Every year in the winter and spring low temperature period (about December to March of the following year), there is a phenomenon that particularly causes fish farmers a headache, selling fish and buying fish in the pond is many people, but often this time fish are particularly prone to outbreaks of injury after the rot, congestion and its red skin, water mold disease is quite serious, and then a large number of dead fish, we temporarily call fish low temperature injury syndrome, this "plot" is staged year after year.
(Water mold)
First, the cause of dead fish in winter and spring
Every year in the winter and spring season, everyone is used to fishing in nets and selling fish and buying fish in the pond, in reality, many people feed good fish, but many people can't get fish. In the aquatic industry, everyone thinks that the low temperature of the winter is good luck fish, but the loss caused by a slight accident of fish injuring and killing fish every year is not small. Most of the reasons are due to unskilled operation technology, barbaric fishing, not fine fishing in the net, choking fish in muddy waters, or too much density of loading fish like marketed fish, or deteriorating water quality, or long-distance long-distance fish, or too long-distance drainage when weighing, etc. These improper operations do not matter if the fish are sold as edible fish on the market, but if they are re-raised, it will be annoying.
(Serious trauma to the fish body)
Many fish farmers feel that there are many fish and fish prices are low at the end of the year, a large number of ponds are also concentrated in opening ponds to sell fish, sold today and sold tomorrow, the number of net pulling times, the fish body tossing and injury is of course serious, in this case, the purchased fish is used for fry re-breeding, the natural low survival rate is very inevitable. These fish reared in the lower pond after being tossed, or after the pond was transferred or after the fishing (the mud flooded the pond water and then did not deal with it), at first coincided with the low temperature pathogenic symptoms are not obvious, very hidden people unconscious. Perhaps when the water temperature rises in the spring, or when the temperature drops sharply and causes severe stress to the fish, the incidence of the pond will also increase, which will start to be onset and difficult to treat.
In fact, after so many years of experience and observation, the lowest temperature season is the most suitable for the fish fry to be put into the pond, and the possibility of fish being cured after serious injuries in the low temperature period is very small or even incurable, if the onset of the disease after injury is mostly dead and alive. It happens every year, every year it is said, but it happens every year, and every year it buys fish and suffers every year, and this lesson should be very profound. Sometimes the fish injury is not obvious, but there are also hidden injuries, such as internal injuries, loose nails, debonded coarse nails, no obvious epidermal scars and nail removal, etc., when the conditions are unfavorable, it will cause chronic inflammation of the injured site, and the low temperature period of about two months may occur, resulting in chronic disease of fish, making people invincible.
(Acne disease: paraffin-like hyperplasia on the body of the diseased fish after the injury)
Second, the possible avoidance of fish low temperature injury syndrome
Of course, it is not that the end of the year and the beginning of the year can not buy fish under the pond, it should be noted that it is best to buy a winter to the end of the feeding fish, short-distance fish, net fish or cage fish, healthy fish (not thin fish, disease-free fish), reasonable transportation of fish, to find a very experienced and responsible fish farm to buy fish is more appropriate. Try not to buy long-distance fish (fatigue and weakness), clear pond fish, lakes, rivers and reservoirs and other large surface fish (such fish are rarely disturbed in wide water bodies) and so on. There is also a key point is to pay special attention to the vigilance of casualties after the fish go down to the pond, at least to do a good job of caution before going down the pond, after the pond to prevent the use of medicine, when the fish can eat the feed as quickly as possible to feed the opening, do not until the fish begin to die before the hurry, ask the east and the west is also too late, I am afraid that there is a magic hand rejuvenation technique is also difficult to treat.
The above two figures: the scooping tool in the upper picture is easy to hurt the fish; the lower picture scooping the fish tool does not hurt the fish.
After the fish are caught, the fish will secrete a lot of mucus, coupled with the water body when pulling the net, resulting in turbidity, the fish jump violently, the stress response of panic and fright, the state of adaptation is large, the heartbeat is accelerated, and the oxygen consumption rate will increase rapidly, so after fishing (lifting the net, the same reason for the cage) to slow down the fish in the net for a period of time (but the density of the fish in the net should also be appropriate) or rinse the fish body with water, called "temporary breeding", which can accelerate the elimination of feces on an empty stomach, And rinse off the mucus secreted on the fish body and the turbid liquid produced by the stress response of the fish due to fishing and operation, especially the attachment dirt on the gills, which is conducive to the fish gradually adapting to the dense state, restoring the physique to improve the stress adaptability and increase the transport resistance.
