The fish are coming to the surface from the bottom of the river, which is a sign of something

1. There are the following possibilities for fish to always surface:

1. Some fish have a habit of being near the surface of the water and rarely going to the bottom, such as toothed butterfly fish.

2. When the dissolved oxygen content in the water is less than 3 mg per liter, most fish will float due to lack of oxygen, and need to increase oxygen and change the water in time.

3. Chlorine poisoning, ammonia poisoning, nitrite poisoning, fish will also float due to lack of oxygen, and need to increase oxygen and change water in time.

4. Infectious gill damage, weakened respiration, fish will always surface, and it is necessary to prescribe the right medicine.

2. Although fish are the lowest vertebrates, they already have quite complete organ systems such as bones, muscles, digestion, circulation, respiration, excretion, reproduction, and neurosensory, and can carry out extremely diverse life activities. In addition to being related to phylogeny, its morphological structure also reflects its adaptability to the water environment.

Judgment of the weight of the fish floating head.

1. The time when the floating head starts The floating head starts to be frivolous at dawn. After sunrise, phytoplankton photosynthesize to produce oxygen, and the dissolved oxygen in the water increases, and the floating head may gradually disappear. If it starts in the middle of the night, it is a heavy floating head, and the dissolved oxygen in the water at night decreases but does not increase, and there is still a long time before the sunrise of the next day, the floating head will only become more and more serious, and even flooding the pool.

Second, the scope of the floating head of the fish in the pond ** part of the floating head is a light floating head; If it is extended to the edge of the pond, there are fish floating heads on the entire surface of the pond, which is a heavy floating head.

3. Reaction when frightened The floating-headed fish sinks when it is slightly alarmed (high-five, or irradiates the pool surface with a flashlight in the liquid), and then floats after a slight stop, which is a slight floating head; If the fish does not sink when frightened, it means that there is an extreme lack of oxygen in the water, and it is a heavy floating head.

Fourth, the types of floating head fish Hypoxic floating head, the order of various fish is different: tilapia, bream, bream floating head, wild trash fish and shrimp floating head on the shore, for mild floating head; The floating head of silver carp and bighead carp is a general floating head; The floating head of grass and herring is a heavier floating head; Carp floats are more severe; If grass carp or herring are on the shore, stranded in shallow water, unable to swim, pale and die, it means that the pond is about to start flooding.

Floating head**.

There is a certain omen before the fish floats, and it can be **.

1. Weather According to the weather forecast and the weather conditions of the day**. Thundershowers in the evening, cloudy and rainy, foggy or sunny for a long time, may cause the next morning to float.

2. Season From April to May, when the weather changes, the fish are prone to dark floating heads; It is easy to float in the rainy season; Drastic changes in the weather in summer are prone to cause floating heads.

3. Fish feeding When inspecting the feeding ground, it was found that the bait was not eaten within the specified time, and no fish disease was found, indicating that the oxygen conditions in the pond were poor, and floating heads may occur.

Prevent floating heads. 1. Apply biological fish fertilizer 2-3 kg of biological fish fertilizer per mu of water surface per month, which can effectively increase the amount of dissolved oxygen in the pool water and prevent floating heads. Bio-fish fertilizer should be soaked for 5-6 hours before application.

2. When the floating head may occur, stop fertilization, control the amount of bait, and take aeration measures.

Rescue the floating head. The dark floating head often appears in the early stage of feeding, and it is also the first floating head of the pond fish, so it is necessary to fill new water or start the aerator in time, otherwise, the fish will die one after another because the fish has not yet adapted to the anoxic environment.

Generally, after the water temperature starts to float at 25-30, it can be delayed for 2-3 hours to increase the oxygen is not dangerous, and the water temperature is above 30 and the floating head must be taken immediately after 1 hour.

