Several causes and prevention of floating head of fish

The "floating head" of fish is a common phenomenon in aquaculture production, and it is also an important sign to judge whether fish get sick or not and the change of water quality. However, many farmers do not understand the cause after discovering the "floating head" of pond fish, and drug administration only based on "experience" is often ineffective and even lead to a large number of deaths. In fact, the floating head of fish can be caused by a variety of factors. According to the cause, "floating head" can be divided into the following three types.

1 anoxic floating head

Anoxic floating head is a "floating head" phenomenon formed by the low content of dissolved oxygen in water and farmed fish swimming to relatively high surface water layer to breathe. This kind of "floating head" has the characteristics of concentrated occurrence time and affecting a wide range of varieties. It usually occurs from 8: 00 am to 8: 00 am in summer. If the degree of hypoxia is high, all fish in the pond will be affected or even die. However, if there is only mild hypoxia, there may only be fish floating heads with high oxygen consumption, and they will return to normal after strong light and high temperature.

Continuous rainy weather, low air pressure and heavy rain in summer all cause floating heads, while the common reasons in the process of aquaculture production are high stocking density and excessive water quality. Although the oxygen released by a large number of algae in fertilizer and water under photosynthesis during the day can make the dissolved oxygen in the water very high, but in the case of no photosynthesis at night, a large number of pond fish, algae and organic matter in fertilizer and water also consume a lot of oxygen and make the dissolved oxygen lower than the tolerance point of fish, causing fish floating head.

For floating-head fish, zeolite powder, Futouling or industrial hydrogen peroxide should be used to rescue the fish, and start the aerator. The main preventive measures are as follows: reducing stocking density, regularly adding clear water to prevent excessive fertilizer of water quality, and starting an aerator at noon on a sunny day to repay the "oxygen debt" of the bottom water, so as to prevent hypoxia at night.

2 floating head caused by ammonia poisoning

This kind of floating head is actually a stress reaction caused by fish poisoning caused by excessive concentration of ammonia in water. This kind of floating head can affect all fish like anoxic floating head. However, because the diurnal variation of ammonia is not as obvious as that of oxygen, the floating head will continue to occur throughout the day, and it is more serious when the water temperature is high in the afternoon. This kind of floating head mainly occurs from early winter to early spring. At this time, a large number of algae die lax, weak photosynthesis, so that the decomposition of residual bait in the water and fish excretion and other ammonium salt can not be converted, resulting in ammonia accumulation, resulting in fish poisoning. For this kind of floating head, we can add new water, turn on the aerator and sprinkle crude salt or bottom water quality improver for first aid, or regularly sprinkle bottom water quality improver or zeolite powder after winter to prevent it.

3 floating head caused by disease

This kind of floating head is due to fish getting sick and swimming alone in the water. Floating head fish are generally scattered in the shallow water near the pool, and there is no obvious occurrence season. The difference between this kind of floating head and the above two kinds of floating head is that the number of floating head fish is small, generally speaking, it is not explosive, because this kind of floating head is caused by disease, so the prevention and treatment should be combined with the prevention and treatment of fish disease.