Blue-white opacification of fin edges,
Decay and fading of tail fin,
Fraying of fins,
Opacification of the cornea (keratoleukoma, nebula),
Ragged or frayed dorsal fin,
Separation of fin rays,
White ulcers near the base of disintegrated fins
In young fish, Fin Rot begins with fraying of the pectoral and dorsal fins. In adult fish, this sequence is not observed. Disease first manifests itself as bluish-white lightening of the edges of the fins. Sometimes fish will show darkening of the cornea. Then disintegration continues: the ends of the rays will fall off, as a result the fins become shorter, but they do not split much. In fry, caudal fins fall off. This is much less common in adult fish. At this stage, the line where fin tissues split is clearly visible due to white coloration. In advanced stages, the base of the disintegrated fins begins to ulcerate. These ulcers are characteristically white because of the shining bright pus. At this point, affected fish will die. In all cases of Fin Rot, the process starts on the periphery of the fins and then spreads to their base.
This is an infectious disease. It is caused by the rod-shaped Pseudomonas bacterium. The pathogen is spread in natural reservoirs from where it is brought into the aquarium together with water, soil, plants, and live foods. Newly-bought fish which have not been quarantined and given short-term therapeutic baths before introduction into the main aquarium as well as fishing tackle and other equipment shared by several aquaria facilitate transmission of disease.
Infection is most commonly brought on by outwintering fish. Fry can also get affected in case water is changed rarely. Disease is often associated with mass mortality of juvenile fish; adult fish die much more seldom. Duration of fin regeneration will depend on the extent of the damage, age as well as aquarium conditions and the diet. Fish with fully disintegrated pectoral, anal, caudal, and dorsal fins are disposed of. Disease can be easily treated if caught in the early stages.
How to cure:
Temperature should be raised to the level optimal for the spawning period of the affected fish. Treatment is carried out either in a separate or in the main tank. For treating fish in a separate tank, Basic Violet K, Malachite green, Bicillin-5 are used. Bicillin-5 solution, Malachite green with copper sulphate, Biomycin (treatment period should last for at least 1.5—2 months), White Streptocide (treatment period is 2-3 months) are added to the main tank. In fish are treated in a separate tank, the infected main tank should be disinfected. Gravel, fishing tackle and other equipment are disinfected by boiling, plants are treated with Bicillin-5. Fin regeneration is a time-taking process. After treatment has been completed, it is recommended to observe fish closely. If there is no improvement, other medications might be used to treat the disease. Levomycetin is effective for treating Fin rot. 1 tablet per 20L of water. As far as disinfectants are concerned, Blue pus bacillus sensitive to 0.5% chloramine solution, 3% hydrogen peroxide solution, 2% phenol (carbolic acid) solution.