When the heavy floating head occurs, the aerator should be used to increase oxygen (5-10 acres of water surface with a 3 kilowatt impeller aerator) or a large-diameter water pump to add water, and the water sprayed by the pump should be flushed out to form a water flow, so that the floating head fish can gather at the water flow with higher dissolved oxygen to avoid dead fish in the pond.

If there is no aeration equipment, the temporary first aid measures are: splash yellow muddy water and salt water into the pool; Yellow mud water plus urine, salt water, alum water, gypsum powder, etc. Through the above measures, the suspended organic particles and colloids in the water can be condensed and precipitated, so as to reduce the consumption of dissolved oxygen and reduce the harm of floating heads.

This indicates a lack of oxygen in the water! It is also a sign that the atmospheric pressure will drop and a storm will come.

When the rain approaches, the weather is dreary and dreary.

The amount of dissolved oxygen in the water decreases, so the fish float to the upper surface or even the surface of the water to breathe.

Due to vigorous aeration and other reasons, the amount of molecular oxygen dissolved in the air into dissolved oxygen in water increases significantly, which makes the dissolved oxygen in the water supersaturated. The content of dissolved oxygen in water is closely related to the partial pressure of oxygen in the air and the temperature of the water. Under natural conditions, the oxygen content of the air does not change much, so the water temperature is the main factor.

The lower the water temperature, the higher the amount of dissolved oxygen in the water.

There is oxygen in the water for the fish to breathe. Before the rain, the atmospheric pressure decreases, and the dissolved oxygen in the water is pressed out of the water by the low atmospheric pressure, so the dissolved oxygen in the water decreases. The oxygen in the water is reduced, and the fish have difficulty breathing in the water, so they have to float to the surface to get enough oxygen.

Before the rain, the atmospheric pressure decreases, and the amount of dissolved oxygen in the water decreases, making it difficult for fish to breathe in the water, so they can only float to the surface to get enough oxygen.

In addition, too much organic matter in the water will also consume too much oxygen, causing the fish to surface.

There is a lack of oxygen underwater, so it goes to the surface of the water to breathe.

Summary. Hello, the fish live in the water, which shows that the fish like the water and cannot do without the water, which is mainly determined by the fish's own respiratory organs and breathing patterns. Since the respiratory organs of fish are gills, and water is denser than air, it is only in water that the gill plates, gill filaments, and gill patches of the fish can be fully opened.

By increasing the contact area between the gills and the water, the chance of taking up dissolved oxygen in the water increases the chance of obtaining more oxygen. Once out of the water, the water on the surface of the gill plates is quickly evaporated, and the fish lose the ability to take in oxygen and cannot survive. So, the fish have to live in the water.

Hello, brood fish live in water, which shows that fish like water and can't do without water, which is mainly determined by the fish's own respiratory organs and the way they breathe. Since the respiratory organs of fish are gills, and water is denser than air, it is only in water that the gill plates, gill filaments, and gill patches of the fish can be fully opened. By increasing the contact area between the gills and the water, the chance of taking up dissolved oxygen in the water increases the chance of obtaining more oxygen.

Once out of the water, the water on the surface of the gill plates is quickly evaporated, and the fish loses its ability to take in oxygen and cannot survive. So, the fish have to live in the water.

There is another reason why fish can swim fast and well. The main "swimming tool" of fish is the fin, the fin is the perfect swimming tool that the fish has evolved into after living in the water for a long time, the fish generally have a tail fin, dorsal fin, pectoral fin, and pelvic fin, of which the dorsal fin is specially used to master the balance, and the other mackerel is used to paddle and master the direction, when the fish swims, just like people use the rudder and oars when rowing, the use of various parts of the fins is very coordinated, which is easier than people walking. In addition, most of the fish are pure and sharp at both ends, and the middle is wide, which can effectively reduce the resistance of the water, and swim up to accompany the fast and light to make it loose.

