Blue Oscar fish – A Complete Guide

Blue Oscar fish is a crossbred variation of the common Oscar fish. Royal blue in color with many variations of the blue color, this fish is often referred to as “majestic” or “princely”.

The many shades of blue that line its body seem to breathe on their own when it is under water. Many have described the fish as a “glowing” fish. But something else that stands out for this fish is its amazing patterns.

Blue Oscar appearance

The blues Oscar fish pattern appears very much like a connected bunch of channels. These seeming channels are filled with bright blue lights instead of the common disjointed mesh appearance. The dark blue lining on their scales make them stand out very distinctively from their cousins. The weird thing about this fish is the fact that even amongst the blue Oscar, there are variations. The differences between these sub divisions is often in the structures that their scale patterns make. Their body scale patterns definitely make them stand out from their immediate cousins.

Blue Oscar Size

The blue Oscar population seem to grow a little smaller than the usual Oscars. The adult blue Oscar ranges between 10 inches to 12 inches at the full length. This trait is unexplained but it seems to be the case.

Like all other Oscars however, the blue Oscar needs a good amount of space to swim in order to reach its full potential size at adulthood.

Blue Oscar Lifespan

The blue Oscar fish life expectancy is subject to all the usual factors that affect any other Oscar fish. They are heavily affected by whatever sort of life their keepers afford them. Are they getting enough food? Are they getting the proper food in the right proportion? Do they have enough swimming space? What is the water temperature and toxicity level? All of these things and more my contribute to how long the Oscar fish lives.
In the wild, blue Oscar fish may live as long as 15 years. In captivity however, they may live up to eighteen.

How do I make my blue Oscar live long?

Before you make a commitment to an Oscar fish, you should take the time out to learn as much as you can about them first. You should also make the effort to provide them with a fairly good life in the form of a roomy tank, (up to 50 gallons per fish) and the right filtration. Learn as much as you can about these wonderful fish and you’ll enjoy your time with them.

Blue Oscar Behavior

Oscar fish are generally known for their aggressiveness. They can also be quite territorial. The case is not different with the blue Oscar fish. There is however an undeniably variation from fish to fish. These fish have their own personalities and they often do not necessarily come aggressive. It may also depend on a lot of factors such as whether or not they have tank mates, mating partners or if they have enough food and space to mark their own territories.

Blue Oscar Tank Size

An adult blue Oscar fish needs a good amount of space to swim and just be himself. Experts recommend a minimum of 50 gallon tank for the average adult blue Oscar. A smaller tank would just be too small and this could impede the health of the Oscar fish. It is important to note that the more the fish you keep in the tank, the bigger it should be. So you should gauge your tank based on whether or not your blue Oscar fish will be having tank mates.

Blue Oscar Food

Blue Oscars’ diet mirrors that of most other Oscars. In the wild, they survive mostly on small fish, plants, and other sea creatures. In captivity however, you can feed them a wide variety of foods. From readymade processed cichlids food to frozen foods like worms and fish. They can even eat fruits and vegetables. In fact, it is very important to include fruits and veggies in your Oscar fish’s diet so that they can get a good dose of vitamins.

What is blue Oscars favorite meal

To be honest, your blue Oscar fish will eat literally anything that will fit in its mouth. From other live fish to bread and even your fingers if you let it. This is why it is important that you are intentional with deciding what you feed to your pretty blue fish. Without the right doses of vitamins and minerals, all that fascinating blueness will fade away slowly. This is often a sign that your fish isn’t getting the right vitamins. But it could also mean that your fish is sick and in urgent need for a vet.

Blue Oscar Tank Mates

Like it was stated earlier, blue Oscar fish are really just popular Oscar fish with glowing blue scale. This is no different in terms of the right tank mates for them either. Blue Oscars have just about the same potential to be aggressive little devils as any other Oscar. The difference would be that you would have an aggressive blue devil now.

Blue Oscar fish are just as territorial as their counterparts. They are really best left alone. They don’t need to have tank mates.

Important things to note when getting tank mates

If you do decide to get them tank mates, you cant get them tank mates that are small enough to fit in their mouths because then you are really just getting them snacks. You also cant get them fish that are way bigger than them because then your blue Oscar fish would also be in danger of being mauled to death or eaten.

Perhaps the most important thing to note when getting your blue Oscar fish a tank mate however is that you can keep them in twos, but never threes. This is because two Oscars may pair off and outcast the third fish. Effectively making the lone fish a trespasser and attacking him.

Blue Oscar Tank Requirements

The average blue Oscar fish will grow as long as 15 inches in its lifetime. They usually require an aquarium tank of about 50 gallons per fish. This tank should also have strong and effective filters along with good substrate and tank decors like plants.

