Are My Fish Happy? 6 Behavioral Signs of Healthy Fish

Fish aren’t the biggest talkers and telling how they feel isn’t always easy.

Actually, do fish have emotions and feelings at all?

While we can’t know exactly what they feel, fish certainly have emotions. They experience fear, stress, loneliness, pain, and probably an array of other emotional states. Indeed, fish have much more primitive nervous systems than we do but they are also incredibly diverse. Some are way more complex than others.

All the same, how could you tell if your fish is happy or not? Is there a way to know for sure?

In brief, a happy fish is a healthy fish. Fish with vivid, natural colors, swim around, eat regularly, socialize (or hide, if that’s their predisposition), and exhibit no breathing issues are healthy. The right conditions guarantee that they’ll feel good and happy with their lives.

Whether they can experience happiness in the sense that humans understand it (as much as we do, really, because… what is happiness?) is another question. But as long as their needs are met, fish will live healthy lives, to the maximum of their lifespans.

Then the question becomes what the right conditions are.

Let’s break it down and see what are the behavioral habits of fish, how to tell if a fish is stressed, and how to distinguish if it’s healthy.

What Does a Fish Need — Fish Natural Behavior

Fish of all species have three basic needs:

• Food
• Appropriate water conditions
• Shelter

Food is self-explanatory — every living thing needs sustenance.

The water is the environment where fish live, and it must be tailored to the species you keep. Temperature, pH levels, water hardness, ammonia, and nitrite saturation are the chief parameters that affect the living conditions of fish and other livestock in an aquarium.

Lastly, shelter is a place where fish can hide and rest. Some species are naturally more inclined to hide, others are more outgoing. Regardless, all fish like a place to chill and sleep. It may be the leaf of a plant, a small rock, the side of a driftwood, behind a submerged filter, and so forth. The more vegetation and decoration, the better in this regard.

Beyond basic needs, reproduction is another thing that all living things have encoded in our genes. With aquarium fish, if their living conditions don’t change, this need is unlikely to arise. For the vast majority of species, you’ll have to create special conditions to make them reproduce.

Lastly, some species are perfectly happy living alone, others need company.

And that’s about it — the basic needs of fish aren’t anything outlandish and, for the most part, are easy to provide.

Now, let’s see their emotional needs.

How to Tell if a Fish Is Happy: 5 Signs of Healthy Species

Fish are happy when they are healthy. Food, places to hide, proper company, and adequate water conditions will do them a world of good. The signs of a healthy fish become fairly obvious after you keep them for a while, but here they are at a glance:

1. Vivid Colors

Healthy fish will have good colors. Good diet and water conditions contribute massively to this, but there is a caveat: the substrate. Many species can and will adjust their coloration according to the color of the substrate. Typically, they will be more saturated swimming above darker substrates and paler on whiter bottoms, like yellow sand. Regardless of the color of your aquarium substrate, as long as the fish colors don’t fluctuate, they are healthy.

2. Breathing Normally

That’s a very obvious sign of an unhealthy fish — gasping for air, irregular breath intake, sticking to the surface, and labored breathing all are worrying symptoms. They usually indicate a serious health issue, either sickness or high levels of stress. Here are a few suggestions on how to deal with such crisis situations.

3. Looking Healthy

Strongly tied to the previous two points, a happy fish looks healthy — no major color changes, no spots, no broken fins, or red gills. If you are unsure what a particular species should look like, check pictures online.

Again, if the colors of yours are paler than what you see on the Web, it may be because of different substrate color and, well, Photoshop.

4. Eating Regularly

Fish are opportunistic feeders and will eat at pretty much every opportunity. If you notice a fish doesn’t eat at a couple of feedings, then something’s probably wrong. It may not like the food on offer so try to mix things up a bit.

5. Swimming Around Naturally

Healthy, happy fish usually swim around, exploring their environment, and looking for things to nibble upon. Now, that must be caveated with the fact that certain species like kuhli loach won’t be seen very often, nor will they be wiggling around much while the light is on.

Some species are naturally more active than others. Danios look like they are constantly overdoing it on the energy drinks, while plecos are slow, meticulous explorers.

All the same, when a fish is unwell its movement patterns change.

6. Socializing and Playing

Many fish species feel best in company. Danios, guppies, gouramis, and corys, to name a few, feel safe and engaged in groups. They have social habits, interact with one another, create hierarchies, and play around.

If a particular member of the school or shoal stays isolated, doesn’t move much, or is behaving radically differently from the others, something might be wrong. While each little critter in your tank has its own personality, fish from the same species share general behavioral patterns.

For instance, most of the time danios swim close to the surface, in straight lines. For these fish, abnormal behavior would be to stay close to the bottom for an extended period of time or to glass surf like maniacs.

Corydoras, on the other hand, are bottom dwellers that rarely venture to the top, especially outside feeding time. Abnormal behavior for a cory would be to spend most of its awake time close to the surface.

Unusual behavior quickly becomes obvious once you keep a species for a few days. That’s particularly true when you have a few fish of the same species.

How to Keep Your Fish Happy

Keeping your fish happy is easy, albeit quite complex when you break it down. The most important thing is to keep the water parameters stable. Temperature is a big one here — a decent heater and thermometer go a long way toward keeping warmth stable, regardless of the room temperature.

pH is another major factor. Control it through a stable, repeatable water maintenance routine. Speaking of maintenance, it is crucial for keeping your fish healthy and happy, especially in a new tank. As the aquarium matures, the maintenance sessions usually grow less frequent but in the first 8-12 months (at least!), regular water changes are a must.

Water changes bring nitrite and ammonia levels down, promoting healthy habitat.

Essentially, the basics of fishkeeping are what keep fish happy. Many people dispute whether fish are happy in a tank. The answer is yes, as long as the tank is of the adequate size, with clean water, they have the right company, shelter, and nutrition.