Parasites will draw nutrients from the fish, resulting in slower growth of fish, emaciation, some will also cause various diseases, resulting in fish death, in recent years, large-scale outbreaks of fish parasitic diseases there are three main types: Chinese loach disease, ringworm disease, anchor head loach disease, so what symptoms will be caused by these parasitic diseases, how to prevent it?
1. Symptoms of parasitic diseases
1. Chinese gill disease: the sick fish has difficulty breathing, restlessness, and increased mucus on the gills. The gill filaments are whitish at the ends. Chinese gill female insects use large hooks to hook on the gills of the fish, and when parasitizing in large quantities, many small white maggots grow on the upper edge of the gills, so it is also known as gill maggot disease. Greater Chinese bream only parasitize grass carp, dogfish and red-eyed trout, silver carp Chinese bream only parasitizes silver carp, diseased fish in the water surface whirling or swimming wildly, tail fin exposed to the water, so also known as tail disease, sick fish body emaciation, growth obstruction and even death. Chinese bream is widely distributed, from Heilongjiang in the north to Guangdong in the south; the epidemic time is long, with April to October as the epidemic season and June to September as the peak of the epidemic.
2. Ringworm disease: the gill silk liquid of the diseased fish increases, all or part of the pale color, breathing difficulties. The gills are significantly floating, the naked eye is not easy to see the insect body, take fresh gill filament under the microscope to see live insect hook on the gill filament to do ant-like movement. The insect body destroys the gill tissue of the fish, causing the fish to die. This is a common polymorphism. It has been found all over the country. It is mainly prevalent in late spring and early summer, and is mostly harmful to silver carp and grass carp species.
3. Anchor head loach disease: the worm can parasitize the whole body of the fish, the front half of the insect body drills into the host tissue, the back half is exposed outside, when seriously infected, the fish body seems to be covered with a coat, so it is called "cloak disease". When the white carp is infected with this disease, it causes swelling and inflammation of the skin tissue, forming a pomegranate-like red jue, grass carp, carp, etc. When infected with this disease, there are often scales that are "mothed" into gaps. The sick fish are in a state of restlessness and have a decreased appetite. The disease is endemic throughout the country. Anchor pupae can breed at 12-33 degrees. Fingerlings infected with anchorhead bream can be given an immunization period of more than one year.
2. Treatment of parasitic diseases
Prevention methods; (1) Improving the environment. After winter fishing or before the arrival of the spring rainy season, quicklime disinfection, the dosage of 25-40 grams / cubic meter, then less use of medicine, can save investment. (2) After disinfection, use conventional insecticides to kill insects once, 90% crystalline dimethodium 0.7 g / cubic meter or new insecticides, the dosage according to the instructions. (3) Disinfection of the medicinal bath before releasing fish: soak with 20 g/m3 potassium permanganate for 15-20 minutes or 500 g/m3 of crystalline insects for 15 minutes. (4) Reasonable stocking. Excessive density or unreasonable collocation will make the fish activity space relatively reduced, fish secrete too much adrenaline hormones, physical strength decline, thereby increasing the chance of contamination and transmission. (5) Strengthen management, operate cautiously, avoid excessive stress response, and improve the resistance of the fish itself.
Treatment: (1) 90% crystalline dimethoates 0.7 g/m3 spilled all over the reservoir. (2) Feeding bait. 100 grams of 30 kg of bran or table feed for 4 days.
The above is the prevention and treatment of fish parasitic diseases, I hope to help everyone, thorough disinfection of the pond before the release of fish fry is an effective measure to prevent diseases and parasites, we must not be sloppy.