Fish, like other animals, must have oxygen to survive, and most animals on land exchange gas in the lungs after breathing, so as to expel some waste gases (mainly carbon dioxide) from the body to obtain the oxygen needed for life. Fish living in water bodies do not have lungs, and their gas transfer during respiration is mainly done by gills, to be precise, small pieces of gills on the closed gill filaments. There are many gill filaments in the gill part of the fish, there are many gill filaments on both sides of each gill filament, and there are many capillaries in the gill filaments, and they are very soft, so it is necessary to rely on the buoyancy of the water to fully open, so that the contact area between the fish and the water reaches the maximum, which is conducive to gas exchange in Chunzhen.

This statement that "a thousand years of fish roe, where there is water, there is fish" is not correct.

Water doesn't give birth to small fish on its own.

There are several possibilities for fish to emerge from the depression after it has been waterlogged for a long time.

1 There were fish in this place, and these fish would spawn before the drought came, and bury their eggs in the mud, and the broodstock would die because of the drought, but the eggs would live for a few months, and when the next rainy season came, the small fish would hatch.

2 Because of the heavy rains, the nearby fish pond was flooded, and the fish or eggs in it were washed out and hatched or grown in the depression.

3 Because a number of birds or other animals go to the water's edge to fish, and bring the eggs to the depression, the eggs hatch into small fish and grow in the depression. This is also one of the methods of fish transmission.

If you put a tank of water in a large tank, no matter how long it takes, small fish will not hatch. Therefore, it is wrong to say that where there is water, there are fish.

This statement that "a thousand years of fish roe, where there is water, there is fish" is not correct.

Water doesn't give birth to small fish on its own.

After a long period of water accumulation in the depression, there will be fish, which is possible for several potato base species.

1 There were fish in this place, and these fish would spawn before the drought came, and bury their eggs in the mud, and the broodstock would die because of the drought, but the eggs would live for a few months, and when the next rainy season came, the small fish would hatch.

2 Because of the heavy rains, the nearby fish ponds were flooded, and the fish or eggs in them were washed out and hatched or grown in the depressions.

3 Because birds or other animals go to the water's edge to fish and bring their eggs to the depression, the eggs hatch into small fish and grow in the depression. This is also one of the methods of fish transmission.

If you put a tank of water in a large tank, no matter how long it takes, small fish will not hatch. Therefore, it is wrong to say that where there is water, there are fish.

No, when the water is clear, there are no fish. Where there is water, there are not necessarily fish. However, some fish eggs can live alone for a long time.

For example, the fertilized eggs of crucian carp can survive for up to a year in dry conditions. The early jujube seedlings of some fish may swim with the water, so it gives people the illusion that there are fish when there is water.

The proud fish will say, "If I am not willing to come up, I will not come up in any way you want to catch me."

The shy fish will say: I hate it, people won't fish it for you so easily, so that people are thinking about it.

The greedy fish will say: Cut, just like this little meat to try to trick me, it's too naïve, at least give me a big portion.

Smart fish will say: hehe, boring. (Then calmly swim past).

Stupid fish will say: look, look, someone wants to fish us, we give them a catch.

1: Higher. Because it is funny, it is reflected from the human body and refracted by the water.

2: Cons or long-distance leasing refers to the following. Ditto.

The fish looks at the people on the shore from the water, slightly higher than the actual position of the people; The person on the shore looks at the fish, slightly higher than the actual position of the fish, and the person who looks at the person on the shore from the water has grown taller, (the angle of incidence is less than the angle of reflection).

The people on the shore look at the fish, but in fact, the fish looks at the position below the key group Qinjian, (the angle of incidence is greater than the angle of reflection).

The angle of incidence is less than the angle of reflection (the angle of incidence is greater than the angle of reflection) is different, but the answer is the same if you look up and look down.

b The biosphere provides the basic conditions for the survival of organisms, that is, nutrients, sunlight, air and water, as well as suitable temperature and a certain living space Fish must live in the water and die after leaving the water for a period of time, indicating that the survival of organisms depends on certain environmental conditions.