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Detailed Explanation of the Main Symptoms and Onset Patterns of Eel Hyperactivity Disease
Caused by Eel Coronavirus-like Virus. Main symptoms: 1) Diseased eels dart erratically up and down in the water at the pond edge, or roll and spin, or swim backwards, with occasional paroxysmal spasmodic trembling or twisting of the head, mouth open, followed by death shortly after. There are no obvious external lesions, though slight congestion or ulceration may sometimes be seen in the oral cavity, anal fin, and pectoral fin areas; necropsy may reveal swelling of the liver or kidney. 2) In the early stage of onset, a small number of eels swim irregularly at the pond edge, swimming weakly, with intermittent head twitching, spinning and rolling, or backward movement. After a few days, a large number of eels show similar symptoms, with paroxysmal trembling of the head, and after frantic swimming at the water surface they die quickly; newly dead eels are rigid with the mouth open. The body surface of diseased fish is intact, but the lower jaw shows varying degrees of ulceration or congestion. Some diseased fish have congestion or ulceration in the oral cavity, anal fin, and tail. Most diseased fish have bright red gill filaments and pale red liver, and some have swollen kidneys. In diseased eels, red blood cells, hemoglobin, and serum chloride ions are significantly elevated, while blood urea nitrogen content is significantly decreased, and serum cholinesterase is reduced. At present, because understanding of this disease is still lacking, diagnosis can only be based on the above main symptoms. It mainly occurs in European eels and African eels, with the high-temperature summer period as the peak epidemic season, hence it is also called European eel summer hyperactivity disease. From the start of onset to the peak period is about 7 days, and mass mortality occurs about 15 days after onset; the speed of spread and transmission is very fast, and it readily forms outbreaks and epidemics.
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Occurrence Patterns and Control Methods of the Potato Tuber Moth
The potato tuber moth, also known as the potato borer and the tobacco leafminer, is commonly called the "string-skin worm," "embroidery worm," and "potato maggot" by farmers. 1. Damage symptoms: The larvae cause damage mainly by boring and feeding, usually entering through the buds and broken skin of the tubers. Larvae hatched on the plant spin silk and spread with the wind, boring from the leaf surface into the leaf interior to feed and cause damage. After the damaged leaves wither and die, the larvae move to other leaves to cause damage. 2. Occurrence patterns: The potato tuber moth produces several generations a year, overwintering in various stages on mother tubers in the field and on the residual plants and fallen leaves of various hosts. Adult
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What are the activity patterns of snakes? A detailed explanation
1. What are the activity patterns of non-venomous snakes? Snakes' activities follow certain patterns. Since the distribution of snake species differs, the activity patterns of snakes also differ markedly. Taking Shandong Province as an example, the activity patterns of non-venomous snakes are roughly as follows: around mid-April (Gregorian calendar) each year, when the outside temperature slowly rises to 15-18°C, all kinds of snakes wake from hibernation and crawl one after another from their hibernation dens to the entrance of the den or to sunny spots to bask. After May, once the temperature has basically stabilized, the snakes leave their dens to move about, drink water, and seek mates to copulate. However, they are not very interested in the food provided
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Cotton-lily intercropping: a commonly used cotton field intercropping and relay cropping pattern
Cotton-lily intercropping is a cotton field intercropping pattern widely used in dryland sandy loam areas along the coast and along rivers. The two crops have little mutual influence and are mutually beneficial in fertilizer use, but note that lilies cannot be continuously cropped and must be rotated to a different crop. This intercropping pattern generally has a bed width of about 3 m, with cotton planted in wide and narrow rows, wide row spacing 140 cm, narrow row spacing 50 cm, and 4 rows of cotton per bed. In the wide cotton rows, 6 rows of lilies are planted, with row spacing 20 cm and plant spacing 20-25 cm, 5000-6000 plants per mu. Cotton is raised as seedlings and transplanted, planted separately on both sides of the bed, per mu
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Occurrence Patterns and Integrated Control Methods of Pests and Diseases in Goji Berry
