Pleistophora - Neon tetra disease

Pleistophora - Neon tetra disease

1. General description

This disease is caused by spore protozoa – unicellular microsporidia. Spores as cysts penetrate into fish organism through its digestive system - consumption infected fish or invertebrates. The cyst walls start to dissolve inside the intestines and spores “are injected” into bloodstream with help of anchored flagella. The spores move with blood and they look for suitable place for next development – mostly it is muscle tissue. Numerous spores develop under the influence of successive transformations in their destinations and they form new cysts. These cysts are diffuse in tissues between cells. Infected tissues start to die and they form gray-white discolorations. These cysts again penetrate into environment (water) through the skin (cracked ulcers) or after host death. These cysts are very resistant – they can live up to 4 years without a host.

2. Type of the disease

This is a microsporidia disease (formerly classified as fungi).

3. Cause of the disease

Causes of this disease are unicellular organisms: Pleistophora hyphessobryconis.

4. Favorable circumstances for development of the disease

• weakened immune system
• fish age
• infected animal food: fish, invertebrates etc.
• bat water quality

5. Common symptoms of the disease

• separation from the herd, lonely swimming
• unnatural colours: loss of colours, darkening, loss of shine
• white streaks and discolorations on the skin – especially along the spine and below the dorsal fin
• scoliosis, uncoordinated swimming because of muscles are paralysed
• nodular cysts which deform muscles
• frayed fins – especially the caudal fin
• loss of appetite - emaciation of the body

6. Types of the treatment

This is incurable disease – a treatment is ineffective. The cyst walls are resistant to antibiotics. We need transfer potentially healthy fish to a separate aquarium and we must observe them. Possibly we may do disinfectant bath for them. We should immediately commit an act of euthanasia the fish with advanced symptoms. The general tank, the substrate, all decorative elements we must disinfect.

7. Comments about this disease

• The characidae family (especially neon tetras and other tetras), cyprinidae family (danios, barbs, gold fish) and cichlids are the most sensitive to this disease.
• Many of fish can be asymptomatic carrier of the disease.
• The disease may lead to secondary bacterial infections (cichlid bloat disease, fin rot disease).

8. Prevention

• we buy live and/or animal food only in reliable sources/shops
• we need disinfect animal food
• 2 weeks quarantine for new fishmesh scale
• we should keep properly water parameters in aquarium