Stress in fish: signs and causes of illness

Stress can be very dangerous for fish as it can cause serious illness. We tell you all about it. Fish are very quiet pets and loved by everyone, but are we aware that they can also suffer from stress? Yes, although they are not expressive, there are a number of behaviors that we must take […]

Stress can be very dangerous for fish as it can cause serious illness. We tell you all about it.

Fish are very quiet pets and loved by everyone, but are we aware that they can also suffer from stress? Yes, although they are not expressive, there are a number of behaviors that we must take into account to determine if our fish is stressed or not. Its determination is enormously important since this stress can lead to very serious illnesses or even death, without knowing exactly the reason. It is important that we understand that there are other triggers of that sudden death but, stress generates and increases these factors and various problems to the animal.

Technically, stress is made up of a series of alterations that any living being undergoes in a state of mental or physical fatigue, caused by environments that do not comfort us or an excess of activity superior to what we are accustomed to. Fish, therefore, have their own factors that can cause them that dangerous stress.

As we said, the fish that suffer this alteration can suffer serious pathologies without, unfortunately, we realise and can even die without waiting for it. Why? Well, that stress triggers a series of factors that cause your organic system to alter, affecting your immune system severely, which weakens and causes the fish to remain defenseless against potential pathogens.

Note that the level of stress depends a lot on the species of fish since there are species that are better suited to these slopes but, if you want or have an aquarium, you should inform yourself of the propensity to stress that each type of fish has.

By this, we do not mean that by solving your stress problem, we guarantee that all aquarium fish are healthy since they are sensitive to certain factors depending on the type or race but, certainly, we reduce and guarantee a positive quality of life in many of they. Taking into account that we must take care of basic factors such as food or cleaning.

Remember that if you are looking for an online shop where you can buy anything you need for your aquarium from the comfort of your house, here at Guppy’s Aquarium Products you will find them.

They mask their diseases

It is important to understand that fish are not going to give us clear signs as another animal of any disease and that they will always try to look healthy. This is a defense mechanism that they have created with their evolution to avoid being “weak” and that they are easy prey for their predator.

They need observation time

In order to detect this alteration in fish it is necessary that an observation time of the animal be carried out to detect clear changes.

What changes when they are stressed?

They change their specific biological functions thus affecting other points of the fish and even have changes in their behavior.

What should we supervise?

The most important points to detect stress and that we must monitor are: breathing, appetite, mentoring or awareness of the fish, activity and even its colors.

Appetite problems

This is the most important observation point, if we observe that the intake of our fish is much lower, it is alarming since this can trigger serious problems derived with little mobility or problems in their scales.


Like any stressed being, under a period of alteration, the rate of respiration and the rhythm increase considerably.

Swimming activity

If you see that swimming activity has increased or decreased, it can be a clear symptom of stress.


Its scales, such as the fur or skin of any animal, can be affected by some alteration by changing its color to more muted colors and even suffering continuous falls of scales. This is very determined by the endocrine system.

What factors trigger stress?

There are very clear factors that can determine stress but, like everything else, there are some occasions when animals suffer stress for no apparent reason. This has a lot to do with the type of race.

  • Water conditions: This is one of the determining factors that can cause stress in fish. Each fish needs chemical parameters in the water, perhaps the fish in question is swimming in a water in which it feels uncomfortable. To determine this, we must read about the breed in question and check the chemical aqueous parameter of our fish tank.
  • Aquarium lighting: If the lighting of our aquarium is not suitable for its type, it can cause serious alterations and stress to the animal.
  • Aquarium decoration: This is extremely important because the decoration must provide a stable and pleasant environment for the fish so it is not just to put a lot of stones and a pirate ship, it is much more! You have to know if our fish like the environment or not and this can be seen depending on their behavior and relationship with their environment.
  • Physical space: There are species that are fine in a smaller aquarium, but there are others that need much more space to feel good and swim comfortably. Otherwise, they will feel overwhelmed and limited.
  • Compatibility between species: This is very important, not all species are compatible! You have to know the habits and behaviors of each race to know if they can congenital or not.
  • Feeding: As in any living being, this is a primary factor for stress. We must bear in mind that a well-fed fish is more likely to survive than those that do not, so we must know what we feed them, how much and when.
  • Medication: You should always medicate an aquarium or a fish under supervision and under previous diagnosis of a veterinarian since the remedy may be worse than the disease.

Remember that you can get your fish tank filter online, your wave maker and any other aquarium products here at Guppy’s Aquarium Products. Contact us today for more information about our services and anything you need to keep your aquarium in optimal conditions. We’ll be happy to help you.