Goji berry is a deciduous shrub of the genus Lycium in the Solanaceae family. Its fruit is called goji berry (Lycii Fructus), and its root bark is called Digupi (Lycii Cortex); both can be used as medicine. The tender stems and leaves are eaten as vegetables. It is distributed throughout China, mostly in the wild. The related species Lycium barbarum (Ningxia goji) is mostly cultivated; its fruit is called Xi goji or Gan goji and is used medicinally, mainly produced in Ningxia, Gansu and Inner Mongolia. Goji berry suffers from pests and diseases at every stage of growth, causing great economic losses to production. The occurrence and control methods of goji berry pests and diseases are introduced as follows: 1 Diseases 1.1 Black fruit disease (anthracnose) Main
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How to prevent and control garlic heart rot? Occurrence patterns and integrated control techniques
In recent years, the garlic industry in Pizhou City has developed rapidly, with the planting area growing from 3,333 hectares in the 1970s to 33,000 hectares in 2004, making it the largest garlic production area in the country and a national standardized high-quality garlic production demonstration county (city). However, with the expansion of garlic cultivation area and the extension of continuous cropping years, various pests and diseases have become increasingly severe, especially the damage from garlic heart rot, which has worsened year by year and seriously affects garlic yield and quality. 1 Occurrence patterns and damage symptoms ① Occurrence patterns In late February 2002
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What Are the Patterns of Estrus in Female Foxes? A Detailed Explanation
During the resting period, the vulva of a female fox is covered by pubic hair, making it hard to detect; during estrus, the pubic hair parts only because the vulva becomes swollen. The estrus period of female foxes is short, mating is relatively difficult, and the optimal timing for mating is also hard to determine; in particular, silver-black foxes have a relatively high rate of failed conception. To improve the reproduction rate, it is necessary to understand the estrus patterns of female foxes and mate or perform artificial insemination at the right time. The estrus period of female foxes can be divided into three stages: Stage one: the vulva begins to swell, the clitoris enlarges, and the female begins to show signs of attraction to males and sexual excitement; this generally lasts
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A Detailed Explanation of the Occurrence Patterns and Control Methods of the Ginger Stem Borer
The ginger stem borer (also known as the corn borer, belonging to Lepidoptera, Pyralidae) is a major pest harming ginger. It has a very mixed diet; when causing damage, the larvae bite and feed on the tender stems, then bore into the stem (with frass and insect droppings accumulating at the entry hole), blocking the transport of water and nutrients, causing the stems and leaves above the bore hole to turn yellow and wilt, and they break very easily under external force. 1. Occurrence patterns. The ginger stem borer generally occurs 3-4 generations per year in our area, and the concentrated damage period coincides exactly with the vigorous growth period of the ginger plants. The larvae move from plant to plant causing damage, and finally the mature larvae
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Occurrence Patterns and Control Methods of Jujube Witches' Broom
Jujube witches' broom is a devastating disease that should be prevented rather than cured. It is very prevalent in jujube-producing regions of China. Once a tree is infected, it rarely bears fruit the following year, and even if it does, the fruit loses its edible value; after 3~4 years the entire tree dies. I. Causes of jujube witches' broom: The main cause of jujube witches' broom is the invasion of mycoplasma-like organisms. Mycoplasma-like organisms can be spread through grafting. Under natural conditions, natural root grafting between trees can also spread the disease, and some leafhoppers are also carriers of mycoplasma-like organisms. II. Integrated control measures: 1. Select and breed disease-resistant
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Occurrence Patterns and Control Methods of Jujube Fruit Shrink Disease
I. Symptoms and Damage Jujube fruit shrink disease, also known as jujube fruit wilt disease, jujube fog wilt disease, etc., is one of the major diseases in all major jujube-growing regions of China. In jujube fruits affected by fruit shrink disease, yellow-brown irregular discolored spots first appear on the fruit shoulder or body, then the fruit skin becomes water-soaked and earthy yellow with indistinct edges, and later the fruit skin turns dark red, shrinks, and loses its luster. In the diseased area of the flesh, brown spots and earthy yellow softness appear from the outside inward. Diseased fruits taste bitter. The fruit stalk turns brown or dark brown. The entire diseased fruit is shrunken and small, and falls off before maturity.
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