Control of luminous bacteria disease of South American white shrimp seedlings

Control of luminous bacteria disease of South American white shrimp seedlings

Luminous bacteria is one of the most serious diseases in seedling production. From flea to larval shrimp, Mysis prawns and larval shrimp are the most common. It has the advantages of rapid onset and high mortality, which poses a serious threat to the seedling raising work.

Symptoms: in the early stage of the disease, the activity ability of the larvae decreased, often located in the middle and lower layers of the water, the prawns and their larvae had weak bounce, poor phototaxis, reduced or non-feeding, and the body was white, especially milky white in the head and chest. Dying or dying larvae glow in the dark, the brightness of fluorescence varies with the degree of the disease and the size of the larvae, and there is no fluorescence at the initial stage of the disease. Weak fluorescence can be seen when the larvae are in a dying state, and the fluorescence is the strongest after the larvae die, which lasts for more than ten hours, and can not be seen until the body is decomposed.

Etiology: the way of infection is unprecipitated sea water, after being brought into the seedling pond and heated, the number of Vibrio increases sharply, the deposition of feces and residual bait in the seedling pond, the content of organic matter is high, which provides good nutritional conditions for the growth and reproduction of Vibrio. Abnormal environmental conditions of seedling breeding, such as larval quality, excessive density of larvae in the lower pond, and great differences in hydrophysical and chemical factors will lead to the infection of luminous bacteria.

Treatment: 1. Sprinkle norfloxacin in the whole pool and make the water contain norfloxacin 2ppm for 3 times. 2. Sprinkle sulfamethoxazole in the whole pool to make the water contain compound sulfamethoxazole 2.5ppm for 3 times.