CATDOLL : CATDOLL: Sporozoan diseases in fish

First, identify the type of disease and the type of fish you are raising.

Sporozoans are a large class of pathogenic protozoa with many species. There are quite a few sporozoans related to fish diseases. They can parasitize the mesentery, gills, brain, spinal cord, and internal organs. Iodophor is the main pathogenic organism of carp. Generally, prevention and control are the main measures, otherwise it will be too late if the fish are infected.

Prevention and treatment methods:

1. Thoroughly clean the pond with quicklime, etc. to inhibit the massive reproduction of spores and reduce the occurrence of this disease;

2. Before stocking fish, add 500 grams of potassium permanganate to 1 cubic meter of water, stir to fully dissolve it to form a solution with a concentration of 500 mg/L, and soak the fish for 30 minutes. Alternatively, add 500 grams of lime nitrogen to 1 cubic meter of water, stir it thoroughly to form a suspension, and soak the fish for 30 minutes.

Myxosporidiosis Treatment

The disease is caused by myxosporeans parasitizing the skin, gills, intestines and nervous system of fish. The fish disease site has cysts, which are grayish white dots and tumors. Common myxosporeans include pancake-shaped iodine spores, wild carp sulfonium spores, crucian carp iodine spores, silver carp iodine spores, etc. Symptoms: The sick fish are emaciated, the body color is black, and they swim alone or restlessly and wildly. From October to February of the following year, it is extremely harmful to fish species. Treatment methods: 1. Sprinkle 1 jin of 90% crystal trichlorfon in the whole pond of a pond with a depth of 1 mu, and sprinkle it again after an interval of 3 to 4 days. 2. Mix 75 grams of edible sulfur powder with feed for every 10,000 fish species or 100 jin of fish, and feed it for one week. 3. Add 10 grams of 90% crystal trichlorfon to each jin of feed to feed fish, which can cure myxosporeans parasitic in the intestine. This method is also effective for ringworm disease.

Compare the following information and it is best to consult an expert for specific practices.

Other categories

1. Madness is also known as silver carp madness, mad knife, and silver carp iodine vesicle disease. It is caused by silver carp iodine vesicles parasitizing various organs and tissues of silver carp, especially the nervous system and sensory organs, such as the brain, spinal cord, paralymphatic fluid in the cranial cavity, nerves, olfactory system, balance, and auditory systems. Silver carp fry can be infected as soon as they emerge from the membrane. At present, it mainly harms silver carp of full age in production. When the disease is serious, it can cause a large number of sick fish to die; the meat of sick fish is not fresh and has a strong fishy smell, and is very thin, so the commercial value of surviving fish is also seriously affected. This disease occurs in rivers, lakes, reservoirs, and ponds across the country, especially in Hangzhou, Zhejiang.

When seriously infected, the sick fish are extremely emaciated, with a large head and a small tail, with the tail tilted upward. The weight is only about half of that of healthy fish. The length of the head is 2.95 times the height of the tail peduncle (2.2-2.3 times for healthy fish), and the body color is dull and lusterless. The sick fish swim alone in the water, often jumping out of the water and diving back into the water, repeating this many times and dying. When dying, the head often burrows into the mud. Some swim sideways and die due to loss of balance and feeding ability, so it is called crazy disease. When the fish body is dissected, white cysts of varying sizes visible to the naked eye can be seen at the place where the silver carp iodine bubble worms parasitize. The liver and spleen are atrophied, there is ascites in the abdominal cavity, and the vagus lobe of the cerebellum is significantly congested. The sick fish are severely anemic.

