CATDOLL : CATDOLL: There have been many dead carps in the fishing pond recently. The gills of the fish have turned white, but there is nothing wrong with their bodies. The water is fresh water brought in from the river. Is there any solution?

1. There have been frequent deaths of carp in the fishing pond recently. The fish's gills have turned white, but there is nothing wrong with their bodies. The water is fresh water brought in from the river. Is there any solution?

Branchiomycosis

The pathogen belongs to the order Blastocladiaceae, family Blastocladiaceae, genus Branchiomyces p. The mycelium of the gill fungus that parasitizes grass carp is relatively thick and straight with few bends. It usually grows in a monopolar and elongated manner with few branches. It does not enter the blood vessels and cartilage, and only grows in the tissues of the gill lamellae. The mycelium diameter is 20-25 microns, and the spore diameter is 8 microns. Another type parasitizes the gills of black carp, bighead carp, and dace. Its hyphae are often bent into a net-like shape, are relatively thin and thick-walled, and have many branches. The branches grow along the gill filament blood vessels or afferent cartilage, and cross-intersect to fill the gill filaments and gill lamellae. The mycelium diameter is 6.6-1.56 microns, and the spore diameter is 6.6 microns on average.

There are no obvious lesions in the early stage. When the spores attached to the gills develop into hyphae, the hyphae continue to extend inward, branch repeatedly, and then branch along the gill filament blood vessels or enter the cartilage, destroying tissues, blocking microvessels, and the gill flaps lose their normal bright red color and become pink or pale. The gill lamellae swell, become congested, and bleed. Sometimes there are punctate congestion or bleeding. As the disease progresses, the respiratory function is greatly hindered. The onset of gill fungus disease is often acute. From the time the pathogen is discovered, if the environmental conditions are suitable, it can multiply in large numbers within 1-2 days, and fish in the pond will randomly and explosively die. The mortality rate is over 60%. The symptoms of the chronic type are not obvious, sometimes manifested as small part of the gills necrosis, and some parts become pale due to blood loss. The ends of the gill flaps of some diseased fish are swollen

2. Prevention and Control (1) Clean and disinfect the pond strictly with quicklime or bleaching powder. Sprinkle chlorine preparations and quicklime alternately every 15 to 20 days during the hot season, especially chlorine preparations. (2) Add new water frequently to improve water quality, reduce organic matter content, and keep the water fresh and rich in dissolved oxygen. (3) Feed and fertilize in moderation. Organic fertilizers must be fermented and decomposed with quicklime before use. Do not apply organic fertilizers during the rainy season. (4) Add clotrimazole to every 100 kg of feed to make medicated bait. One course of treatment is 5 to 7 days. Add multiple vitamins to feed to enhance immunity. (5) Mix Artemisia annua, Acorus calamus, Scutellaria baicalensis, and Isatis indigotica in a ratio of 5:2:2:1 to make a powder, and add 2% of the feed to feed fish. (6) Use a composite biological agent 10 to 40 mg/L to treat excessive ammonia nitrogen in the water body, and mix the agent with bait for feeding to inhibit mold growth. (7) Spray 0.3-0.4 ppm chlorine dioxide throughout the pond once a day for 3-4 times. (8) Add 1% of "Gill Health" to the feed and feed it twice a day for 3 days.

Is it a water source problem?

Is it due to lack of oxygen? It is best to find a professional to help you check it out.

Just based on what you said

Can't tell where the problem is

2. During carp farming, branchial fungus disease occurs. What are the symptoms? How to deal with it?

Branchial fungus disease is a fish disease caused by branchial fungi parasitizing on fish gills. There are two types of branchial fungi found in China. The branchial fungi parasitizing on the gills of grass carp have relatively thick and straight mycelium with few bends. They usually grow in a single branch with few branches. They do not enter the blood vessels and cartilage, and only grow in the tissues of the gill lamellae. The other type parasitizes on the gills of silver carp, bighead carp, and dace. Its mycelium is often bent into a net-like shape, which is thin and thick-walled, with many branches. The branches grow along the gill filaments and blood vessels or penetrate the cartilage, crisscrossing and filling the gill filaments and gill lamellae.

One symptom

In the early stage, the diseased fish will not eat and will circle around the feeding table in groups. In the middle stage, the diseased fish will swim alone and float on the water surface during the day, which seems to be due to hypoxia. The eyes of the diseased fish will bulge out, the body will turn black, and some of the fins will turn white. At the same time, complications such as liver and gallbladder inflammation and enteritis will appear. There will be a lot of ascites in the abdominal cavity, and bleeding in the intestines accompanied by the appearance of yellow liquid.

2. Diagnosis

The diseased fish swim slowly, the gill filaments are swollen, and the mucus on the gills increases significantly. Some fish have spots of bleeding, congestion, ischemia and necrosis, showing a mottled gill appearance. When the disease is serious, the fish is highly anemic and the entire gill is blue-gray. Due to the damage to the gills, the pathogen produces a large number of spores through the mycelium and spreads in the water. The spores come into contact with the fish body and attach to the gills to develop into hyphae. The hyphae continue to grow into the gill tissue, branching again and again, branching along the gill filament blood vessels or penetrating into the cartilage, destroying the tissue, blocking the microvessels, and the gill flaps lose their normal bright red color and become pink or pale. Sometimes there is punctate congestion or bleeding. As the disease progresses, the sick fish does not eat, the respiratory function is hindered, and the sick fish suffocates due to lack of oxygen and dies.

