Red Oscar fish – Overview, Behavior, Feeding and FAQs

The red Oscar is also known as the velvet cichlid or marble cichlid. They are species of the family of Astronotus ocellatus. The red coloration in Red Oscar is an orange-red. Although it has dark gray shading and a spot on its dorsal fin. However, it is difficult to differentiate between the female and male species, as both possess similar characteristics. But you can notice their difference during spawning, because, genital papilla appears on the female body. The Red Oscar thrives best in an aquarium of at least 70 gallons, with large rocks and deep sand bottom. You should ensure to pot any plant in the tank to the root surfaces that are covered with rocks. As they normally dig up plants.

Breeding a Red Oscar Fish is a beautiful experience that yields positive results. However, there are some complications that a novice will not likely handle well. Some of their behaviors may wear you out and make it seem like you are losing your fish. Sometimes, tiny Oscars form a tight cluster for protection, which is a normal attitude that juvenile fish display. The beauty of this species is that they are not that territorial when you compare them with other larger fish. However, they are likely to consume anything that fits their mouth.

In this article, we will delve into Red Oscar fish. This is related to their lifespan, mode of feeding, tank mates, behavior, tank size and other necessary information.

Overview of Red Oscar Fish

Red Oscar fish is a species of cichlid. They are native to Columbia, French Guiana, Peru, Ecuador, and Brazil. They are mostly present along the Amazonian basin. Although you can find them living wild in some parts of the world, like Florida. But most of them were breed on purpose to produce a variety of colors.

Many people love this type of species, as it is one of the most common breeds of Oscar fish in home aquariums. This is because, they are highly intelligent and sensitive, therefore, fun to play with. The ability to be sensitive to its environment, which is seen in Red Oscar, is unique when compared with most tropical fish.

Their tank size should be large enough for breeding; it can be between 70-100 gallons. In most cases, Red Oscar fish grows to a maximum size of 11 or 12 inches. And when you weigh them, they are mostly 3lbs. Some species of Red Oscar fish can exceed 14 inches in size, but they are not usually common. Moreover, their level of growth is usually very rapid. Most people purchase them from fish stores, where they are being sold between 1 and 2 inches as babies. Once you start feeding them regularly, after you put them in an aquarium, their growth rate may be as high as them adding an inch every month. This growth rate often occurs for the first eight months. Also, once they are 12 months old they top growing at a fast pace.

The Red Oscar thrives best at a temperature between 79 and 86 degrees Fahrenheit. Also, all rocks that you place in the tank should be clean, as the females will lay 1,000-2,000 eggs on them.


The species are not easy to identify, I.e. they are widely known as monomorphic. However, the male species grow faster than females. Also, with the help of some natural strains, you can somewhat tell the difference between their male and female. Such that, the male type has some dark blotches that appear on their dorsal fins. In most cases, Red Oscar fish usually reach maturity at the age of one, and their reproduction period continues for 9 or 10 years. Sometimes, the type of season (rainy or dry) determines the timing and frequency of spawning. In which, the occurrence of rain integrates the period of spawning.

However, the detailed reproduction of the wild species is scarcely known. When opposite pairs are in captive, the female selects and clean a flat horizontal or vertical surface, on which to lay its 1000-3000 eggs. The eggs are usually opaque when they first lay them, but they become transparent after 24hours. Moreover, like most species of cichlid, they are also known to practice brood care. They care for and guard the fry carefully, and the fry is kept in pits and covered.

Territorial behavior

Most Oscar fish are infamous for their aggressive behavior, but Red Oscar fish is quite reserved when compared to most species. Regardless, they still exhibit a trait of little aggression like other species in the same family. They mostly show this behavior when there is a trace of an invader that may likely attack their aquarium or habitat. Otherwise, they do not withstand the appearance of fish that moves towards their territory. As they fight against such and may lead to harm to both fish. It is common among Oscars to protect a territory they establish by chasing other fish from it. However, the size of the aquarium depends on the size of the fish and its level of aggressiveness. Moreover, for Red Oscar fish it can be certain that there will be little stress for whoever decides to captures and breed them.

