It is commonly recognized that aquatic fungus can infect fish and cause illness. All freshwater fish, including those that are incubating eggs, may be susceptible to fungal infection. Aspergillus species, fumigate, niger, nidulans, Alternaria tenuis, Saprolegnia ferax, Allomyces anomalus, Rhizopus sp., Saprolegnia parasitica, Achlya prolifera, and Neurospora sp. are the fungal species that cause havoc in fisheries. Penicillium sp. and Aspergillus fungal sp. are the two most prevalent fungus that cause infections.