Shrimp swimming at the pond surface may be a sign of disease; how do you treat it according to the cause?

    Shrimp swimming at the pond surface is very common, and can be roughly divided into six situations according to the cause:

Prevention and treatment of shrimp swimming at the pond surface

    1. Swimming caused by lack of feed: This situation can occur in the early, middle and late stages of shrimp farming. The cause is mostly insufficient feed or poor-quality feed, which makes the shrimp swim to the water surface to search for food, showing regular group swimming. If this situation occurs in the early stage, the work of cultivating basic feed should be done well or small-particle shrimp feed should be given. If it occurs in the middle and late stages, compound feed should be given in time, requiring strong attractability, good palatability and comprehensive nutrition, so as to avoid weakening the shrimp's constitution or cannibalism.

    2. Swimming caused by clear water: Failure to do a good job of fertilizing the water or mass reproduction of noctiluca and similar organisms causes excessive transparency, and the shrimp, lying on the pond bottom without a sense of security, swim at the surface, showing alarm, easy jumping and group swimming. If it is caused by failure to do a good job of fertilizing the water, the measures to take are: ① appropriately exchange the water and deepen the water level; ② splash organic fertilizer or inorganic fertilizer, etc.; ③ splash microbial preparations such as photosynthetic bacteria.

    3. Swimming caused by abnormal weather: Sudden weather changes cause abrupt changes in the physical and chemical factors of the pond water, and the shrimp are stimulated and swim at the surface. After rain, the bottom water is warm and the surface water is cool, the water body stratifies, the bottom lacks oxygen, and the shrimp swim in groups at the water surface, mostly with a certain directionality. At this time, turn on the aerator to mix the upper and lower water layers evenly, then apply 0.2ppm chlorine dioxide, and after half a day, apply zeolite powder or medical stone powder.

    4. Swimming caused by lack of oxygen: At night and in stuffy weather, the dissolved oxygen in the pond water is low, exceeding the shrimp's tolerance range, and most of the shrimp float up, swimming without direction at the pond surface, mostly swimming alone. Measures to take: ① turn on the aerator to increase oxygen; ② exchange with fresh seawater; ③ add oxygen-increasing agents and so on for emergency rescue.

    5. Swimming caused by pond bottom pollution: This is relatively common in aged shrimp ponds. Because shrimp have been farmed for many years and the silt has not been thoroughly cleared, excessive residual feed and excrement accumulate at the pond bottom. Under long-term oxygen-deficient conditions, harmful substances such as ammonia nitrogen and hydrogen sulfide are produced, and when they accumulate to a certain amount they affect the shrimp's lying hidden, thus causing swimming at the surface. This kind of swimming has no obvious regularity; there is both group swimming and scattered swimming, both at the pond surface and in the water. Measures to take: ① before releasing the seedlings, clear the silt by more than 10cm, then expose to the sun for several days; ② normally turn on the aerator to lift the residual feed and excrement from the pond bottom to the surface, so that the harmful substances are oxidized into non-toxic substances; ③ spread improvers such as zeolite powder and bentonite; ④ normally use beneficial bacteria such as photosynthetic bacteria.

    6. Swimming caused by shrimp disease: Shrimp infected with diseases such as white spot, fluorescence and gill rot can also cause swimming at the surface. In this situation, the shrimp mostly swim slowly or frantically at the water surface, mostly swimming alone rather than in groups, with no obvious reaction to alarm. This situation may be a precursor to a large-scale outbreak of shrimp disease. Close observation should be made, diseased shrimp should be carefully examined, and after diagnosis the right medicine should be applied, so as to avoid causing great harm.