Red Oscar Fish Food

In the wild, Red Oscar Fish captures food that is small enough to fit in their mouth. Example of such food is catfish that are sedentary (I.e. inactive) in nature, such as, Rineloricaria, Bunocephalus, and Ochmacathus species. Red Oscar catches its prey by displaying a “laying-on-side” mimicry, which is similar to Nimbochromis livingstonii and Parachromis friedrichsthalii display. This implies, they exhibit a suction mechanism in capturing their prey.

Also, Vitamin C is a requirement for Red Oscar, as they develop health problems when it is often insufficient or lacking in their meal. You should feed Red Oscar fish fly with Cyclops, especially when they are free-swimming. Generally, when they are in captivity, they feed on fish food that is suitable for large carnivorous fish. Such as worms, crayfish, insects, including, crickets, grasshoppers and flies.

Red Oscar fish are carnivores that are predaceous eaters. Also, they consume a variety of meaty foods, such as larger flake food, ocean plankton, earthworms, small fish, Cichlid pellets, bloodworms, larger flake food, and tubifex worms.

Acclimation Guide for Red Oscar Fish

For proper selection of tank mate for Red Oscar fish, you need to have an understanding of the proper measures that are adequate to acclimate your Red Oscar tank.

The reason why you should acclimate your fish tank

Firstly, the water that your fish was initially placed in a fish store, had a different PH, temperature and salinity parameters when you compare it with your aquarium. Moreover, fish are very sensitive to little change in their environment, so to ensure their successful relocation, you must follow the proper acclimation process. You should note that the acclimation process takes patience and you should try not to rush any process. Also, remember to switch off the aquarium light for at least 4hours after introducing the Red Oscar fish, to enable them to adjust well to the change in environment.

Also, quarantine your fish in a separate aquarium for at least two weeks to reduce the introduction of parasites and diseases into the new aquarium. And ensure they are feeding properly and their health is in a stable state.

There are two different methods of acclimating Oscar fish; floating method and drip method. In this article, we will discuss the floating method of acclimation, as it is easier to carry out, and mostly used for acclimating Red Oscar fish.

Floating method

• Ensure you switch off the aquarium light. Also, before opening the shipping box, ensure you dim the room light, as trauma or stress may occur as a result of sudden exposure to bright light.

• Before you open the shipping bag, float the bag in the aquarium for about 15minutes. This will allow the water in the shipping bag to be familiar with the aquarium temperature while keeping a high level of dissolved oxygen.

• After floating the bag, use a metal clip to cut and open the bag. While at this, place the top edge of the back one inch downwards to form an air pocket within the lip of the bag. This step makes the bag floats on top of the water.

• Then, add a half a cup of water from the aquarium into the shipping back. Continue this process every few minutes (3-5 minutes), until the shipping bag eventually gets full. After then, remove the shipping bag from the aquarium water and pour out half of the water.

• Float the shipping bag in the aquarium and again, begin to add a half a cup of water every 4minites until the shipping bag is full.

• Finally, let out the fish and allow it to swim into the aquarium. While at this, carefully remove the shipping bag to prevent the water from entering the aquarium water.

Important facts to note for tank requirements

• A lot of people are not patient enough during the acclimation time. Which in most cases, transmit disease into the aquarium tank. However, the total acclimation process for a purchased fish takes no longer than one hour.

• Sometimes, your new fish will appear to be dead. As, some fish appear as though they are dead, and they become active once the procedure mentioned above is duly followed.

• Avoid placing an airstone into the shipping bag. Then you are acclimating your new fish. It may eventually increase the PH of the shipping bag too suddenly and increase the risk of your new fish exposure to lethal ammonia.

• After you introduce the new fish into the aquarium, ensure to keep the light off for at least four hours.

