Bacterial versus Fungal: Those little white tufts -
Written by Steve Skinner
It should be noted that true fungal infections in marine aquaria are extremely rare and often misdiagnosed. Typically, what are considered fungal problems will indeed be bacterial in nature. The more common causes are wounds from poor transport, netting, fish aggression, or accidental abrasions within the aquarium.
In a healthy, low-nutrient system, these wounds will often be healed by the fish's own immune system. In the absence of proper husbandry where water conditions have become nutrient-rich, coupled with an improper diet, a small concern can quickly become a calamity. Often developing into swollen or red areas, a wound can be accompanied by small white cotton “tufts†sometimes incorrectly attributed to fungal infections. Also referred to as fin or tail rot, these are, in fact, bacterial (Cytophaga-Flavobacterium) and in milder cases no medicinal treatment is needed.
Performing proper water changes with well-aged and aerated saltwater, accompanied by a properly fortified diet, will in less severe cases be all that is needed. As with Lymphocystis and Vibriosis, the living conditions must be improved. Increasing the frequency of water changes with well-aged and aerated saltwater is the best first step. By reducing the DOC and other nutrients within the system, it will effectively starve the fungi of the needed foods that sustain their growth. More importantly with the fungi as they are incapable of manufacturing their own food supply Once these goals are accomplished, the fish’s natural immune system in most cases will be able to heal the infected area.
The next step is improving the fish’s diet and reducing obvious signs of stress. Proper nutritious foods are an incredibly important part of maintaining or improving fish health and their natural immune system. With proper nutrition, an otherwise healthy fish will be able to heal itself of more simple infections without much interference from the hobbyist. That does not mean they don’t need a little helping hand. Manufactured foods are sometimes relied upon a little too often, becoming a convenient alternative to healthier choices. Feeding foods enriched by the hobbyist is the easiest and most effective means aside from natural food sources to boosting nutritional values. Adding elements such as Selcon®, ZoeCon®, or other vitamin supplements high in HUFA’s and essential lipids; boosts the immune system much like a human taking a chelated multivitamin. Beta Glucan (if available) is also a proven and powerful anti-oxidant immune booster.
Reducing the stress of the fish within the main system is also important. Stress is not the direct causal effect but in many cases it is a strong contributor. Much like any animal, continued stress reduces the natural immune response, allowing health problems to arise. Overstocking, cramping/stunting, overfeeding, improper foods, fish aggression, poor water chemistry, and the hobbyist themselves are all contributors. In other words, keep your hands out of the tank unless it’s necessary. Only by maintaining a stress-free environment can a fish live a long and healthy captive life.
In regard to true fungal infections (Saprolegnia sp.), the resulting correction of underlying conditions is still the first best step. The same appearance from wounds, spores or water molds, if you will, are the main contributors. It can also be identified in the absence of a wound by scales standing on end surrounded by white or grey cottony tufts (not to be confused with Uronema marina).
Where the infection is quite advanced or tank mates are taking advantage of the fish’s weakened condition, it is best to place the fish in a quarantine tank where it can recuperate unhindered. Be sure to transfer the fish without the use of a net. Corralling the fish into a container will prevent further damage and possible harm to other parts of the anatomy. It is important to note that most bacterial infections in marine animals are gram negative in nature so not just any medication will do. If advanced, treatment with Maracyn II® at double the recommended dose daily for seven days is the best suggestion. Furacyn® or other nitrofurazone-based medications are also effective. Slowly reducing the salinity each day toward the 16-18 ppt range will help reduce stress in the fish and aid in keeping up the appetite, which is usually curbed by such ailments. Lowered salinity will also help in the loss of vital fluids through reduced osmotic pressure, and it will also help reduce lethargy as well.
Upon the successful treatment of the infection, it is best to keep the fish in quarantine until fully recovered. Be sure to bring the salinity back to the same as the main system much more slowly than it was lowered. Fish can tolerate drops in salinity much easier than it can be raised so be sure to increase no more than 0.001/day.
