Causative agent: Uronema marinum — opportunistic marine ciliate protozoan
Uronema marinum is a marine ciliate protozoan that is primarily an opportunist, targeting stressed, injured, or immunocompromised fish in saltwater aquariums. What makes Uronema particularly dangerous is its speed — an affected fish can develop open, raw-looking sores on its body and decline to death within 48 hours. The disease is increasingly reported in Australian marine aquariums, particularly following the introduction of new fish that have been stressed during transport and acclimation. The sores typically appear as crater-like wounds on the flesh of the fish, often on the flanks, and differ from bacterial ulcers in their rapid progression and the overall systemic collapse of the fish. Because time is so critical, Australian marine hobbyists should have a hospital tank prepared at all times for emergencies. Treatment involves an immediate freshwater dip to stress the parasites, followed by formalin bath and metronidazole treatment in a hospital tank. Prevention through stress reduction and rigorous quarantine is the most reliable defence.
Symptoms
- •Open red or white sores or ulcers, often on fleshy areas of the body
- •lethargy
- •loss of colour
- •rapid progression of lesions
- •fish often found near surface or resting on substrate
- •very fast decline
Treatment
- •Metronidazole
- •chloroquine phosphate
- •freshwater dip followed by formalin bath in hospital tank
- •very fast action required
Australian Medications
- •Seachem ParaGuard
- •metronidazole via vet or aquarium supplier
Commonly Affected Fish
- •Marine fish
- •wrasses, clownfish, and small or stressed fish most susceptible
Important Notes
One of the fastest-killing marine diseases. Act within hours of noticing symptoms. Always maintain a hospital tank for marine fish.