2. Pancake-shaped iodine blister disease is a serious fish disease during the grass carp breeding period. It is caused by the parasitism of pancake-shaped iodine blister, which mainly parasitizes the intestinal wall of grass carp, especially the lamina propria and submucosa of the foregut. It occurs in all fish farming areas across the country, with Fujian, Guangdong, Guangxi, Hunan, Hubei and other places being the most serious. The mortality rate can be as high as over 90%. The fry are infected 12 days after being put into the pond, causing a large number of deaths. When the water temperature is 27-30℃, it takes 12-15 days for the worm to develop a generation in the body of grass carp. When spores aged for 6-8 months are used to artificially infect grass carp fry, 100% of them will get sick. It mainly harms grass carp with a total length of less than 5 cm, and bighead carp, silver carp and black carp co-cultured in the same pond are not affected. The disease is prevalent from May to July, especially from May to June.

Many small white cysts are formed in the place where the pancake-shaped iodine bubble worm parasitizes, and the cysts are surrounded by connective tissue membranes formed by the host. The body color of the diseased fish is black; it is emaciated, the abdomen is slightly swollen, the gills are light red, anemia, there is no food in the intestine, the foregut is thickened, and the intestinal wall tissue undergoes degeneration and necrosis; when a large number of pancake-shaped iodine bubble worms parasitize on the spine, it can cause the fish body to bend.

According to reports from Sichuan Province, the pancake-shaped iodine bubble worm parasitizes in the muscles of carp fry, forming white cysts. The body surface of the diseased fish is uneven, and they grow slowly. When the disease is serious, it causes a large number of deaths.

3. Wild carp iodine cyst disease Wild carp iodine cyst disease parasitizes on the skin and gills of dace fry and summer fish, forming many gray-white tumor-like or dot-like cysts, especially on the body surface. In severe cases, it affects the breathing, swimming and feeding of the diseased fish, and finally causes exhaustion and death. The disease mainly occurs in Guangdong, Guangxi and other places.

Wild carp iodine bubble parasites on the gill arches and gills of carp, forming a large number of gray-white tumor-like cysts, which are formed by the fusion of many small cysts. The cysts are surrounded by connective tissue membranes formed by the host, and in severe cases can cause the death of sick fish. This disease occurs all over the country.

4. Carp iodine cyst disease Carp iodine cyst disease is a disease caused by carp iodine cyst disease and Cumulus iodine cyst disease that parasitize the muscles behind the head and back of the silver carp, causing tumor-like protrusions. This disease is more common in ponds, lakes, and rivers in Shanghai, Jiangsu, Zhejiang, and Northeast China. The incidence rate in some areas can be as high as 40%. Although it generally does not cause a large number of deaths of sick fish, it is easy to die in the absence of oxygen. At the same time, even if the sick fish do not die, they lose their commercial value due to their ugliness, and the loss is also very large. After the iodine cyst invades the skeletal muscle of the silver carp, it reproduces in large numbers. Only the capsule of the iodine cyst itself forms microcysts that are invisible to the naked eye. The host does not form any cyst wall to surround it. When the iodine cyst matures, it is scattered in the muscle fibers. Most of the iodine cysts invade, reproduce, and replace muscle fibers from the outside of the muscle fibers; a few drill into the muscle fibers to reproduce, and gradually replace the muscle fibers from the middle of the muscle fibers to the outside. Iodine bubble worms reproduce wherever they drill into the muscles behind the head of silver crucian carp, so muscle fibers and iodine bubble worms are mixed, and only the muscle fibers in the middle of the tumor-like protrusions are completely replaced by iodine bubble worms; at the same time, the iodine bubble worms do not drill into the back of the fish's dorsal fin and the abdominal muscles to form tumor-like protrusions. When the tumor-like protrusion is large, the affected area is very soft to the touch, as if it is about to burst; the tumor-like protrusion can protrude 0.5 cm from the parietal bone forward, 2.1 cm higher than the parietal bone, and reach the base of the fourth fin ray of the dorsal fin at the back and the lateral line at the bottom.

5. Round iodine cyst disease Round iodine cyst disease parasitizes on the head, gill arches and fins of carp and crucian carp, forming many cysts visible to the naked eye. These cysts are surrounded by connective tissue membranes formed by the host, and these large cysts visible to the naked eye are formed by the fusion of multiple small cysts. The disease occurs in ponds, lakes, rivers and reservoirs across the country. Although it generally does not cause a large number of deaths of sick fish, when it is severely infected, there are hundreds of large cysts visible to the naked eye on the body of a sick fish, which makes the sick fish extremely ugly and loses its commercial value.