Written by Steve Skinner
It should be noted that true fungal infections in marine aquaria are extremely rare and often misdiagnosed. Typically, what are considered fungal problems will indeed be bacterial in nature. The more common causes are wounds from poor transport, netting, fish aggression, or accidental abrasions within the aquarium.
In a healthy, low-nutrient system, these wounds will often be healed by the fish's own immune system. In the absence of proper husbandry where water conditions have become nutrient-rich, coupled with an improper diet, a small concern can quickly become a calamity. Often developing into swollen or red areas, a wound can be accompanied by small white cotton “tufts†sometimes incorrectly attributed to fungal infections. Also referred to as fin or tail rot, these are, in fact, bacterial (Cytophaga-Flavobacterium) and in milder cases no medicinal treatment is needed.
Performing proper water changes with well-aged and aerated saltwater, accompanied by a properly fortified diet, will in less severe cases be all that is needed. As with Lymphocystis and Vibriosis, the living conditions must be improved. Increasing the frequency of water changes with well-aged and aerated saltwater is the best first step. By reducing the DOC and other nutrients within the system, it will effectively starve the fungi of the needed foods that sustain their growth. More importantly with the fungi as they are incapable of manufacturing their own food supply Once these goals are accomplished, the fish’s natural immune system in most cases will be able to heal the infected area.
The next step is improving the fish’s diet and reducing obvious signs of stress. Proper nutritious foods are an incredibly important part of maintaining or improving fish health and their natural immune system. With proper nutrition, an otherwise healthy fish will be able to heal itself of more simple infections without much interference from the hobbyist. That does not mean they don’t need a little helping hand. Manufactured foods are sometimes relied upon a little too often, becoming a convenient alternative to healthier choices. Feeding foods enriched by the hobbyist is the easiest and most effective means aside from natural food sources to boosting nutritional values. Adding elements such as Selcon®, ZoeCon®, or other vitamin supplements high in HUFA’s and essential lipids; boosts the immune system much like a human taking a chelated multivitamin. Beta Glucan (if available) is also a proven and powerful anti-oxidant immune booster.
Reducing the stress of the fish within the main system is also important. Stress is not the direct causal effect but in many cases it is a strong contributor. Much like any animal, continued stress reduces the natural immune response, allowing health problems to arise. Overstocking, cramping/stunting, overfeeding, improper foods, fish aggression, poor water chemistry, and the hobbyist themselves are all contributors. In other words, keep your hands out of the tank unless it’s necessary. Only by maintaining a stress-free environment can a fish live a long and healthy captive life.
In regard to true fungal infections (Saprolegnia sp.), the resulting correction of underlying conditions is still the first best step. The same appearance from wounds, spores or water molds, if you will, are the main contributors. It can also be identified in the absence of a wound by scales standing on end surrounded by white or grey cottony tufts (not to be confused with Uronema marina).
Where the infection is quite advanced or tank mates are taking advantage of the fish’s weakened condition, it is best to place the fish in a quarantine tank where it can recuperate unhindered. Be sure to transfer the fish without the use of a net. Corralling the fish into a container will prevent further damage and possible harm to other parts of the anatomy. It is important to note that most bacterial infections in marine animals are gram negative in nature so not just any medication will do. If advanced, treatment with Maracyn II® at double the recommended dose daily for seven days is the best suggestion. Furacyn® or other nitrofurazone-based medications are also effective. Slowly reducing the salinity each day toward the 16-18 ppt range will help reduce stress in the fish and aid in keeping up the appetite, which is usually curbed by such ailments. Lowered salinity will also help in the loss of vital fluids through reduced osmotic pressure, and it will also help reduce lethargy as well.
Upon the successful treatment of the infection, it is best to keep the fish in quarantine until fully recovered. Be sure to bring the salinity back to the same as the main system much more slowly than it was lowered. Fish can tolerate drops in salinity much easier than it can be raised so be sure to increase no more than 0.001/day.
