Fish live in water and suck in dissolved oxygen by gills. A large number of pathogenic organisms in water can easily infect gills, so the incidence of gills is very high. There are many kinds of gill diseases in fish. For accurate diagnosis and rational drug use, gill diseases can be divided into the following six types:
Bacterial gill disease
Symptoms: the gill filaments of the diseased fish are sticky black and covered with dirt, and the gill filaments are severely rotted to expose bone strips. Pathogen: poor water quality stimulates gill tissue and makes fish infected with myxococcus, columnar bacteria or other bacteria.
Prevention and control methods:
(1) Adjust water quality and eliminate germs. First, replenish fresh water frequently; The second is to treat old water with Chaojunjing type A to kill pathogenic bacteria; The third is to stir the water with an aerator to increase the exchange capacity of the upper and lower layers of water.
(2) It is effective to treat with 0.2-0.4 ppm furazolidone, and it can also be prevented by spraying bleaching powder or other oxygen-containing preparations in the whole pool.
(3) Feeding bactericidal bait or mixing with Sanhuang powder and antibiotics.
Fungal gill disease
Symptoms: gill filaments are black and hyphae are attached, which occurs in ponds with aging water quality in high temperature season. Pathogen: gill mold.
Prevention and treatment: thoroughly clean the pond with quicklime, and the sick fish must be destroyed. Malachite green or chlorine dioxide has a certain inhibitory effect on this mold, and the diseased fish pond needs to change a lot of water to improve the water quality.
Insect-borne gill diseases
Symptoms: Overwintering fish often get sick because of their weak constitution and unclean water quality after being civilized in early spring. Spring-sown fish often swim in groups by the pool or downwind, and most of them are parasites such as trypanosoma and calicivirus under the microscope. In summer, the fish pond is sick, and the common fish float on the water in sunny days, which seems to be anoxic and floating. After domestication, it will spread out and continue to float on the water. If you don't feed or eat for a while, your appetite will drop obviously and your growth will be slow. When the gill cover of diseased fish is lifted, tissue hyperplasia and mucus increase can be seen.
Pathogen: It is caused by a large number of parasites such as rotifer, Cryptomeria branchialis and trypanosoma.
Treatment:
(1) When autumn slices enter the overwintering pond or spring slice sub-pond, soak the fish species with the comprehensive soaking agent.
(2) Sprinkle 0.5ppm copper sulfate and potassium permanganate on the whole pond.
(3) Spray the whole tank with 0.7ppm copper sulfate and ferrous sulfate.
Trematode gill disease
Symptoms: Ill fish are impatient, often jump out of the water, or "fry" during eating, with swollen gills and adhesion. Pathogen: It is caused by a large number of parasites of monogenetic trematodes, such as Dactylogyrus, third generation worms and Chinese fleas, and is often complicated with bacterial gill rot.
Treatment:
(1) Trichlorfon 0.5- 1ppm overflowed from the whole pool.
(2) The whole pool can be sprayed with 0.3-0.4 ppm of Chaojunjing Type A, and other fungicides such as bleaching powder, chlorhexidine and chlorine dioxide can also be used to prevent secondary bacterial infection.
(3) Injecting some fresh water the next day after taking the medicine is beneficial to the recovery of fish appetite.
Hemorrhagic gill disease (hemangioma)
Due to poor water quality, blue bath flooding, high ammonia content in water, chemical pollution, pesticide stimulation and other reasons, branchial microvessels have organic lesions, forming aneurysms, which can be identified by microscope.
Prevention and control methods:
(1) Change water in large quantities or apply water quality improvers to adjust water quality.
(2) Spraying 0.2-0.3 ppm furazolidone in the whole pool to prevent secondary bacterial infection.
Dietary gill disease
Symptoms: gill filaments are bent, gill lamellae are bent, atrophied and irregularly arranged. Etiology; Due to insufficient pantothenic acid or other nutritional imbalance in feed, the immune ability of fish decreases, which is easy to cause bacterial infection and parasite invasion.
Treatment: Feed should be formulated reasonably to achieve the balance of amino acids, unsaturated fatty acids, calcium scale, vitamins, trace elements and multiple nutritional indexes.
Due to carelessness in fishing and transporting ornamental fish, the skin of fish is injured, or parasites invade and destroy the skin. The spores of mold invade the wound, absorb nutrients and germinate quickly. One end of the mycelium goes deep into the muscle, and the other end grows outward, forming a cotton-wool mycelium. When mold is only parasitic, it is not easy to be found by naked eyes; When visible to the naked eye, mycelium has invaded from the wound of fish and grown from the outside to the inside. Mycelia entangles and adheres to the wound tissue, causing tissue necrosis. Due to more and more cotton-wool hyphae, the fish body is overloaded, which makes swimming abnormal, loss of appetite and emaciation, leading to death.
When infected with mold, it is also affected by the length of light. Continuous rain for a long time, or insufficient indoor lighting, sunlight and other light sources will promote the growth of mold. The skin of fish infected by mold is usually covered with a layer of white, especially black and red fish, thus losing the luster of fish. Subsequently, the activity is slow, often dull, floating on the water. If not treated in time, the mold of fish will spread, the muscles of the affected area will rot, the appetite will decrease, and eventually it will lead to death.
[Treatment] Dermatomycosis can occur all year round, especially in early spring and late winter. In order to prevent the occurrence of water mold, attention should be paid to prevent fish from being injured and bitten by parasites, and a small amount of salt can be put in the water to inhibit the occurrence of water mold. When fish are found to be infected with water mold, they can be soaked in 3% salt solution, 1 time every day, 5 ~ 10 minutes each time, so as to inhibit the growth of mold. Raise the water temperature to 32 degrees to inhibit the growth of water mold. It is best to install a 15W ultraviolet lamp on the top of the aquarium and irradiate it for several hours every day, which can effectively inhibit or eliminate the breeding of water mold.