Blue Oscar Breeding

Oscars are generally not an easy fish to breed. There are just too many variables in a successful Oscar breeding exercise and blue Oscars are not left out. As earlier stated, blue Oscars are particularly rare because you cant even be sure when you’ll get them. If you insist on breeding Oscars however, here are the steps to follow.

Find a proven couple.

The idea is to find a mating couple that have already bred at least once. This helps you to remove the questions of whether or not they are fertile or at mating age or not. Oscars reached reproductive age at about two years old. The thing however is that you can’t tell male and female blue Oscars apart as they generally look and act exactly the same.

How to know blue Oscars sex?

The one way to find out their sexes is to look around their anus for a small cone shaped organ. This is the only difference between the species.

If you find it difficult to acquire a proven couple, your next option would be to just raise them by yourself. You could buy up to 10 Oscar fish and just raise them till they start pairing up. This will definitely take more time, but you would have an assurance of gender.
You could choose to buy only blue Oscars as this will ensure that the fry produced will have enough blue Oscars amongst them.

How to make your Oscars start breeding

You can inspire breeding in the fish by making sure that they are in optimum health and condition. The water is the right ph. and temperature, the food is enough but not excessive and the fish are in good health. You will also need to siphon the gravel. Try to keep their feed rich in vitamins. You can include fruits, vegetables and meals like frozen mealworms, crickets and even frozen fish food. It is however very important to first quarantine your live feeder fish before you feed them to your blue Oscars because you may end up introducing a disease carrying fish into your tank and fish.

Breeding behavior in blue Oscars

When your Oscar fish starts to show mating interest in each other, there are some signs that you’ll see. Here is a list of possible changes you’ll notice in their behavior that may notify you to the fact that they have started mating or are preparing to mate.

Apparent change in swimming habits:

Your blue Oscar fish may start to chase each other around the tank. Slapping their tails against each other and locking mouth together as though kissing. When you notice this, it is important to pay close attention to them because they may go from this rather harmless mating dance to a rather violent fight. They also need to be around the same size as this will prevent one from being able to inflict serious harm on the other. At this point, you may want to introduce a hiding place or some sort of spawning medium to the tank. An upturned plate will usually work just fine.

Cleaning of the mating medium;

The fish will soon start to clean and prepare the mating medium while still chasing each other round the tank. This behavior is usually the heads up that they have began to mate. The laying of eggs will usually happen about three days after this. She may lay the eggs in batches of 100s. she will most likely lay about 1000 eggs over the next couple of days.

Hatching of the fry;

the fry will usually hatch within three days of laying the eggs. The success rate will be much higher than in the wild because the variables are much more stable. Your blue Oscar parents will likely eat the unfertilized eggs to prevent fungus infection from spreading through the stock. It is important to try not to upset them at all at this time because they may eat the fry in defense.


Blue Oscar fish parents may eat their fry if they feel threatened or start to feel territorial against the new fish. It is therefore very important to move the fry away from their parents as soon as you can as this will greatly increase their chances of survival.

Blue Oscar FAQs

Do blue Oscars grow big like other Oscars?

Blue Oscars grow to about 15 inches. Some other Oscar fish species may get to about 18 inches. This however doesn’t make the blue Oscars small fish. In fact, they will probably still eat as much as other Oscars and soil their tank at the same rate too. Another thing to note is that blue Oscars also require the standard Oscar fish tank sizes of 50 gallons.

Are blue Oscars aggressive

Blue Oscars are like any other Oscars in terms of temperament. They can be very territorial it aggressive. But they can also be funny and entertaining. They may even grow to recognize their owners and feeders and even tell strangers apart. Now blue Oscars may be aggressive just like every other Oscar. Some of them have completely distinct personalities and may even be calm and friendly. They are called river dogs for good reason.

Can I keep a blue Oscar with other fish?

Yes. You can have other fish in the same tank with your Oscar so long as the tank is big enough and you have taken all the other necessary precautions. For instance, you should never keep Oscars with significantly smaller fish as the Oscar may attack and eat them.

Can blue Oscars be trained?

Blue Oscars are generally very intelligent fish. They can be trained to do simple tricks and can even come to recognize their owners and feeders. They may show affection or preference for certain members of the family and can be absolute joy to watch at feeding time. So yes.. to some extent, blue Oscar fish can be trained.

Do I need warm water for my blue Oscar fish?

Oscar fish love warmer waters. In fact, they are native to the warm waters of the Amazonian rain forests. Those water maintain a constantly warm water and most Oscar fish would not survive for long in colder waters.