Shrimp ciliates in hot weather should be prevented early!

It is midsummer, which is the best time for the growth and reproduction of shrimp ciliates. Ciliates have a fixed life style, and live by ingesting organic nutrients in water, which is suitable for breeding in waters polluted by organic matter.

In fresh, organic-free water, ciliates can't get enough nutrition, their growth and reproduction are inhibited, and then they die. Shrimp is the main host of ciliates, which are adsorbed on the body surface and gills of shrimp. If the shrimp is healthy and can shell normally, the parasitic ciliates will also be removed, and the shrimp has no effect. Therefore, when the temperature is appropriate, the pool water is rich in organic nutrients and has a host, ciliates reproduce sexually and asexually. Especially after the storm, the residual organic matter at the bottom of the pool turns up, which is the best time for ciliates to grow and reproduce.

The main symptoms of ciliary disease:

At the early stage of the disease, the gills, body surface and appendages of prawns were black in appearance, the body surface was gray-black and fluffy, and the mucus on the body surface felt greasy. Under the microscope, ciliated protozoa, such as bell worms, tired branches and aggregated worms, as well as organic debris, dirt and filamentous algae can be observed. In the middle and late stage of the disease, the body surface of prawns is covered with thick attachments, and the gills are covered with sludge, resulting in increased mucus, difficulty in breathing, damage to gills, decreased physical fitness, secondary bacterial or viral infection, resulting in loss of appetite and even inability to eat, which in turn leads to a large number of deaths.

Shrimp is restless and often swims by the pool, which hinders feeding and molting and affects growth. The sick shrimp floats on the water in the morning, which is slow to respond, does not eat, does not shell, and its growth is blocked. Ciliates mainly harm the respiratory system of prawns, such as a large number of epiphytes on gills, which are more likely to suffocate and die in low dissolved oxygen.

How to judge the parasitism of ciliates to prawns?

1. water quality: the turbidity, transparency and color of water give people a hazy and not refreshing feeling, and it is uncomfortable to transfer water and fertilize water. Suspect that prawns may parasitize ciliates; Or a single water body with "few" algae is also prone to ciliates;

2. The shrimp can't be fed for the time being, and its body is rough. When the lifting platform comes out of the water, there is fluorescence on the side of the carapace, yellow feet and yellow gills, which may lead to ciliates. Please check it with a microscope as soon as possible.

3. Sporadic theft occurs in the normal molting period, usually found in the morning, but not in the afternoon. After two or three days, the theft disappeared, probably because ciliates parasitized a small amount of shrimp, which led to the failure of shrimp molting.

4. Microscopic examination: attention should be paid to microscopic examination of suspected parasitic ciliates of prawns when sampling: more samples should be taken, and shrimps with different constitutions should be caught in one sampling.

Prevention and control suggestions

1. In the process of shrimp culture, the basic cause of ciliate outbreak is the deterioration of aquaculture water quality and sediments. With the deepening of the culture process, the organic debris in the pond increased, and shrimp manure and residual bait gradually deposited at the bottom of the pond. Therefore, a substrate modifier should be used to improve the bottom, promote the decomposition of organic impurities, residual bait and feces at the bottom, improve the redox potential of the substrate, and thus destroy the growth and reproduction environment of ciliates.

2. It can regularly adapt to microbial preparations such as photosynthetic bacteria and Bacillus, promote the decomposition of organic matter in aquaculture water, and reduce the probability of ciliate outbreak.

3. Mixed culture of fish that feed on organic matter at the bottom of the pond, such as tilapia.

This article is transferred from: old shrimp farmers