What should I do if the small melon worms and wheel worms can't be killed?

Ciliates are transmitted by sacs or direct contact, and common species include oblique tubeworms, small melon worms, wheelworms, cupworms, etc. The following is a topic of common melon worms and wheel worms:

Wheelworm disease

【Pathogen】The insect body generally faces forward and rotates like a wheel. The wheelworm parasitizing the surface of the fish body is larger, and the common ones are significant wheelworm, coarse spiny wheelworm, ovoid wheelworm, oriental wheelworm, etc.;

Rotifers parasitic on fish gills, common ones are ovate wheelworms, Meixi small wheelworms and so on.

【Prevalence】 Rotifer parasitizes in the gills and body surfaces of a variety of freshwater, brackish and marine fish, and sometimes in the nostrils, bladder and ureter.

The disease is endemic in all fish farming areas of the country and can occur all year round. From May to July, the disease was most severe from fry rearing to the summer flowering stage, resulting in the death of a large number of fry and bringing great losses to fingerling production.

The water temperature suitable for the propagation of this insect is 20 ~ 28 ° C. Wheelworms that fall off the fish body can live in the water for 1 to 2 days and can directly invade the new host.

It can not only parasitize on fish bodies, but also on tadpoles and crustaceans, making it a carrier of fish rotifer disease. Infection through direct contact with fish can be transmitted with water, aquatic organisms, tools, etc.

【Symptoms】 When a small amount of parasitism occurs, there are no obvious symptoms; when there is a serious infection, it can cause an increase in mucus in the parasite, the fry and fingerlings swim slowly, and the breathing is difficult and dies.

Seriously infected with wheelworm fry, its body is extremely emaciated, dark, out of group or close to the pool edge of the slow swimming, the fry body in the wheelworm denser parts, such as fins, head, body surface appear a layer of white, in the water observation is particularly obvious, some sick fish also swam around the pool in groups, showing "running horses" symptoms.

【Diagnosis】 Due to the small size of the wheel worm, the diagnosis can be made by scraping part of the mucus or gill filament on the surface of the fish body under the microscope.

【Prevention and control method】

1) Disinfect the fish body with 8 g/m3 copper sulfate solution for 20 to 30 minutes, or soak in 1% to 2% salt solution for 2 to 5 minutes for disinfection (the specific time depends on the tolerance of the fish body).

2) The diseased fish pond was sprinkled with copper sulfate and ferrous sulfate compound (5:2) on the whole pond, so that the pool water was 0.7 g/m3.

3) Each acre of pond with 15 to 20 kg of neem branches and leaves of water (tied into small bundles), turn over every other day, every 7 to 10 days to change the fresh neem leaves and branches.

4) Use 2 to 3 kg of fresh leeks per mu of pond, add 1 kg of salt, chop the leeks and mix them into salt, rub out the juice while mixing, and sprinkle the whole pond every day for 3 days.

Small melon worm disease

【Pathogen】 Multi-seeded melon worm.

【Prevalence】 There is no strict selection of fish types and ages, and all kinds of freshwater fish are parasitic, and fish farming areas at home and abroad are generally popular.

Species of cultured fish, goldfish and Nile tilapia during the wintering period are seriously hazardous.

The water temperature of the growth and reproduction of small melon insects is generally 15 ~ 25 ° C, the water temperature is lower than 10 ° C and rises to 26 ~ 28 ° C when the development stops, larvae die above 28 ° C, so the epidemic season of this disease is more obvious, generally 3 to 5 months are the most prevalent, 6 to 7 months The disease is greatly reduced, August to October is the epidemic season, November to December in addition to the small area of water bodies, especially in addition to the indoor aquarium conditions will occur this disease, generally will not occur this disease.

【Symptoms】 Small melon worms invade the skin or gill tissue of fish, peel off the host tissue as nutrition, cause tissue hyperplasia and inflammation and produce a large amount of mucus, and cover the trunk, head, fins, gills, mouth and other places with small white spots.

In severe cases, the surface of the body seems to be covered with a white film, the scales fall off, and the fins are cracked and decayed.

When the gill tissue is parasitized in large quantities, mucus increases and the gill fragments are destroyed, affecting breathing. The sick fish are unresponsive, swim slowly to the surface of the water, and soon die.

【Diagnosis】

1) The naked eye can see that there are many small white spots on the body surface or gills, and then the initial diagnosis can be made according to the symptoms.

2) The diagnosis can be confirmed by examination with a microscope.

3) If there is no microscope, the fin strips and gills parasitic small white dots can be cut off, placed in a white porcelain dish, add a little water, and use a needle to break the white dot film, if you see a small insect body rolling lively, you can diagnose.

1) The fish pond should be completely cleared with quicklime to kill the cell sac of the small melon worm.

2) Add 125 ml of formalin solution to each cubic body of water for 30 minutes, 2 times a day, and have a certain effect.

3) The diseased fish pond can be treated with Chinese herbal medicine, that is, 1 meter per mu of water depth with 210 grams of paprika, 100 grams of dried ginger slices decoction into 25 kilograms of medicinal water, sprinkled in the whole pool, once a day, for 2 consecutive days.

4) Fish raised in the aquarium suffer from this disease, the water temperature can be raised to more than 18 ° C, and the small melon worms can fall off and die.

5) Sprinkle the whole pool with methylene blue, so that the pool water is 2 g/m3.

【Precautions】 Copper sulfate or copper sulfate and ferrous sulfate combination agent can not be used to treat small melon worms, because copper sulfate not only has no killing effect on small melon worms, but can make small melon worms form sacs and multiply in large quantities, making the condition worse.

Tip: Melon worms and sporangia sacs parasitize on the surface of the fish body as "white spots" symptoms, but through the microscope can be found: the small melon worm has a horseshoe-shaped large nucleus, and the worm body does slow rotation; and the sporangia sac has many tiny sporangia, do not move.

Source of the article: Fisheries Research Institute