Lymphocystis

Symptoms

Spotting illness early gives the best chance of a cure, so check your fish daily at feeding time. Small white, pink or grey cauliflower-like lumps on the fins, mouth or body. The fish otherwise behaves and eats normally. If you see several of these signs together, act promptly rather than waiting.

Causes

A viral infection that flares up when fish are stressed, often after transport or in poor conditions. It is unsightly but usually harmless. In nearly every case the underlying trigger is stress, poor water quality, or the introduction of an infected fish - all of which weaken a fish's natural defences.

Treatment

There is no direct cure; it normally clears on its own over weeks to months once stress is removed and water quality is excellent. Avoid cutting the growths.

While treating, increase aeration, remove activated carbon from the filter (it absorbs medication), finish the full course even after the fish looks better, and keep the water immaculate with regular changes. Always dose for the tank's true water volume and follow the product instructions.

Prevention

Reduce stress, keep water clean and stable, and quarantine new fish. The golden rules are simple: quarantine every new fish for 2-4 weeks, never overstock or overfeed, avoid sudden temperature or chemistry swings, and do regular partial water changes. A stable, clean, low-stress aquarium prevents the large majority of disease.

FAQ

This information is general guidance, not veterinary advice. Consult an aquatic vet for serious cases.