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Why Do Oscar Fish Shake? (5 Common Reasons)

Why Do Oscar Fish Shake? (5 Common Reasons)

This post is written to the author's best knowledge and is not intended to be used in place of veterinary advice. In addtion, this post may contain affiliate links. As an Amazon Associate I earn from qualifying purchases.

Oscar fish are a lot of fun to own and take care of. Many people adore caring for these fish because of their great personalities.

In some ways, they’re among the best pet fish options that you can find. Of course, you need to do your best to care for the fish to keep them in good shape.

Oscars are hardy fish that have the potential to live for a long time. Even so, things can go wrong and they might experience problems sometimes.

Have you seen your Oscar fish shaking recently? That could be a bad sign, but it could also be perfectly normal.

It all depends on the context of what is happening around the fish. Read on to learn why Oscar fish shake so that you can understand what to do to help your fish if necessary.

1 – It Could Be Related to Mating

The first thing to know is that the shaking that you’re seeing could be related to mating. Sometimes Oscars start shaking when they are going through mating rituals.

It’s common for Oscar fish to start shaking their bodies and their tails during mating. During the breeding season, it’s normal for Oscars to look for mates.

As you’d expect, Oscars will also sometimes compete with each other for the right to mate. When you have more than one male Oscar fish in the tank, there might be some fighting over who gets to mate with the female Oscar.

So mating behavior and fighting can sometimes be linked together. You’ll learn more about Oscar fish fighting later.

Try to look at what’s going on in your tank to see if the Oscar is shaking for mating purposes. If there’s only one male and one female Oscar fish in the tank, there’s a good possibility that this is what’s happening.

Even so, you don’t want to rule out the other potential causes. It’s wise to continue reading so you can have a basic understanding of all of the common situations that lead to shaking.

2 – Fighting and Being Territorial

Fighting is another common cause of shaking. It’s normal for Oscars to start shaking as a precursor to fighting.

As you might know, Oscar fish are cichlids and all cichlids are at least a bit aggressive under some circumstances. Some cichlids are incredibly aggressive.

Truly, Oscars aren’t that bad as far as aggression goes. As with most fish, they will become territorial under the right circumstances.

These fish don’t like being placed in crowded environments. They grow to be rather large and commonly reach twelve inches in length in captivity.

So it makes sense that Oscars might fight or become territorial if they’re living in overcrowded tanks. They also simply don’t like tanks that are too small.

As you’d expect, Oscars might sometimes fight each other. They will fight for mating purposes to choose which male gets to mate with the female.

They might also fight to protect their territory from other Oscars. You might want to make some changes in the tank.

Perhaps you need a larger tank for the Oscars or you might need to put fewer fish in one aquarium. Consider the situation and then take appropriate actions.

3 – Putting Your Hands in the Tank

Putting your hands in the tank will sometimes cause Oscars to shake, too. This is because Oscars will often see your hand as an intruder.

You learned above that Oscars can be territorial fish. They become territorial because they see your hand as an invading force.

Not all Oscars will become territorial when a human puts their hand in the tank, though. You can even teach Oscars to be fed by hand if you put in the effort.

When Oscars are young, you can start training them not to bite. You teach them to take food out of your hands.

Continue to do this and eventually you can even pet the fish. Many people do this because they love caring for Oscars and getting to interact with pet fish in this fashion.

It’s best to do this with juvenile Oscars, though. The Oscars will be trained properly and can keep being fed by hand once they reach maturity.

Regardless, it’s good to know that your hand can cause shaking. It’s simply a sign that putting your hand in the tank makes the Oscars feel defensive, and they might try to bite you if they haven’t been trained.

4 – Issues with Water Quality

Issues with water quality have the potential to cause Oscars to start shaking. Water quality is among the most important things to pay attention to when caring for fish.

When the water gets dirty, it’s hard to keep the fish in good health. You need to regularly test the water to keep everything where it needs to be while also doing regular tank maintenance.

There are things that can happen in the tank that might make Oscars look as if they’re shivering. For instance, the temperature of the water could dip too low.

Did your heater stop working properly? If the heater isn’t working as intended, it might cause the tank to dip well below the recommended temperature range for Oscars.

Generally, you want to keep the temperature of the water somewhere between 75 degrees Fahrenheit and 80 degrees Fahrenheit. Oscars can tolerate slightly lower temperatures than this, but they do best in rather warm water.

The temperature of the water isn’t the only thing that can cause shaking. It’s possible that the pH balance could be off, too. The pH balance is meant to stay between 6.0 and 8.0 for Oscars. The ideal pH balance is around 7.2.

Water hardness should be kept between 12 and 15 dH. It’s possible that things are way off if you’re seeing the fish shake.

Test the water immediately to see how things look. You should purchase pH balance testing kits for your tank so you can regularly check things moving forward.

Fix things and then try to maintain the tank better moving forward. There are chemicals that you can use to get the pH balance back where it needs to be.

Tank Maintenance Tips

Take care of your tank well to avoid issues with water quality. You should make sure to test the tank regularly so you can make changes if the parameters are slightly off. This ensures that things will never get too bad.

Also, you need to make sure that you’re cleaning the tank regularly. Weekly cleaning sessions should become a habit for you as a fish tank owner. It’s also important to do regular water changes so the water doesn’t get too dirty.

Each week, you should change out thirty percent of the water. Doing this should keep things in check.

Oscars are messy eaters and they can make the water dirty faster than you might expect. Water changes and thorough tank cleaning are the only way to keep the water quality where it needs to be.

Buying a good filter can help to make your job easier as well. It’ll keep the cleaning from being quite as hard as it would otherwise be.

Since Oscars need large fish tanks, it’s important to buy a powerful filter. Do this and you should have a simpler time.

5 – Could the Fish Be Sick?

Have you considered whether the fish could be sick? Sometimes illnesses will cause Oscars to start twitching in a way that looks like shaking.

They might also shiver when they have some types of diseases. There could be many different things wrong with the fish.

Some types of infections might make the fish shake from time to time. You’ll need to look at the fish and try to observe other symptoms to see what’s going on.

Diagnosing an illness isn’t always going to be simple. Shaking by itself isn’t enough to diagnose a problem.

If you need assistance, it’s wise to turn to an exotic veterinarian that works with fish. This will allow you to get the issues diagnosed as fast as possible.

You can then determine the best treatment plan for the fish so it can get back to being healthy. If you can diagnose the problem by taking note of various symptoms, you can take the best treatment steps based on what seems to be wrong with the fish.

Otherwise, it’s best to follow the treatment plan provided to you by the exotic veterinarian. This will ensure that the fish will get better and you won’t have to worry any longer.

Final Thoughts

Now you know why Oscar fish might start shaking. It could be something as simple as the fish going through mating rituals.

Often, it’ll indicate that Oscars are about to fight. These fish are known to shake when they become territorial.

You need to consider whether water parameters are to blame, though. It could be that the water is too cold or that the pH balance isn’t right for the fish.

Even illnesses and infections can cause shaking. You’ll have to determine what is wrong fast to turn things around if this is the case.

Don’t be afraid to reach out for help if you need it. You can figure this out and get your Oscars feeling better again.