-
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.
-
-
Understand the patterns of fish disease onset and avoid common pitfalls in fish disease prevention and treatment
Understand the patterns of fish disease onset and common pitfalls in fish disease prevention and treatment
-
Bradyzoite disease in sheep has a sudden onset and a short course; how do you prevent and treat abomasal hemorrhage?
Prevention and treatment methods for sudden acute bradyzoite disease in sheep with a short course and abomasal hemorrhage
-
How to Propagate Poinsettia: Propagation Methods and Precautions
Since the poinsettia's flowering period falls around New Year's Day and the Spring Festival, it is often used by people to decorate the festive atmosphere, and the fiery red of the poinsettia is also very suitable for lively holidays. Friends who like poinsettias not only grow a pot themselves, but also choose to propagate them on their own, so how exactly should poinsettias be propagated?
-
How do you cultivate the offsets from Clivia division propagation?
For Clivia propagated by division, the offsets that have just left the mother plant have relatively weak growth capacity, so careful care is needed for the offsets to survive. The editor will now introduce how the offsets of Clivia should be cared for after division.
-
Indoor Environment Setup and Cultivation Tips for Spider Plants
Spider plants are relatively easy to cultivate, which is one reason why many people can grow them on their own. If a spider plant is well cared for, not only will its leaves be lush green, but it will also bloom. So what exactly are the tips for growing spider plants indoors? And what kind of environment should be provided for indoor spider plant cultivation?
条件筛选