Necessary products for an easy water change in an aquarium

• Towels, tarps, and mats – During water change; it is almost impossible to avoid spills and splashes. However, you can minimize spills by putting a towel around your aquarium. You can also use the absorbent mat that is majorly for your aquarium. This mat will help clean the floor and carpet and also dry wet surfaces during aquarium maintenance.

• Siphons – Siphon in s important equipment that you need to obtain for an aquarium water change. However, they are easy to use, by drawing water from the aquarium into a sink or bucket, using gravity. Moreover, you utilize siphons by attaching it to a faucet and using the water pressure to clean and fill aquariums. Also, you can use siphons such as Quick Vac Pro for small size aquarium.

• Bacterial Additives – During water changes and gravel cleaning, some beneficial bacteria may be lost, which may result in the aquarium being filled with cloudy water. You can use nitrifying bacteria to break down deadly nitrogenous waste material that is present in the aquarium, by maintaining biological filtration.

• Water conditioners – Whenever you are changing the water in the aquarium, endeavor to use a de-chlorinator like chlorine neutralizer, to ensure that tap water is safe for aquarium inhabitants. Moreover, it will help to neutralize dangerous chlorine and chloramine.

• Aquarium journal – It is important to keep records of your routine water changes. Also, you can use the journal to document supplements, conditioners, water parameters and aquarium test results you have obtained.

Breeding Red Oscar Fish

A lot of people have found it difficult to breed red oscar fish, as they are hard to breed when in captivity. These species are very picky when choosing a mating partner. Moreover, you can put a male and female together in a tank, and you expect them to mate.

To get breeding partners, you can purchase two breeding Red oscar together, or you buy two opposite sex when they are young. And this will allow them to create bonds and connections with each other. This may take a while, as you will have to wait for 1-2 years, for them to grow to maturity, as they become fertile.
In a natural habitat, Red Oscar is likely to breed during the rainy season.

However, when you capture them, you can signal the rainy season in their aquarium by lowering the temperature of the aquarium. Changing the aquarium water or sprinkling water on the aquarium surface frequently, so also help signal rainy season. The fish initiate the breeding process by flaring their gill and using their fins to get the attention of their mate. However, this display can be a simple fin vibration or wagging.

After the two fish mate, the female usually clean a rock surface, while they lay their eggs on top of the rock. A large female can produce as much as 3,000 opaque white eggs. After 2-3 days the egg will hatch, with both parents guarding them carefully. Moreover, the females are responsible for keeping the substrate from smothering them, and also entrust the male with chasing other fish away. After the eggs crash, ensure that you move the fry to a new habitat/aquarium with a sponge filter attached to it.

Can Tiger Oscars live with Angelfish?

Angelfish and Oscars are popular species that are kept as pets. Many people wonder if they can capture these two pets and keep them the same tank. This article is also based on research that is sole to answer some questions that pet (especially fish) owners have asked in time past. You can keep Tiger Oscars and Angelfish together, as far as you are meeting the tank requirements. Moreover, Angelfish and Tiger Oscar share similar qualities, which include, tank parameters, food, and habitat set up. Also, they reserve their aggression when they have enough space to swim around.

Why Tiger Oscar and Angelfish are compatible

• Angelfish and Tiger Oscar are compatible because most of these species are docile. That is, they are less aggressive. Sometimes, they exhibit unhealthy characters when you do not care for them properly. Since both are South American Cichlids and they mostly stick to their territories, it makes them a better combination.

• When providing appropriate measures for their tank, it is usually less stressful when you compare them with some other species, as they both require the same care and temperature. Their combination is usually interesting and beautiful. However, beginners should choose other pairs of species, rather than putting Tiger Oscar and Angelfish together. Sometimes, they get complicated, and only fish experts will be able to sort them out.

Exceptions to putting Tiger Oscar and Angelfish together

• Angelfish are a more delicate species – Angelfish cannot swim as fast as Tiger Oscar, as they have long flowing fins that easily weigh them down. Also, Angelfish has a small mouth, and have no special means of defense. Moreover, it will be more difficult for Angelfish to fight against Oscars that is twice it’s the size when fighting for food or space.