(Comparison: Body trauma and body surface dearification of the next fish)
Also, try not to buy big fish, the bigger the fish struggle, the more fierce the more vulnerable to injury, the largest number of big fish die every year. In fact, the appropriate size of small body fish can also reach the market specifications in a production cycle (for example, grass carp fry of about 10 cm can also grow to more than 2 catties that year), and the breeding efficiency is much higher than that of larger fish, because the fish farming efficiency and the weight gain multiple of the fish are particularly related, that is, the larger the weight gain multiple of the fish, the higher the breeding efficiency.
(Canker disease caused by a scraping wound on the head of a fish)
Head injuries to fish are mostly caused by fish injuries. Fish tail injuries are mostly when the scale is crossed, the fish swing fiercely, the tail pulled up on the edge of the barrel mouth scratched the most likely. When everyone buys fish, the most focused is: when the fish passes the scale, it is fiercely delayed in draining, and I am afraid that the water will take up the weight, but in fact, at this time, the dried fish has to shout for help (but we can't hear it), which is the most dangerous link. When the fish body is pressurized by each other for a long time, this is the same as that of humans, which will cause poor blood flow of the tissues at the pressure site, which is easy to cause atrophy and necrosis of the body tissues. In the case of little or no water in the container of the fish turning tool or over the weight of the weighing, the fish and the fish are piled up and squeezed against each other, and the manifestation of this fish injury is that the base of the pectoral fin or the base of the ventral fin often appears to be congested and ulcerated, which is because the fish support the body with the pectoral fin and the ventral fin or fin when under pressure, and bear the heavy pressure of the accumulated fish. Even if you see that there is no injury at that time, it is easy to have internal injuries (hidden injuries). The fish should be scooped and drained quickly, and then the fish should be poured and weighed in a bucket filled with water. There is also the most overlooked is the physical problem of fish, many people in the autumn early to stop feeding or poor physique of the fish do not buy as well.
(Unfavorable: Hypoxia in the dense state of the fish)
If we were to treat fish as human beings, many problems could have been avoided. Whether the fish is injured or not, it is advisable to take medicine to prevent it, and do not listen to those "low temperature and no medicine" saying. Try to bring water through the scale and carry water to load the fish, so that there will be no injuries and deaths of fish or at least reduce the chance of injury to the fish body, thereby improving the survival rate.
(Disadvantage: Fish frightened and panicked)
In addition, try to avoid the outbreak of water mold fungus temperature stage (water temperature below 18 ° C) to move the net to buy fish and sell fish, after March or before November of each year is the most appropriate, because at this time to buy fish even if the fish is injured and injured, most of them are red skin disease, ulcer rot disease and other categories, compared to water mold These diseases are much easier to treat in treatment, and the possibility of cure rate is much greater.
(Long hairs on the wound --- water mold)
Third, fish low temperature injury syndrome --- complications of red skin water mold
Fish low temperature injury syndrome, can also be called red skin water mold complications, fish in the low temperature period after the onset of injury, early red skin disease (still can be treated), later water mold disease (severe time no help), that is, first there is a wound of red skin disease, and then on the wound to breed water mold, during which can also be complicated by ulcer disease, acne disease, herpes disease, furuncles, etc., of course, may also be secondary to low temperature insect pests such as parasitic oblique tube worms, gill mold and so on. The chain of formation of fish hypothermia injury syndrome is: fish injury + germ infection = erythroderma + fungal infection = water mold = formation of red skin water mold complications.
(Disadvantage: Fish choking on muddy waters)
The symptoms of fish low temperature injury syndrome are roughly as follows: swimming abnormalities, floating does not sink, sluggish movements, obvious skin lesions in the early stage, skin ulceration, congestion and bleeding, obvious scars, lack of scales and nails, fins rotten, head injury mouth rot, etc., in the later stage of the water mold pathology is obvious, in the head, snout, tail, trunk or fins of the fish, sometimes even in the gills there are water mold (that is, trichome) parasitism, and finally exhaustion and death.
(Red skin disease: dearmorrhage, fins and fish body congestion)
Fourth, the treatment of fish low temperature injury syndrome
When fish cryogenic injury syndrome occurs, if the fish is seriously injured, there is basically no medicine to save. The promotion of drug treatment is to have a certain therapeutic effect on some fish that are very lightly injured and in the early stage of erythroderma, if the fish's wound has not yet grown water mold, there may be time to treat, perhaps there is a glimmer of hope. All fish diseases with serious trauma, should pay attention to the course of treatment, the course of treatment is the same as people who have seriously ill hospitalization, continuous medication for several days or even ten days before the line, not sloppy at all, try to use the "external use + internal administration" method, do not think of it, forget to use it, these are useless.