6. Heteromorphic cyst disease Heteromorphic cyst disease parasitizes on the gills of bighead carp and silver carp, forming many white cysts the size of a needle. In severe cases, the diseased fish swim alone, the fish body is thin, the back is like a knife blade, the body surface loses its luster, the sides of the gill cover are often congested, the gill filaments are purple-red, the mucus increases, the diseased fish has difficulty breathing, and it is easy to die when the dissolved oxygen in the water is low. It mainly harms fish fry and fish species, and occurs in the Yangtze River Basin and southern provinces and cities.

7. Cercosporidiasis Cercospora dogri parasites on the gill filaments and gill arches of mandarin fish, forming large white cysts. The large cysts are formed by the fusion of multiple small cysts, and the walls at the fusion point undergo cellulose-like changes and eventually disappear; the cysts are surrounded by connective tissue membranes formed by the host, which are mainly collagen fibers, with a small number of fibroblasts and capillaries; the outside of the large cysts are also covered with hyperplastic epithelial cells and mucus cells of the host. When the spores mature, the walls of the large cysts also undergo cellulose-like changes, the cysts rupture, the spores are released, and finally the entire large cyst disappears. Only when there is a large number of parasites will it cause the death of diseased fish, especially when there is a lack of oxygen in the water.

The main hazard to the black snakehead is the Chinese cercariae, which mainly harms the summer flower fish species. In severe cases, it can cause the death of a large number of diseased fish. It occurs all over the country, especially in southern China and the Yangtze River Basin. Cercariae can parasitize in various organs and tissues of the black snakehead, mainly invading the skin and fins, forming pale yellow cysts with no fixed shape.

Toad catfish often suffers from cercosporidia during the seedling rearing stage, which forms many oval cysts on the skin, gills and fins, and can cause the death of the diseased fish in severe cases.

8. Silver carp spiral worm disease Silver carp spiral worm parasitizes the muscles, gill covers, orbital periphery, skin, fin base and kidneys of silver carp, forming yellowish granular cysts of varying sizes. In severe cases, the cysts may connect into one piece. The diseased fish are thin and weak, 1/4-1/3 lighter than healthy fish, and sometimes their eyeballs protrude. The diseased fish die slowly, and the fish that do not die also lose their commercial value due to their ugliness. It is mainly prevalent in the Linghu area of ​​Zhejiang Province.

9. Myxozoan disease, also known as vertigo, spinning disease, and dizziness, is one of the targets of port fish quarantine. It mainly harms salmonids such as rainbow trout, Atlantic salmon, and grayling. The main infection period is within a few weeks after the fish start to eat. It is one of the main diseases in the seedling stage and can cause a large number of deaths of sick fish. Although this pathogen has been found in my country, no case reports have been found.

The brain sticky body parasitizes in the cartilage tissue of the fish's skull and spine, destroying the auditory balance organ and sympathetic nerves, causing the fish to chase its own tail and rotate. The tail turns black, and the fish becomes extremely emaciated and dies. As the surviving fish grow, the black color gradually disappears, and the rotation stops, leaving behind sequelae such as bent spine, sunken back of the eyes, and inability to close or bend the lower jaw.

10. Myxosome disease in China Myxosome disease in China parasitizes on the inner and outer walls of carp intestines, forming many milky white sesame-like cysts, which seriously affect the growth and development of carp. It occurs all over the country, especially in the Yangtze River Basin and other southern regions.

