Diseases in aquarium fish are very common. Aquatic inhabitants most often die due to improper care. Less commonly, hereditary diseases can occur, which in most cases are incurable. Aquarium fish turn black not only due to infections, but also due to poor water quality.
Colds in fish
It may sound strange, but aquarium fish are also prone to colds. This happens, as a rule, because the water temperature is too low. Folded fins and black spots on the gills are considered the first signs of a cold.
The only way of treatment in this case is to provide the required temperature, which should be at least 23 ° C. Please note that it is not recommended to change the water abruptly. The temperature should only be raised gradually.
In some cases, the fish turn black due to a genetic predisposition. If the behavior does not change, the appetite does not disappear, and the fish is active and mobile, then there is no reason for concern.
Branchiomycosis in fish
Branchiomycosis is a very dangerous disease for aquarium fish. An aquatic inhabitant can die in just a few days. The main symptoms of such an infection are black streaks on the body and in the head area. At the same time, the fish becomes very slow and swims upside down. Outwardly, it seems that her body is altered by the head.
A sick fish must be transplanted from your neighbors. Branchiomycosis is a contagious disease that can kill all the inhabitants of the aquarium in a short time. The optimal method of treatment is considered to be a copper sulfate solution, which is added to water in minimal dosages.
If the fish regularly overeat, then the consequence of this may be their blackening. The main sign of overfeeding is the sluggish behavior of aquatic inhabitants and swollen tummies.
Fin rot
The most common cause of black spots on aquarium fish is a disease called fin rot. The darkening of the body of the fish begins precisely from the tips of the fins and tail.
There are many reasons for fin rot. The most common of these are inadequate living conditions, too many fish in the aquarium, infrequent cleaning of the aquarium, severe water pollution.
To prevent fin rot, you must regularly monitor the condition of the aquarium. Leftover feed should never accumulate on the bottom. Otherwise, the water will become uninhabitable and will have a detrimental effect on the fish.
Other causes of blackening of fish
In rare cases, the cuticle larva can cause blackening of the fish. Infection is possible only if, for example, you have added a representative of the river habitat to your aquarium fish.
Note that in some fish, black spots appear gradually, but this is not a disease. A striking example is the sword-bearer. Young fish are lighter in color. Gradually, the body turns black and multi-colored dots appear.
