COMMON CATFISH DISEASES AND TREATMENT

With this post, you will notice the significance of our last post on:
https://klasicalfarm.blogspot.com/2019/02/importance-of-salting-pond-and-how-to.html

Below are some diseases we have experienced and research properly on:

                                                                                            
BROWN BLOOD DISEASE

Nitrite poisoning commonly called "brown blood" disease is an environmental condition that affects a number of fish species cultured for food today including channel catfish. 

                        Its caused by elevated levels of nitrite in the pond or culture system water.

Nitrite, a product of the breakdown of ammonia by bacteria, is a compound that can enter the circulatory system of fish through the gills. Its presence at elevated levels can cause the fish blood to take on a dark brownish color, thus the name "brown blood."

              The solution is 

using salt (NaCl) as an amendment to water. More explicitly, the chloride (Cl), which is found in common salt, is the fraction of salt that is responsible for the prevention and can affect treatment of nitrite poisoning in fish. The chloride competes with nitrite at the fish gill surface for absorption.

                                                 Prevention is far more economically desirable than trying to treat fish already stressed and dying. 

The best management practice is to use salt conservatively. It is a prudent business practice to retain as much salt as possible by retaining as much water as practical. Most effective managers monitor chloride levels at least 2-3 times per month to maintain a minimum of 60 ppm chlorides.Setting standpipe elevation to capture rainfall and reduce dilution by excessive rainfall should be a conscious goal. 

As a management task, 

pond water should be monitored for chloride levels several times each year.

If a concentration ratio of 9 to 1 of chloride to nitrite is maintained in water, many more chloride ions are absorbed than are the nitrite molecules therefore; nitrite poisoning or “brown blood” disease does not develop.


                                                                                   NOTE:

* Prevention is the key and is much less expensive than correcting an existing problem.
* Maintain a minimum of 60 ppm chlorides at all times in commercial catfish ponds.
* Always maintain at least a 9 to 1 chloride to nitrite ratio. Many use a 10:1 ratio.

For more on Brown blood disease click on the link below:
 https://agrilifecdn.tamu.edu/fisheries/files/2013/09/Nitrite-Poisoning-or-Brown-Blood-Disease-A-Preventable-Problem.pdf

  ANAEMIA DISEASE

Affected fishes are black with big head and small bodies. This is attributable to overcrowding and food shortage etc.

                                    PREVENTION AND TREATMENT

Avoid over-crowding.
Adequate feeding is advisable.

                      GILL ROT

This is caused by bacteria called flexibacter columnaries. It affects different level of catfish like fingerlings, juvenile, and the symptoms are as follows
Black gill filament covered with mud or mucus.
Gill ulcerates drip off.
Inflammation and hyperemia are visible inside the opercula.

                                PREVENTION AND TREATMENT

                                                     Table salt at a concentration of 2-2.5% for 10-15 in 20liters of water..

N/B: this medication should be applied for 4-5 days.

                         GAS BUBBLE DISEASE

This is caused by oxygen saturation in the water resulting to rapid increase in algal photosynthesis. Small bubbles accumulate on the fish, intestines, skin, and filaments causing the fishes to float.

                                      PREVENTION AND TREATMENT

The addition of fresh water and fertilization to the ponds will curtail the incidence of the oxygen super saturation and gas bubbling.

                                      WATER QUALITY DISEASE

Oxygen deficiency is a major cause of suffocation and mass mortality in pond. It occurs when the weather suddenly becomes hot, or the air temperature rises and reduces the solubility of the oxygen.

                                                PREVENTION AND TREATMENT

For earthen ponds, excess mud should be removed after each culture period.
Fish tanks should be line-washed at the rate of 225-275kg1ha after each culture period, aerators may be used to increase oxygen level.

                        CRACK HEAD DISEASE

This is the most common catfish disease in ponds. The cause of this disease is not yet understood unlike earthen ponds and natural water bodies, although adverse water quality due to over feeding is believed to be the main factor and also unbalanced nutrients in the diet of the food. 

                  A fish affected by this disease shows the following symptoms;

Distended abdomen due to septicemia and hemorrhage.
Occasional exophthalmos (pop eye).
This disease can be detected at early stages; affected fish show reddish lateral line on the skull between the two air chambers.

                    PREVENTION AND TREATMENT

Feeding should be substantially reduced and pond water should be replaced.

Generally, 

the fish recovers after few weeks after which feeding can be increased little by little.

N/B: At the final stage of the disease the skull will break laterally followed by death