symptoms
external symptoms
- Black spots on the body surface
photos
Photos: CL
Red and blue Colombian with black spots on the body. In addition, the animal has a fungus on the forehead. The animal died after a few days. The fungus was gone. Instead, a spot developed on the fin and the fin split. A bacterial infection was probably present.
Photos: Bojana Zecevic
Goldfish with black spots. In addition, the fish had popping eyes, swollen gills, and rapid breathing. He pinched the fins and the fins looked frayed. Treatment with Punktol didn’t seem to help.
The animal had no appetite and just lay on the floor of the pool.
Popping eyes and frayed fins indicate a bacterial infection.
Swollen gills and rapid breathing could each have been a result of the infection, but also indicate parasites on the gills. Punktol was a very useful option against parasites. Punktol is not very suitable against a bacterial infection.
However, many of the symptoms and the black spots point to the common cause of increased ammonia levels in goldfish. These probably also led to a bacterial infection.
Photos: Daniela Reinig
Veiltails with almost the same symptoms as the goldfish above. The animals got red veins on their fins. Then the scales bristled slightly. After a while the animals became apathetic and just sat around. The animals gasped. The skin became hazy and isolated but few spots appeared. One animal got black spots, although this genus only very rarely turns black. An animal got goggle eyes.
Treatments with Esha2000, salt, Melafix and Ekolfluid from JBL initially brought a slight improvement, but didn’t help in the long term. The diseased animals died after some time.
The black spots were probably caused by increased ammonia levels. These probably also led to a bacterial infection.
Photo: Puya
3 year old goldfish with black spots.
Photos: Vanessa te Laak
Female goldfish with black spots on the scales. Shortly after fish infested with scale worms had been treated with Tremazol in the aquarium, the female goldfish shown had a velvety coating on her body. The fish were then treated with Nematol and Tremazol again. About a week later, the female first had 2 to 3 black spots, later more.
Based on history, the black spots could be metacercariae. Because the black spots went away after a very active male was given away, they could also be stress spots.
Photos: Daniel Schütz
Yellow phantom tetra with bacterial infection. First, a black spot appeared on the caudal fin, which could be seen from both sides. A few days later, a second spot became visible near the pectoral fin. Both spots now looked dark red. The fish swam slightly at an angle and gasped for air. The tetra died a few days later.
causes
Black, punctiform spots can be caused by metacercaria. These spots are usually slight bumps and do not lie completely flat at the skin level.
Red-Blue Colombians
Red-Blue Colombians can develop larger black spots as they age. The cause is unclear. They are probably black guanine scales.
rainbow fish
Dead rainbowfish can turn dappled with black spots. The spine is often twisted as well. The cause of death or a specific illness cannot be inferred from this.
goldfish
In goldfish, black spots lying flat on the skin can be harmless pigment disorders or symptoms of stress.
Goldfish can also develop black spots after skin injuries and drug treatments that attack the skin. Skin injuries can result, for example, from mechanical damage when catching, low pH values, skin worms or ichthyo. The black spots are a positive sign after injuries because they indicate the healing process.
A common cause of such skin injuries in goldfish in the aquarium is skin burns caused by high ammonia levels. The protective layer of mucus on the skin is destroyed by ammonia and the skin is attacked. Many fish don’t even get a chance to develop black spots as a sign of healing when ammonia levels are high because they die first. High ammonia levels must therefore be quickly reduced by changing the water many times.
As healing begins, the areas most affected by burns turn black or brown. In these places, the skin just looks discolored. It doesn’t look like there’s anything in or on the skin. The size of the black spots ranges from barely visible spots to completely blackening the fish. Usually these are small, black spots.
If the spots are small bumps, goldfish may have some type of skin cancer. However, this cancer is rare.
Pseudotropheus and Labidochromis
In Pseudotropheus and Labidochromis species, black spots can be caused by infestation with flagellates of Cryptobia or Trypanosoma species. Black spots or stripes are typical. The animals often rub their gill covers on the ground.