Control of pustulosis in cultured abalone

[etiology and prevalence] the disease is caused by Vibrio fluvialis infection, which mainly infects juvenile abalone with 3 to 5 centimeters. It occurs frequently in continuous high temperature season in summer, lasts for a long time, has a high mortality rate, and causes extremely serious economic losses.

[clinical symptoms] abalone with pustulosis can see many slightly raised white pustules on the foot muscles, which can be maintained for a period of time without rupture. When the high temperature persists in summer, the condition is aggravated, the course of disease is shortened, and the pustule is ruptured in a short time. The ruptured pustules flow out a large amount of white pus, leaving deep holes ranging from 2 to 5 millimeters, so that the foot muscles show varying degrees of ulceration. Microscopic examination revealed that the rod-shaped bacteria in the pus were moving. At this time, the abalone's adhesion ability decreased and its appetite decreased, until it fell off from the corrugated board and died of hunger.

[preventive measures] Preventive measures: both juvenile and adult abalone with ① can be infected with pustulosis, especially after adult abalone is infected with this disease, the symptoms are visible to the naked eye. In order to prevent the water body polluted by pathogenic bacteria from infecting healthy abalone, diseased abalone should be fed separately from healthy abalone. ② juvenile abalone infected with pustulosis is not easy to detect, and the mortality is high. Therefore, strong and disease-free abalone parents should be strictly selected to raise seedlings. Avoid carrying pathogens in abalone parents to reduce the chance of infection of abalone seedlings. The growth temperature range of ③ pustulosis pathogen was 15: 42 ℃, the growth rate was close to the highest level at 30 ℃, and the growth rate was nearly doubled for every 5 ℃ increase in temperature between 15 to 30 ℃. Therefore, under the condition of ensuring the growth rate of abalone, keeping the low temperature environment properly, especially in the high temperature season in summer, the mass reproduction of pathogens can be controlled to a certain extent. In order to prevent the outbreak of pustulosis in the high temperature season, ④ can use drugs to prevent pustulosis in a planned way on the eve of the high temperature season. The specific method can be as follows: 3.12 grams of sulfamethoxazole per cubic body of water, bathing for 3 hours, once a day for 3 consecutive days as a cycle, and then the next cycle every 3 to 5 days.

Treatment: during the outbreak of pustulosis, 6.25 grams of compound sulfamethoxazole per cubic body of water can be used to bathe the diseased abalone. Generally, you can take a medicine bath for 3 hours a day for 3 consecutive days as a course of treatment, and stop taking drugs for 3 to 5 days before the next course of treatment. When the condition is serious and the mortality rate is high, each course of treatment can last for 5 days. Take medicine bath once a day for 3 hours each time. 1.56 g / m3 of sulfamethoxazole combined with 6.25 g / m3 norfloxacin can also be used in the bath.