(Bleeding phenomenon of internal injuries in fish)
Some people say that a certain drug has a particularly good effect, admitting that some drugs do work very well, but there is an illusion to pay attention to, and the effect of some drugs is often a coincidence. Sometimes after a long time of dead fish, the damn fish is almost dead, and it just so happens that the amount of dead fish is reduced after using this medicine, and it is considered that this medicine has a special effect. This is also the best explanation for a certain drug that seems to be effective in this home, but does not work in another household.
In addition, the now banned malachite green, its efficacy has been artificially exaggerated and mythologized, and the effect is not satisfactory when used to treat water mold disease, and now it has become an excuse for the aquaculture industry to be criticized and attacked by rumors.
This article synthesizes some empirical treatments as follows, for reference only:
1. Soaking medicinal bath: soaking before the seedlings are planted in the pond: 1-3% salt (or the sticky water mouth can taste slightly salty) or add a few drops of vinegar to soak for 5-20 minutes; put 15-20 grams of potassium permanganate aqueous solution medicinal bath for 15-30 minutes per cubic meter of water; or soak in the bath with other sterilization drugs.
2. Disinfection prevention: After the seedlings are planted in the pond, the whole pond should be sprinkled with 1-2 sterilization and disinfectants for prevention. For example, povidone iodine, benzalkonium bromide, bromochlorohydantoin, chlorine dioxide, sodium dichloroisocyanurate, trichloroisocyanuric acid and the like. Remove the pathogenic source in the killing water body, prevent the water mold disease before the red skin disease (injury caused by disease), even if the seed is injured, after a period of growth and recovery, the damaged fish body can also be restored.
3. Internal use: use pyrolysis, anti-inflammatory and antibacterial drug mixture feeding. For example, three yellow powder, allicin and so on.
4. Salt baking soda mixture: 1 meter water depth per acre of water surface using salt 5 kg plus baking soda 5 kg mixed spill, the next day the use of iodine agent (compound iodine, povidone iodine, etc.), after which you can use salt plus baking soda compound once, it is said that this mixture has a good effect on the prevention and control of water mold.
5. Water mold special drug: thiosefloxacin is a common "water mold net" drug, which has a unique killing effect on the fungi that cause water mold disease in fish bodies, and also has a good killing effect on aeromonas, Vibrio eels, Edwardianella retardation and columnar fibrophilus bacteria; salicylic acid: the chemical name is "o-hydroxybenzoic acid"; dithiocyanomethane: it has a good killing and inhibition effect on water pathogens, fungi, algae and protozoa.
6. Traditional Chinese medicine: five times per cubic meter of water body put 2-4 grams, first grind the five times and then soak it in boiling water, which has the effect of astringent wounds, can prevent and control fish white skin disease, red skin disease, water mold disease and rotten gill disease; 1-2 kg of tobacco leaves per mu of water surface, boil with water for 2 hours, even juice with slag and sprinkle the whole pool; 1 meter per mu of water depth, with camphor essence 3 two, water splashed in the whole pool, 1 time a day, for 3 consecutive days; rhubarb + copper sulfate: rhubarb 2.5-4 g / cubic meter, copper sulfate 0.5-0.7 g / cubic meter of the whole pool sprinkled. Before rhubarb is used, the rhubarb can be used with 0.3% ammonia water according to the ratio of 1:20 (when there is no ammonia water, it can be replaced by ammonium bicarbonate, which can be soaked by 1 kg of rhubarb plus 20 kg of ammonium bicarbonate with water), soaked for 12 to 24 hours to make the anthraquinone derivatives free out to improve the efficacy.
7. Allicin + chlorine dioxide: each mu mixed with 250 grams of allicin plus 250 grams of chlorine dioxide after the whole pool is sprinkled.
8. Strong chlorine + glutaraldehyde: strong chlorine 2 kg / 5 acres, glutaraldehyde 125 ml / mu, the whole pool spilled.
9. Quicklime: When the water quality is poor, the application of quicklime is 20-40 kg per mu of water and sprinkled, which has a good auxiliary effect. According to the study, water mold is more likely to multiply in nearly neutral water, and in the alkaline environment is not easy to erupt, when the pH value > 8.0 or more basically does not appear, it proves that the pH value is related to the occurrence of water mold, according to this, it can be used to increase the pH value by splashing quicklime water.
10. Use other commercially available special treatment of water mold disease and other sterilization drugs. Of course, there are many drugs currently available for the prevention and treatment of red skin disease and water mold disease, but the effect is mostly unstable.
Reprint Statement
Source: Splash fish