11. Myxozoa shizhenensis is also known as silver carp water drop disease. Myxozoa shizhenensis parasitizes various organs and tissues of silver carp, but mainly in the abdominal cavity, forming filamentous, flat ribbon-like, block-like, branched irregular cysts. In severe cases, the cysts account for 1/4 of the fish's body weight. The abdomen of the diseased fish is swollen, the fish body is emaciated, and the weight is only about half of that of a healthy fish. The internal organs are atrophied and the abdominal cavity is filled with water. The diseased fish loses balance and swims alone. The body color is black, there is less mucus on the body surface, and it feels rough to the touch. After the diseased fish is boiled, the fish meat becomes tasteless, so it is called water drop disease. It is prevalent in Guangdong and can cause the death of the diseased fish in severe cases.

12. Hyperplastic nephropathy is also known as bloated swim bladder disease. Chen Bisheng et al. (1991) reported that myxozoites parasitize in the kidneys, spleen, liver, swim bladder, bladder, digestive tract and other organs and tissues of various marine and freshwater fish such as steelhead trout, American trout, trout, trout, grouper, crucian carp, tuna, and sea bream, forming white cysts. It is prevalent in Guangdong, Fujian, Zhejiang, Hainan, and Northeast my country. The abdomen of the sick fish is swollen, with the abdomen facing up, floating on the water surface, losing balance; or spinning in the water, or sinking to the bottom of the net; the body color becomes lighter or darker, and the fish dies a few days after the onset of the disease. After the disease has been ill for a long time, the body surface is congested, the scales fall off, and the fins are damaged. When the abdomen of the diseased fish was opened, it was found that the swim bladder was filled with gas and extremely inflated, with an obvious network of microvessels, and the enlarged swim bladder pressed on other internal organs; the kidneys were dark brown, swollen or shrunken and hardened; the liver was brown and slightly swollen, and in severe cases, its volume was reduced; the gallbladder was round and swollen, about 2-3 times that of a healthy fish; the spleen was enlarged, twice that of a healthy fish, slightly hard and dark; and the gonads were atrophied.

13. Bipolaris disease Bipolaris parasitizes on the skin of eels, forming a large number of white cysts. Although it does not cause a large number of deaths of diseased fish, the diseased fish are ugly and lose their commercial value, resulting in great losses. Some species of bipolaris parasitize on the kidneys, gallbladders, bladders, etc. of silver carp, bighead carp, black carp, grass carp, carp, etc., but no cases have been reported.

14. Tetrapolar disease of silver carp Tetrapolar disease of silver carp parasitizes in the gallbladder of silver carp. In severe cases, it can cause the fish to lose weight, turn black, have punctate congestion around the eyes, or protrude the eyeballs. The base of the fins and the abdomen are yellow, the liver is light yellow or pale, the gallbladder is extremely large and filled with yellow or yellowish brown bile; the intestines are filled with yellow sticky substances; some sick fish have water accumulation in the body cavity. Tetrapolar disease of silver carp infects silver carp fry in June and July, and is in a metamorphosis stage in the fish body during the wintering period. The first batch of mature spores is formed in the late wintering period, and often complicated with saprolegniasis and tricholoma, causing a large number of deaths of sick fish. It is prevalent in the Northeast region.

15. Monopole dace disease Monopole dace disease parasitizes under the scales of carp, crucian carp, scattered-scale mirror carp, and carp-cruciform hybrids, forming many large yellowish cysts, each of which is formed by the fusion of multiple small cysts. The largest cyst can reach the size of a ping-pong ball. The scales at the parasitic site stand up, and the diseased fish are extremely ugly and completely lose their commercial value. It occurs in the Yangtze River Basin.

16. Jitao Monopole Disease Jitao Monopole disease parasitizes the intestinal wall of the front and mid-gut of carp and scattered-scale mirror carp, forming many irregularly shaped large cysts that protrude into the intestinal cavity, blocking the intestinal tube and making it thicker. The intestinal wall becomes thin and transparent, and the abdominal cavity accumulates water. The liver is light yellow or pale, the gonads atrophy, the abdominal cavity accumulates water, and the diseased fish becomes emaciated, anemic, and gradually starves to death. It has occurred in Hunan, Hubei, Jiangsu, Shanghai, Liaoning, Guizhou, Lanzhou and other places.