Three responses

1 In the process of treating fungi, you can choose products that inhibit fungi, such as thiophanate-methyl, salicylic acid, povidone-iodine, etc. While treating branchial fungus, it is best to use Chinese herbal medicine and immune enhancers such as astragalus polysaccharide orally to repair the body's constitution and resistance, which is more conducive to the cure of branchial fungus.

2 If the disease is discovered, quickly add new water, or move the fish to a pond with clear water (add another cage or transfer the cage), and the disease will stop.

Symptoms include destruction of cheek tissue, paleness or bleeding and congestion. The way to prevent it is to keep the water clear and not let it deteriorate.

1.

Pathogen: Caused by branchial fungi invading the gills.

2.

Symptoms: The gill tissue is damaged and pale, sometimes a little congested and bleeding, and finally death due to respiratory failure.

3.

Prevention methods:

4.

Always keep the water fresh to prevent water quality from deteriorating.

5. If this disease occurs frequently, do not use manure or grass as fertilizer and use mixed compost instead.

Symptoms: The gills of fish with branchial fungus are pale or pink, with flowery gills, punctate congestion and bleeding, and in severe cases, the entire gills are grayish white. Further development, hyphae cover the fish gill tissue, block blood vessels, and seriously hinder the breathing of fish, causing breathing difficulties and loss of appetite. A large number of deaths may occur after a few days. How to deal with it: 1. Clean the pond thoroughly and maintain good water quality to prevent the growth of branchial fungus. 2. Strengthen water quality management and regularly apply Yushi Bacteria to maintain bacterial balance and inhibit the growth of harmful bacteria such as branchial fungus. 3. Change the water quickly after the disease occurs, and change 20-30% of the water depending on the water temperature difference.

3. What is fish gill flap? It refers to tropical fish

Fish gill diseases can be divided into bacterial gill rot, fungal gill rot (also known as gill mold disease), and parasitic gill disease according to their pathogenic pathogens. Bacterial gill rot is a common infectious fish disease, often complicated by bacterial enteritis and red skin disease, which seriously harms grass carp species and adult fish. Once an outbreak occurs, the mortality rate of grass carp is as high as over 60%, and it also seriously threatens black carp, silver carp and bighead carp. In recent years, with the rapid development of high-density and intensive breeding methods, famous and excellent species such as carp, eel, mandarin fish, tilapia, spotted forktail, California bass, etc. are also seriously infected with bacterial gill rot, and the mortality rate is often as high as over 40%. Fish gill disease seriously affects the further development of aquaculture. Aquatic workers have conducted a lot of research on this disease and have summarized a set of effective prevention and control technologies.

1. Pathogens

1. Bacterial gill rot: The pathogen of bacterial gill rot is Myxococcus. The bacteria are slender, soft and easy to bend, with basically the same thickness, about 0.3 microns, blunt at both ends, usually slightly curved, sometimes curved into a semicircle, circle, U-shape, V-shape and Y-shape, etc.; but the shorter bacteria are usually straight, 2 to 4 microns long, and some are as long as 37 microns. Generally, they reproduce by transverse fission, splitting into two individuals of roughly equal length. This bacterium has no flagella and usually glides or shakes. It grows well at a pH of 6.5 to 7.5, poorly at pH 8, and does not grow above pH 8.5 and below pH 6. The optimum temperature is 25℃ for good growth, but strong toxicity; 18℃ for slow growth and strong toxicity; 33℃ for good growth, but poor toxicity; 40℃ for slow growth and very low toxicity; 4℃ for no growth, and 65℃ for death in 5 minutes. The growth of this bacterium can be inhibited if the culture medium contains more than 0.7% salt. This bacterium grows facultatively aerobically and can also grow under anaerobic conditions, but it grows slowly and reproduces less frequently.

2. Fungal gill disease (branchial mycosis): The pathogen of branchial mycosis is branchial mycosis. The branchial mycosis parasitized by grass carp has relatively thick and straight mycelium with few bends. It usually grows in a monopolar extension with few branches. It does not enter the blood vessels and cartilage, and only grows in the tissues of the gill lamellae. The diameter of the mycelium is 20-25 microns, and the diameter of the spores is 8 microns. Another type parasitizes the gills of black carp, bighead carp, and dace. Its mycelium is often bent into a net-like shape, which is thin and thick-walled, with many branches. The branches grow along the gill filaments and blood vessels or penetrate the cartilage, crisscrossing and filling the gill filaments and gill lamellae. The diameter of the mycelium is 6.6-1.56 microns, and the average spore diameter is 6.6 microns.

3. Parasitic gill disease: Gill maggot disease, the pathogen of which is the Chinese giant carp. The female body is slender, cylindrical, milky white, and divided into three parts: head, thorax, and abdomen. The head is slightly triangular, with 5 pairs of appendages, of which the second pair of antennae has become a long and thin hook to attach to the gill filaments of the host. The thorax has 6 segments, the first 4 segments are slightly wider than the length, and the 6th segment is the smallest, called the reproductive segment. When the female matures, there is a pair of slender white egg capsules on the reproductive segment, which can be seen with the naked eye. The abdomen has 3 segments, which are slender. The total length of the female is 2.2 to 3.0 mm. The male lives freely; Tail-up disease, the pathogen of which is the silver carp Chinese giant carp. The female body is cylindrical, milky white, but shorter and thicker than the Chinese giant carp. The body is divided into three parts: head, thorax, and abdomen. The head is slightly blunt rhombus-shaped, and the second pair of antennae have become short and wide hooks. The thorax has 5 segments, the first 4 are wide and short, the 5th segment is very small, and the rest are similar to the Chinese worm. The female is 1.9 to 2.7 mm long.

Fish gills