Symptoms or Clinical Signs of Disease in Catfish that you should know
Appearance or actions can indicate the fish is not normal. Usually the first indication that fish may be sick is a reduction in feeding activity. It is, therefore, very important that the person feeding the fish be an experienced fish culturist to detect any change in feeding behavior. Any unusual behavior or abnormal physical appearance should be a “red flag” that something is wrong and should be checked immediately.
Failure to do so could result in the loss of some or all of the fish in the pond. · Physical – external and internal. You must know what a normal fish looks like to be able to tell if abnormalities are present.
Here are some abnormalities to look for: sores discolored areas bloody spots, external and internal frayed fins popeye (exophthalmia) curved backbone swollen belly pale internal organs
· Behavior. You must know how normal fish acts. Here are some abnormal behavior patterns to look for: listless reduced or no feeding (anorexia) piping or gasping (anoxia) flashing or scratching convulsions or erratic behavior in shallow water grouping around in- or outflowing water death Stress Stress is the inability of fish to adapt to change.
There are several causes of stress: ·
Dissolved oxygen. Minimum of 4 ppm; maximum not to exceed 150 percent saturation for 4-6 hours.
· Water temperature. Minimum 33ºF (0.6ºC), maximum 120ºF (48.9ºC). Don’t exceed a rapid 10ºF (5.6ºC) increase or decrease. Temperature dependence of diseases — Each disease organism has an optimum growth temperature. Temperature dependence of host immune system Effective response is impaired by temperatures that are too high or too low. Temperature regulation of chemical toxicity ·
pH. Minimum 4.5, maximum 10.5. Also affects toxicity of natural and synthetic toxicants. Natural toxic materials, such as ammonia, increase or decrease in their toxicity to fish depending on pH of the water. In the case of ammonia, it becomes more toxic at a high pH and less toxic at a low pH. Many synthetic toxins become more or less toxic as the pH changes. Copper sulfate is more toxic at a low pH than at a high pH. · Nutrition vitamins essential amino acids excess or lack of protein, fat or carbohydrates minerals
· Improper feeding practices during low oxygen feeding prior to transport time of day · Handling rough handling holding too long in confinement ·
Chemical toxicants improper dosage used in treatment improper chemicals used in treatment improper application of chemical treatment accidental application of agricultural chemicals chemical residue in soil or feed ·
Poor water quality increase in number of disease organisms reduced ability of fish to resist infection