Aquarium tropical fish and fish diseases




Latin name: Saorolegniales
Other names:
Pathogen: fungus

Symptoms: Cotton wool coating, Thin white thread on the ROE, Very thin white threads perpendicular to a body, Whitish spots

Initially, disease will manifest itself as white patches of filamentous hyphae that will appear on the skin, gills, and fins, most often over ulcers or lesions. If at this moment the aquarist fails to provide adequate aquarium maintenance routine and a balanced diet as well as find and eliminate the cause of the primary infection, the fungus will spread rapidly over the entire surface of the fishs body and will be seen with the naked eye. The infection spreads across the surface of its host as a white or light-yellow cotton-like film. It consists of a mass of individual hyphae. Fungal hypahe will spread over the epidermal or gill cells, causing oxygen deficiency, followed by necrosis. In the same way hyphae affect hypoderm, muscles and sometimes visceral organs. Fish condition, water temperature, hydrochemical conditions and other factors play an important role in contraction and development of the disease. These factors also influence the duration of the disease. In advanced stages, when muscles and visceral organs are affected, fish will die. Diagnosis is based on clinical sings and microscopic examination of the funguss mycelium.

It is an infectious disease caused the mould fungus Saprolegnia. Saprolegnia filaments (hyphae) are surrounded by the membrane and filled with protoplasm which contains numerous nuclei. The fungus penetrates the epidermal or gill epithelial cells. It sometimes invades the muscles and visceral organs. Water moulds are always present in aquaria, but there are a lot of them in ponds with large amounts of decomposing organic matter such as uneaten food, dead mollusks and other water organisms. Dermatomycosis will never affect healthy, well-fed fish, maintained in optimal conditions, despite the presence of the fungus in the water. The disease is found most frequently in hatchery aquaria which contain infertile eggs, dead larvae and other organic matter the pathogen feeds on. As the fungus grows, it consumes large amounts of oxygen. This disrupts the hydrochemical regime and thus kills fish eggs as well as encourages fungal growth. The disease is prevalent in lower temperatures (below 20C (68F)) and in overcrowded aquaria with dirty water. Diagnosis is made by finding mass growths of hyphae. If not treated, the fungus affects the visceral organs and fish die. If the fungus takes advantage of sick fish, the primary cause of disease should be establish and treated.

How to cure:
In early stages, it is possible to slow down the progression of disease. To treat fish in a separate aquarium, use 5% Sodium chloride solution (for 5 minutes). Increasing water temperatures and providing strong aeration will assist the elimination of disease. To make the final diagnosis, it is necessary to establish the cause of the primary infection. If it is caused by unkempt conditions or inadequate diet, adequate aquarium maintenance routine and a balanced diet should be provided. Pay special attention to the hydrochemical and thermal regimes. If fungus growth is caused by an infectious or invasive disease, it is necessary to treat it. Dermatomycosis treatment is carried out in the main or separate tank or individually (dabs). For treatment in a separate tank, use copper sulphate solution (CuSO4*5H2O), potassium permanganate (KMnO3) at the dose of 1g per 10L of water for 30 minutes (treatment is repeated every 12 hours for 10 days), Basic Violet K (it is only effective in the early stages of disease).
Also use dabs of potassium permanganate solution at the dose of 1g per 1L of water. These are used only if the skin and gills are seriously affected when treatment both in the main and in the hospital tanks proves to be ineffective. The solution must not get in touch with the gills.

copper sulphate (CuSO4 *5H2O)
potassium permanganate (KMnO3)
Basic Violet K
Fungus Cure Aquarium Pharmaceuticals, INC.
Sera mycopur, Sera ectopur, Sera acutan
Tetra General Tonic Plus, Tetra Medica FungiStop

Do not take food from ponds where outbreaks of the disease and fishs death have occurred. The disease is best prevented by providing adequate aquarium maintenance routine and a balanced diet. Environmental management is essential: any uneaten food, dead mollusks and fish should be promptly removed from the tank.

Fish susceptible to the disease/disorder: