القناة الهضمية في الأسماك .. كتاب في سبيل موسوعة علمية .. الدكتور أحمد ذكي

Alimentary canal in fish

It is a channel whose plan is similar to the plan of man on the surface of the earth, except for what necessitated it being simplified, shortened and shortened because there is no need for it. The need of fish is not the need of man.

- the mouth

We start with the mouth. In terms of size, in terms of the opening, whether it is up or down, in terms of strength and weakness, and in terms of the teeth it has, it varies according to the fish, what it is, and what type of food it has.

Sea fish are like land animals, some of them are vegetarian and some are predatory, eating flesh and blood. In the water of the sea surfaces there are innumerable numbers of small organisms suspended or floating in the water, from plants (made by the sun), and from animals, all of which are known as plankton, plankton, or plankton. Small fish live on them, so that larger fish eat them, so that these larger fish eat them. A sea battle is like a land battle, harsh or even harsher.

According to all this, the fish's mouth varies, and varies
His teeth, size, number, and positions.

If there is a need for an example, it is the carp
Vegetarian, his jaws have no teeth. Plankton fish of the herring type have small, needle-like teeth in their jaws. As for sharks, we know as much about their ferocity as their jaws have strong, sharp teeth that sometimes have edges like the edges of saws.

And let's not forget the tongue. In the mouth there is a tongue that has almost no movement, and teeth emerge from the tongue.

-And the throat

It is like the mouth and like the tongue, on which teeth grow. They are all to catch the victim before he swallows it. The victim fish swallows and does not chew. Fish do not have saliva or glands to secrete it.

- in stomach

If the victim reaches the stomach, the digestive juices dissolve it
It also melted its bones and its accessories.

- In the intestines

From the stomach to the meaning, fish is a carnivore, so it is like the carnivore of the earth, with a small intestine. The small intestine absorbs digested food faster. As for eating grass, it is more beneficial, because its absorption is slower.

However, in many fish, many sinuses open together, which are tubes with the other end closed, so they are one-eyed. This is to give food absorption a greater opportunity. It is known as the cecum (Caeca), and the word “one-eyed” is “Caecum”, which is taken from the name “one-eyed” in the thick meaning of the human being, where the appendix is ​​located.
Some fish do not have one-eyed fish, and some have mature one-eyed fish
200.
Waste comes out of the anus, i.e. the urinary tract.

- Liver and pancreas

They are closely related to the alimentary canal and digestion.
The fish have enlarged livers, some of which are provided with a quantity
It has become so large that it has become an important factor in helping its fish to float in the water.

Fish have a pancreas, which contains those famous cells that produce insulin.

- Fish breathing

Man and land animals each breathe the air in which they live, taking it in and exhaling it from the lungs, deprived of oxygen. Exhaled air, with a lack of oxygen, is carried by the products of the combustion of food in the body, which are carried to the lungs by the blood.

Fish take their oxygen from the water, which is dissolved in it, and take it with their gills, which, as every fish-eater knows, are filaments contained in curved tissues. These wicks, despite their precision, have blood flowing through them, so if sea water enters them and touches the outside of these wicks, the blood inside the wick will absorb the oxygen from it. The water went on its path and sought something else.

Also in the gills, the amount of salt that enters or exits the fish's body is adjusted depending on the water, whether it is sea water or river water. Another exchange takes place between blood and water.

- Heart and blood circulation

Fish have a heart, and the heart has blood circulation.
However, it is a heart that only has one ventricle and one atrium, not two ventricles and two atria like the human heart. The reason for this is that the human blood circulation has two cycles, one cycle from the left ventricle from which purified blood comes out, to the aorta, then to the body’s arteries, then to its veins, then it returns to the heart, to pump it again to the lungs to be purified and then returns to the heart pure. This second cycle (this stage to the lung) does not exist in fish.

The heart of the fish pumps blood to the gills, where it receives oxygen, just as human blood does in its lungs. From the gills, it goes to the cells of the fish’s body (from where it takes oxygen and food) and then to the heart. and so on .

Fish blood has a low pressure, is relatively thick, and is not as fluid as other blood.

A reconciling heart. It is not like the human heart in terms of strength, but it is like it in terms of plan and idea. The plotter is one, and the planner is one. The idea was simplified because the need of fish is not the same as that of humans, and the complexity of fish and the multiplicity of its functions are not comparable to human functions.

Humans are warm-blooded, while fish are cold-blooded, whose temperature is affected by the temperature of the environment
in which you live.

- Urinary Tract

In the published picture of the fish, you find the kidney, and you find
Urine outlet. And the living, that is, alive, as long as it eats food, and the food burns to generate life, and thus combustion produces waste, some of which are solid and some of which are liquid. As for solid matter, its meaning is the anus, and as for liquid matter, its meaning is the urinary tract.

And let's not forget the lungs when mentioning waste. They are in fish gills.

- Fish reproduction

Fish reproduce in great abundance.
Males and females, in the great majority of fishes, those known as bone fishes, do not come into contact during fertilization. Fertilization takes place in open water. The animal throws the egg into the water and the sperm in it fertilizes it.

For example, herring fish gather in large numbers of males and females in the water, and then this water soon becomes abundant with reproductive cells on both sides, and they are fertilized in the water.

Each female herring releases between 30,000 and 2,000,000 eggs per year. Other fish have more uses than what we have previously described.

The reproductive organs are found in males, including the testicles, the semen ducts, and other things, similar to what we know of males.

It is found in females in the form of the well-known ovaries and their ducts.

The male sperm and the female egg come out of the fish from where urine comes out. The same applies to men with regard to sperm (the diagram is one). As for the female egg, it has the uterus and its exits.
The anus in fish precedes the urine outlet in that it occurs in front of it, not behind it, as it does in humans.

- The nervous system in fish

Its appearance is the nerve cord that extends above the column
The vertebral body is the length of the body, and it ends at the front end with a bulge that is the general coordination center that we call the brain.

As for the senses, fish have a sense of sight and a sense of taste.
The sense of smell and the sense of touch. As for hearing, it is not yet clear whether it exists in fish without a doubt.

There is a hadith about feelings, and there are other extensive hadiths as well.
It brings together all of creation, and it is more revealing of the meaning of unity pervading all of creation.