Common Fish Diseases: How to Avoid Them
Types of Fish Diseases
According to Wikipedia, fish diseases are similar to diseases in humans and other animals. There are two types of fish defenses against disease: specific and non-specific. Non-specific defenses include skin, scales, and the mucus layer produced by the epidermis. This mucus traps microorganisms in the skin and inhibits their growth. Fish can become irritable if pathogens infect their bodies. This causes them to produce white blood cells to try to kill the pathogens.
The temperature rises gradually with the arrival of spring. This increases the growth of harmful bacteria in fish tanks. The water temperature rises and summer arrives. This is the best season for fish growth.
Due to high summer temperatures, weak fish after overwintering and vigorous metabolism, there is a tendency to deteriorate the quality of the substrate and pond water. This can lead to various fish diseases. These can easily cause water mold, water erysipelas and bile duct disease. Here are some examples of common fish diseases.
1. Water Mold Disease
Water mold disease is an infection caused by water damage to freshwater fish’s surfaces due to factors like straining and freezing. The causative agent can be found in large quantities in the water column. It is an opportunistic disease. The water mold can infect fish bodies by reproducing sexually. It forms white flocculent material that sticks to the fish’s body. Fish become irritable and have a decreased appetite. They also lose their ability to move normally. Other infectious diseases can be easily infected. Fish will quickly die if they are not treated promptly.
2. Red Skin Disease
Similar to water molds, erysipelas can occur in a similar way. It’s usually caused by factors like net pulling or frostbite that cause damage to the fish’s surface and infect with Pseudomonas fluorescentens. Pseudomonas Fluorescens, an opportunistic parasite, is also found in the water column. Infection is rare if there isn’t any damage to the fish’s surface.
Pathogenic bacteria can enter the fish if there is visible damage to the surface. They will multiply in the affected area, causing clinical symptoms. The disease will cause severe inflammation and swelling of the fish’s body. Scales will fall off and fin tissue will become a “broom shape”. If the disease progresses, the fish will become infected with a lot of water molds. The scales and fins will fall off, leading to severe symptoms and higher mortality. This disease mostly affects grass carps, herring carp, and crucian cars.
3. Vertical Scale Disease
Vertical scale disease manifests itself in the form of fish scales that open up and fall off under light pressure. There is also liquid overflow. The fish’s abdomen will swell, lose balance, and eventually dies. It’s most common in low temperatures or in short periods of temperature change.
4. Oblique Tubeworm Disease
Oblique tubeworm disease manifests as a large amount of mucus secreted by the affected fish. This creates a white layer of mucus on the body’s surface. Chinstrap worms can multiply if the water temperature is right. They can cause mass mortality in as little as 2 days.
5. Bacterial Putrefaction
Descaling, inflammation and congestion of a portion or all of the fish’s body; descaling; congestion at the fin bases; destruction of the tissue between fin bars; erythema frequently appearing on the zygomatic and upper foreheads. Sometimes, the zygomatic bones may also decay to expose the zygomatic. It is most common in the late spring and early part of summer. The diseased fish die quickly and swim slowly, sometimes alone, on the water’s surface.
What are the Causes of Fish Diseases?
- Fish farmers can pursue economic benefits in order to increase their breeding density, which will increase the likelihood of developing disease. As a result of increased farming density, more baiting is done. This causes a lot of pollution to build up in the bottom of a pond. This can lead to a decrease in oxygen availability, which in turn leads to a higher level of nitrites, ammonia and other harmful substances. It becomes easier for fish diseases to be eradicated.
- Fish illness is also a result of eating spoiled, unnutritionally complete or moldy feeds. Regular use of antibiotics, feeding moldy or spoiled feeds, can lead to malnutrition, pallor, gall bladder swelling, and discoloration of the lesioned areas. This can cause poor quality fish and reduced susceptibility to various diseases.
- Poor water quality, increased pollution, pond hypoxia, ammonia and other harmful substances increased. This can lead to increased mortality rates and higher breeding costs.
- Split-pond stocking can cause damage to the fish’s bodies, which could lead to bacterial invasion. These fish diseases include water mold, vertical scaling disease, gill rot and red skin disease.
- Overwintering makes the fish weaker in spring. This is when parasites can multiply and infest cultured fish. One way to do this is to infiltrate the gills and cause inflammation and decay of the filaments.
How to Prevent Fish Diseases
1. You can adjust the amount of food you give depending on the weather and water quality. Feed insists on the use of full-priced compound feeds from regular producers. You must use fixed-point baiting and build a table to monitor the fish’s eating habits.
2. Water quality adjustment is important. You should replenish your water every 7-10 days. To promote sludge degradation, turn the aerator on regularly. On sunny days, stirring is best done at noon. When the temperature is high and the air pressure drops, stirred should be stopped
3. Mechanical damage should be minimized when transporting fish fry from the pond. Choose fry that are strong, active, and with neat specifications when purchasing them. Before entering the pond, it is important to disinfect them. To disinfect the pool, you should use either physiological saline solution or potassium permanganate.
4. The bottom of fish ponds should be cleaned regularly, approximately every 10 to 15 day depending on its condition. Keep your fish pond clean and free of parasites. This effectively prevents parasites multiplying.
Prevention and Treatment of Fish Diseases
1. Saprolegnia diseases
Prevention Of Fish Diseases
This disease can be reduced by thorough cleaning the pond with quicklime. When stocking fish, it is important to not injure them. Before stocking fish species that have been transported long distances, disinfect them with 2% to 33% brine or disinfectant.
Treatment of Fish Diseases
Spray the disinfectant on sunny days. Spray disinfectant two hours prior to disinfection if fish are not well-energized. After lunch, heat the disinfectant solution in 70°C for 30 minutes. Then sprinkle the solution evenly on the entire pool. Sprinkle 15 pounds of salt on each mu.
2. Red Skin Disease
Prevention Of Fish Diseases
Fish should not be damaged during transport, catching and stocking. The fish can be completely soaked in an iodinated disinfectant and left to sit for up to 30 minutes before being put into the fry. If the fish are unwell, you can spray the whole pond with an Iodinated Disinfectant.
Treatment of Fish Diseases
Sprinkle lime 10-15kg/mu into the tank. Chlorine dioxide powder 0.25kg/mu is added once a day, 3-4 times a row. Mixture is added to 100 lbs per bag. The water depth should be 3-5mm. Dosage can be adjusted according to the needs.
3. Vertical Scale Disease
Prevention Of Fish Diseases
Stocking fish in separate ponds is a good idea. It’s best to avoid injuring them and kill parasites as soon as possible. To prevent this from happening, spray the entire pool with a chlorine-based disinfectant. Before releasing the fry, soak them in 3-5% brine.
Treatment of Fish Diseases
Sprinkle 1.5-2kg/mu bleaching powder every other day, 3-4 days in a row. Sprinkle 100 kg of the mixture on the tank.
4. Oblique Tubeworm Disease
Prevention Of Fish Diseases
Quicklime can be used to clean the pond and kill any pathogens on the bottom. Before stocking, soak the fry for 20 minutes in 2% brine
Treatment of Fish Diseases
For 5-7 days, 200 kg of Roundup ingredients can be used per bag. Sprinkle Roundup evenly over the entire pool. Add 3-5mm of water to each bag for 2-3 days. Adjust the dosage as necessary.
