Severe

Freshwater Tropical

Columnaris

A highly contagious bacterial infection (Flavobacterium columnare) presenting as white/grey patches, often on the mouth, fins, or gills.…

Severe

Marine / Saltwater

Marine Ich (Cryptocaryon irritans)

Saltwater white-spot disease. A 2006 resistant strain renders traditional copper and formalin treatments ineffective β€” quinine sulfate is…

Severe

Freshwater Tropical

Velvet (Oodinium)

Dinoflagellate parasite producing a fine, gold-dust coating across the body. More lethal than ich; gill infection causes rapid…

Severe

Freshwater Tropical

Branchiomycosis (Gill Rot)

Fungus (true fungus) disease of aquarium fish. Key signs: rapid breathing, gasping at surface, gill necrosis with white/marbled…

Severe

Freshwater Tropical

Streptococcosis

Bacterium disease of aquarium fish. Key signs: exophthalmia (often unilateral, 'pop-eye'), corneal opacity, spinning/spiral swimming, darkening, hemorrhages around…

Severe

Freshwater Tropical

Columnaris (Cotton-Wool Disease)

Bacterium disease of aquarium fish. Key signs: white-grey saddle-shaped lesion across back, frayed fins, mouth fungus-like white patches,…

Severe

Freshwater Tropical

Enteric Redmouth Disease (ERM)

Bacterium disease of aquarium fish. Key signs: subcutaneous hemorrhages around mouth and throat (the 'red mouth'), darkening, exophthalmia,…

Severe

Freshwater Tropical

Furunculosis

Bacterium disease of aquarium fish. Key signs: acute: rapid mortality without obvious external signs; chronic: characteristic 'furuncles' β€”…

Severe