Summer is a high incidence of parasites, now we focus on the wheel worm, wheel worm is one of the more popular and harmful ones in farmed fish, often causing greater economic losses, even if the later medicine is cured, it will seriously affect the growth of fish in the later stage. Let's discuss the integrated control of wheelworms.
1. What does a wheelworm look like?
The wheelworm is a type of ciliate that is only about 0.07mm in size and invisible to the naked eye and can only be seen through a microscope.
Under the microscope, the wheel worm is raised on one side and recessed on the other side, and from the side that is recessed, you can see that there is a ring of teeth arranged in a wheel shape by 18 to 30 tooth bodies, which looks like a wheel. Especially when it rolls forward, it does resemble the big wheels of a tractor in motion, so we call it the "wheel bug."
Second, what fish will the wheelworm parasitize?
The adaptability of wheel worms is particularly strong, and the four major fish such as bluefish, grass carp, silver carp and bighead carp are difficult to resist the wheel worms, even tilapia with strong vitality, few diseases and low oxygen tolerance, as well as special breeding species such as spotted forktail fish, yellow eel, loach, yellow croaker, eel and so on are also difficult to escape the "magic hand".
In all regions of the country, it occurs all year round, and the large number of deaths of sick fish can be mainly from April to July.
3. What are the manifestations of sick fish infected with wheelworms?
Rotifers generally parasitize on the surface and gills of fish, and sometimes in the nostrils, bladder, and ureters. The wheelworm parasitic on the surface of the fish slides back and forth on the surface of the fish, using its unique "wheel" - the continuous rotation of the tooth ring to wear the skin and gill tissue of the fish, and then swallow its cell detritus or parasitic blood cells for nutrition, destroy the skin and gill tissue, affect the fish's breathing and normal activities, and the parasitic number will cause a large number of deaths of diseased fish.
If a large number of wheelworms are concentrated on the top and mouth of the fish, the severely worn fish can see the symptoms of white-headed white-mouthed in the water, and the fish's mouth and gills are damaged and cause feeding difficulties, shortness of breath, and even death.
Fish whitehead white mouth
Fish with wheelworms will also have symptoms of black body and "running horses", which means that fish swim wildly around the edge of the pool, and do not disperse, like horses running wildly. There are also fish that leave the group and swim wildly. "Running horses" will cause the fish to consume a lot of physical strength and eventually lose weight, exhaustion and die.
When there are a large number of wheel worms parasitic on the tail fin of the fish, it will affect the normal swimming of the fish, and even if the fish shakes the tail vigorously, it still cannot get rid of the entanglement of the wheel worm, so the fish will show a restless state.
4. How do wheelworms spread?
Wheelworms are transmitted by direct contact with fish bodies, wheelworms that leave the fish body can swim in the water, contact with fish can occur parasitic behavior, wheelworms can be transmitted with water, animals in water or aquatic weeds or algae or microorganisms and other tools. In the case of small ponds, shallow water, poor water quality, insufficient food, over-stocking, continuous rainy weather, etc., it is very easy to have outbreaks of wheelworm disease.
Fifth, the cause of the outbreak of wheelworms and the death of fish
The main causes of fish death caused by parasites are as follows:
1, the fish's physique is poor, there is no ability to resist.
When there is a rotifer parasite, the immune system has no ability to resist, and symptoms of weakness immediately appear, followed by death. After the fish overwinter, the physical consumption is larger. Therefore, after entering the spring when the water temperature rises and the fish begin to feed, it is necessary to pay attention to strengthening the nutrition of the fish, and choose a better compound feed to feed, but pay attention to the amount of each feeding not too much. At the same time, a part of nutrition and immunomodulators can be added to the feed on a regular basis, which can restore the physique of fish quickly, greatly improve the resistance to pathogens such as external parasites, and effectively prevent the outbreak of parasitic diseases.
2, the physique of the fish is not bad, but the environment of the water body is very poor.
When the rotifer parasitizes and destroys the gills, the gills are subsequently infected with a large number of bacteria, causing secondary infectious diseases and causing death. During the wintering period, due to the less water change in the pond, the metabolic waste of various aquatic organisms accumulates in the water, and after the water temperature rises in the spring, these metabolic wastes decompose quickly and consume a large amount of dissolved oxygen in the water. When the oxygen is insufficient, a large number of toxic intermediates are produced, which greatly reduces the resistance of fish and increases the chance of contracting various diseases, including parasites.
Therefore, after entering the spring, in addition to proper water replacement, it is necessary to maintain the high dissolved oxygen and good water quality environment of the water body, and the regular use of water quality improvers and disinfectants and drugs to improve water quality can effectively promote the growth of phytoplankton and the improvement of water color and fish feeding, prevent the accumulation of metabolic waste, and effectively improve the water environment in which fish live.
Sixth, the prevention and control measures of wheel worms
In aquaculture, insecticidal drugs are generally applied for parasitic diseases, but insecticides are mostly highly toxic and highly permeable pesticides, heavy metals, etc., and the better the effect, the greater the harm. Insecticides can not be applied at will, otherwise in addition to killing some parasites, it will also bring harm to the fish, causing the fish to eat less, not to eat, slippery edges, black bodies, convulsions, etc., which will directly cause death. The use of pesticides leads to drug residues in water and fish bodies, destroying water quality and endangering food safety. It also makes the parasite resistant to insecticides, and different types of drugs need to be rotated to completely kill the parasites.
To make the farmed fish have no drug residues, in line with the requirements of green food; to solve the parasite problem, do not harm the health of the fish itself; to make the water environment not polluted, for parasites, we always adhere to the principle of "prevention first, active treatment, prudent use", you can choose natural, safe, non-toxic, non-polluting, non-irritating deworming products, to deworm instead of insecticidal, can solve the problem of car parasites, but also do not hurt fish, not bad water.
Article source: Shandong Longchang Animal Health Products Co., Ltd
Please indicate the source of the reprint