Marine hole in the head disease is a common disease in tangs and angelfish. This disease is often referred to as Head and Lateral Line Erosion (HLLE). This disease has several contributing factors, and if caught early, can usually be successfully treated.
There are several suspected contributors to the development of this disease, but one of the most commonly described is that of a vitamin deficiency, particularly Vitamin C. Chronic stress has also been suggested as contributing to the formation of the disease, as has stray voltage within the tank. Some forms of activated carbon have been thought to cause mineral imbalance and increase the incidence of the disease.
The signs of the marine form of this disease are similar to the freshwater form and include ulcers and erosions in the skin primarily located along the lateral line and head area. These lesions may start as pinpoint holes, but then grow in size. Secondary bacterial infections may develop.
Treatment of marine hole in the head disease involves addressing all of the potential causes of the disease. Providing a vitamin supplement containing Vitamin C or providing a constant supply of fresh plants in the form of edible algae or seaweed strips is important. Make sure the diet is varied and meets the specific needs of the fish you are feeding.
Check your tank for stray voltage and properly ground your tank if any voltage is present. A hand-held volt meter can be used to measure voltage. Some recent reports have indicated that this may be a more common problem than originally expected.
Maintaining excellent water quality and preventing fluctuations in temperature will also help prevent stress, which will in turn help keep the immune system strong and functioning at the best possible level. Stress from poor water quality, overcrowding, aggression, or poor nutrition will all suppress the immune system making the fish more susceptible to all diseases or infections.
If your aquarium houses tangs or angelfish, you will want to make sure that you are aware of the signs and symptoms of marine hole in the head disease. Feed your fish an appropriate diet and make sure that edible algae, seaweed, or a suitable alternative is always present. In addition, adding a vitamin supplement to the food is a good practice. Test your tank for stray voltage periodically and make sure you have a functioning ground installed in your aquarium. Keep water quality at the highest possible standards and avoid overcrowding or aggressive fish.
By following these basic precautions and providing good husbandry, you can keep your fish free from this common and potentially devastating disease.