CATDOLL : CATDOLL: How should we deal with the common disease Saprolegniasis that occurs during mandarin fish farming?

Strengthen parent fish cultivation and improve the fertilization rate of fish eggs. Choose sunny weather for breeding. Before artificial breeding, clean and disinfect the spawning pool and hatching equipment.

The use of water incubation can reduce the occurrence of water cavity mildew and disease.

Soaking in 2% to 3% salt water for 5 to 10 minutes, or in a few drops of 1% vinegar for 5 minutes, both have good effects.

If Saprolegniasis occurs during mandarin fish farming, the pond should be thoroughly cleaned to kill the dormant spores of Saprolegnia; prevent diseased fish from overwintering and add immune polysaccharides to the feed.

The fish pond should be cleaned, the entire pond should be disinfected, and the infected fish should be treated to reduce losses.

Mandarin fish is a type of fish that is only distributed in rivers and lakes in the eastern plains of China. It is also called mandarin fish, osmanthus fish, ao fish, ridge flower fish, fat mandarin fish, etc. This fish hibernates in deep water in winter and swims to shallow waters in spring. Mandarin fish is now artificially bred in many places in my country. In mandarin fish breeding, one of the more common diseases is saprolegniasis. So, what should we do if mandarin fish gets saprolegniasis? What are the ways to deal with mandarin fish saprolegniasis?

1. Pathogens and symptoms

Mandarin fish hemorrhagic septicemia is a serious disease characterized by "white gills and white liver" that occurs and spreads in farmed mandarin fish. It is also known as mandarin fish hemorrhagic septicemia, fulminant epidemic, hemorrhagic disease, and fulminant viral disease. The disease mainly harms fish eggs and early fry and is the main disease affecting the hatching rate. Since the embryonic development time of mandarin fish is longer, the egg membrane is thicker than that of ordinary farmed fish eggs. It is not easy to decompose after the membrane is removed. In addition, there are a few oil balls attached to the eggs and unfertilized eggs. Once it encounters low temperature, it is easy to be infected with water mold. It has been observed that fertilized eggs stop developing after being infected with water mold. If not diagnosed and treated in time, the mold will grow in large quantities, causing the eggs to form white fluff balls, and then the embryo will die and infect other fish eggs. In the early stage of mold infection, if diagnosed and treated in time, the embryo will continue to develop, which is relatively rare in other fish; fish injured due to careless operation during the seedling stage are also susceptible to the disease.

The common disease Saprolegniasis appeared in the process of mandarin fish breeding.

2. Hazards

Saprolegniasis can occur at any time throughout the year, harming mandarin fish fry, adult fish and fish eggs. White floccules can be observed on the body surface and abrasions of diseased fish with the naked eye. Once infected with this disease, the diseased fish swims slowly, loses appetite, and finally becomes emaciated and dies.

3. Countermeasures

(1) Strengthen broodstock breeding, improve egg quality, increase egg disease resistance and ensure higher fertilization and hatching rates.

(2) After the fish have shed their membranes and are able to swim, remove the rotten eggs and egg membranes in time.

(3) During the incubation period, sprinkle 1.5 mg/L potassium permanganate or 2% to 3% saline solution in the loop once a day.