Fin rot

Fin rot is a symptom of disease or the actual disease in fish. This is a disease which is most often observed in aquaria and aquaculture, but can also occur in natural populations.

Fin rot can be the result of a bacterial infection (Pseudomonas fluorescens, which causes a ragged rotting of the fin), or as a fungal infection (which rots the fin more evenly and is more likely to produce a white 'edge'). Sometimes, both types of infection are seen together. Infection is commonly brought on by bad water conditions, injury, poor diet, or as a secondary infection in a fish which is already stressed by other disease.

Fin rot starts at the edge of the fins, and destroys more and more tissue until it reaches the fin base. If it does reach the fin base, the fish will never be able to regenerate the lost tissue. At this point, the disease may attack the fish's body directly.

Fin rot is very common in Bettas due to poor water conditions in pet stores.

Symptoms:

• Fin edges turn black / brown
• Fins fray
• Base of fins inflamed
• Entire fin may rot away or fall off in large chunks

Ways to treat:

• Change the water
• Treat with herbal remedies like Melafix
• Use common salt
• Find out the pH and correct it

Use medication specifically for fin rot:

• Maracyn TC (for positive bacterial infections)
• Maracyn 2 (for negative bacterial infections)
• Melafix (as a preventative) *Melafix contains tea tree oil which in fact damages the labrynth organ in air-breathing fish like bettas. Melafix and bettafix are not recommended for use on bettas.

Prevention:

• Make sure the water is good quality
• Feed fresh food in small portions
• Maintain constant water temperature

External links

• Fin rot: Symptoms and Treatment at AquaDaily
• Diagnosis, prevention and treatment information at the Aquarium Wiki
• http://www.practicalfishkeeping.co.uk/pfk/pages/show_article.php?article_id=263 Practical Fishkeeping Magazine article on fin rot.