Here we tell you all about these signs.
Last updated: 28. November 2021
Many symptoms show that a fish is sick. Every owner should take them seriously and not overlook them, otherwise other species in the aquarium will also be exposed to a danger. Don't forget that an aquarium is a small ecosystem in which Diseases can spread quickly if the chemical balance is disturbed. In this article you will learn how to recognize a sick fish.
The life expectancy of typical tropical fish is not very long (3-5 years), but that doesn't mean you should consider their dying or poor quality of life as normal. You as the owner are responsible for the life of the animal, so a visit to a specialist is essential if there are worrying signs. Read on to learn about the 12 symptoms of a sick fish and what to do in each case.
1. The fish does not eat more
Omnivores among tropical fish forage for food in their natural environment for much of the day. Therefore, it is usually recommended that keepers sprinkle food on the water surface every 12 hours. One of the first signs that a fish is sick is that it stops eating. Biologically this does not make sense.
In these cases, it is likely that you have overfed your fish and this has led to abdominal bloating and other problems. The golden rule is not to give the animals more food than they can consume in 2 to 3 minutes, and at most twice a day. If you overdo it, the food sinks to the bottom. Then there is a potentially fatal chemical imbalance in the water.
This general rule applies to omnivores, because large carnivorous fish can go much longer without feeding.
2. The fish swims sideways
Swimming sideways is a maladaptive behavior pattern in fish as it causes them to lose their visual radius, mobility and effectiveness in moving around the tank. Therefore, a fish that struggles to move sideways is usually sick.
This symptom is usually due to a failure of the swim bladder, the organ that allows fish to exchange gases with the environment and increase or decrease their buoyancy. Inflammation of the swim bladder tie is common in Goldfish (Carassius auratus) quite often and always requires veterinary attention.
Inflammation of the swim bladder accounts for 44% of vet visits in goldfish.
3. The fish gasps for air
This symptom indicates that the fish is not sick, but that there is a chemical problem in the aquarium. The right amount of dissolved oxygen in the water is vital to the fish in the tank. They will start to gasp for air at the water surface if the concentration of this gas is not sufficient. This can be caused by Too high temperatures, too many animals in the tank and a chemical imbalance Is caused by.
In these cases it is necessary to install an aerator. If the symptom persists, perform a preventative water change.
4. The fish is isolated
Some tropical fish, such as zebra danios, tetras or certain barbs, form shoals that can range from six fish to dozens of fish. When a specimen of these species is sick, it isolates itself and keeps away from the center of activity. It is best to put the affected fish in a quarantine tank until you find out what is wrong with it.
5. One eye of the fish is pushed outwards
The clinical picture here is called goggle-eye disease (exophthalmos). It can affect one side (one eye) or both sides (both eyes) and is caused by direct injury, a chemical imbalance in the water, and fluid buildup in the animal's body. This symptom indicates that the fish is very sick (or is being attacked by other fish in the aquarium). Therefore, the animal must be treated immediately.
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6. This sign also has a special name. Is known as abdominal dropsy. In this case, the body of the fish swells, the scales stick out and look as if they are bristly. This is very common with goldfish as they are easy to spot due to their egg shaped form.
The accumulation of fluids or substances may be due to infection, an imbalance in the fish's homeostasis due to chemical changes, or intestinal blockage. Unfortunately, protruding scales indicate that the animal does not have long to live.
7. The fish has small white spots on the body
The ciliate protozoan Ichthyophthirius multifiliis causes the disease known in aquaria as white spot disease. This pathogen is found on the skin of the infected fish and begins its cycle with the formation of a visible whitish cyst, hence the name of the disease. It is a contagious disease that spreads rapidly.
For fish that can tolerate temperature fluctuations, it is recommended to increase the water temperature to 30 ° C, because the parasite dies under these conditions and the cysts fall off. Also requires medication to be applied throughout the aquarium before the rest of the fish die from it as well.
8. The fish chafes
Another symptom that a fish is sick is that it rubs itself jerkily against objects in the aquarium, which is called rubbing. This is usually a sign that the animal is infected with a skin pathogen, z. B. With an anchor worm of the genus Lernaea. Look closely at the pet's skin and scales and see a veterinarian if the behavior persists.
Scrubbing is the only way for the fish to scratch itself.
9. The fish forms strong mucus
All fish have a thin layer of mucus that covers their body and helps them swim in the water with very little resistance. When the fish is infected with certain types of parasites, this mucus becomes thicker and the skin and eyes become cloudy. Bacterial diseases often occur as a result. The parasites have caused skin damage, so the bacteria can easily "attach" there.
10. The fish remains on the bottom of the aquarium
A surface fish that stays on the bottom of the tank is either very sick or resting. If this behavior continues, you should consult a veterinarian. Most likely your aquarium is not set up properly in terms of chemicals, or the animal is suffering from an infection.
11. The gills are discolored
This symptom, which shows that a fish is sick, is not easy to see with the naked eye. Unfortunately, it becomes very obvious when the animal has already died. The gills of a healthy animal have a strong blood supply (vascularized) and are therefore red in color.
Gill discoloration can be a sign of bleeding elsewhere in the body, parasite infestation, malnutrition, and many other things. In any case, the discoloration shows that something is wrong with the fish.
12. The fins fray
This condition is called fin rot. It is a very common disease in home aquariums and is caused by infections with bacteria or fungi, with the main suspect pathogen usually being Pseudomonas fluorescens. The infection is caused by overcrowding in the aquarium, poor water conditions or improper setup.
This condition requires treating the water with antibiotics, antifungals, or a mixture of both.
The symptoms of a sick fish are varied in nature. The first step is always to isolate the fish. After that, in almost all cases, it's best to take him to the vet. Sometimes it is necessary to treat the entire aquarium at once, as most infections in these animals are very contagious.
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