The fungal infection is usually caused by the fungus Branchiomyces and Aspergillus and can cause the entire gill to rot away. Infections usually occur in stressed fish that are living in tanks with high levels of ammonia or nitrate.
The fungal infection is usually caused by the fungus Branchiomyces and Aspergillus and can cause the entire gill to rot away. Infections usually occur in stressed fish that are living in tanks with high levels of ammonia or nitrate.
Fungal infections in fish generally are considered secondary to some other factor or pathogen, a consequence of water quality problems, poor condition, trauma (rough handling or aggression), bacterial disease, or parasites. Perhaps the most familiar fungal infections are those caused by Saprolegnia and other water molds.
Saprolegniasis in fish eggs which caused by Saprolegnia is a significant problem in the culture of many freshwater and brackish water species. Fungi normally do not penetrate or infect normal, healthy fertilized eggs. Infertile eggs are very susceptible to fungal infection, however, and fungi that begin their growth on infertile eggs may rapidly spread and smother adjacent fertile eggs, preventing adequate oxygenation and gas exchange.
Aphanomyces invadans (believed to be the same species as A. invaderis and A. piscicida, or very closely related) has become recognized as the primary agent associated with epizootics of ulcerative disease in cultured and wild fish around the world.
Branchiomyces species, in particular B. sanguinis and B. demigrans and other Branchiomyces-like oomycetes, have been described in several farmed and wild species of fish.