• Traits – Although both fish are docile, they still have their personality or nature. Also, their aggressiveness is more intense if you put spawning pairs together in the same tank. It is also good to make proper findings or have a better knowledge of the Oscar behavior before adding it to the tank. As some Oscars do not like seeing other fish in their territory and will kill any other species seen in the same habitat.

• Mode of Feeding – Tiger Oscars are known to be docile and reserved in nature. But they fight and get more aggressive in getting their own space and food. It is, however, important that you provide an appropriate feeding structure and adequate food that will not encourage the Tiger Oscar to fight with the Angelfish.

• Body Size and Growth Rate – In most cases, Angelfish gets up to 6 inches in length, while an Oscar can grow to 14 inches in length, and 3 pounds. This implies that Oscar’s growth rate is faster, such that, they can grow 3 times more than Angelfish. Thus, a greater chance of thriving. Moreover, as time goes on, Angelfish fins get longer and it becomes an attraction to prey on, to an aggressive Oscar.

Can Tiger Oscars live with Tiger Barbs

Tiger barbs are also known as Sumatra barbs, and they are species of fish that are native to the southeastern Asian. They are a family of Cyprinidae minnows. Tiger barbs are vigorous aquarium fish, as they are full of much energy. As a result, it is most times better, to put them in a roomy and wide aquarium environment. You should ensure that this environment is also conducive for the Tiger Barbs to swim. To answer if Tiger Oscar can live with Tiger barbs, it is advisable to cut off all species of cichlid from them, as Tiger Oscar is one. Tiger barbs are not a good risk to take when you compare them living alone and putting them together with Oscars. As stated earlier that Oscars are wide eaters, regardless, Tiger barbs are not the best match for any type of cichlid.

Adult Tiger Oscars usually grow up to 3 inches in length. When they see a big and sluggish fish around them, they display a moderate level of aggression by biting on their fins. Tiger barbs are omnivores and they can feed on blood worms, brine shrimp, zucchini, tubifex worms, and daphnia.

Can Tiger Oscars live with Flowerhorn Fish

Flowerhorn is popularly known for its aggressive and insecure behavior. An adult Flowerhorn is usually very tough. So, many people prefer to put them alone in their separate tanks. But, can Tiger Oscars live with Flowerhorn fish? Definitely, yes.

Here are some things you need to consider before putting Flowerhorn fish and Tiger Oscar together.

• Put the Oscar fish in the tank first, before introducing the Flowerhorn fish. Sometimes, Flowerhorn may threaten the Oscar and will not allow Oscars to stay in their territories or share food with them.

• Make sure that your Tiger Oscar is big enough to withstand the aggression of the Flowerfish. In case the Flowerfish is bigger than your Oscar, you should expect that Flowerfish will harm your Oscar. Also, Flowerfish possesses sharp teeth that cause pain to other fish when get bite them.

Tiger Oscar compatibility

Tiger Oscars can live with other fish that are not in the same family, that is, non-cichlid. Oscars can generally live with semi-aggressive non-cichlid but are similar in size to the Oscar in the same tank with them. However, not all Oscars are compatible with the same tank mate, as some are as small as 2 inches long, while others can grow to the size of afoot.

Red Oscar Fish FAQs

What size of aquarium should I use for my Red Oscar?

As Oscars are messy, large and territorial fish, large tanks are the most suitable habitats for them. Keeping them in a small tank will increase the chance of frequently having a water quality problem. Also, it is more advisable to get a wider or longer tank than taller ones. Caring for Red Oscars can sometimes be expensive and stressful, as they grow at a very fast rate monthly. Even though you start with a wide tank with your fish, you should still change the tank as your fish keeps growing.

What substrate will my Red Oscar need?

You can use either sand and gravel as a substrate for your Oscar, as they are a perfect choice. Both substrates have their advantage and bad area, but things that are accessible to you should greatly influence your choice. Regardless of your choice, ensure you rinse your substrate well before placing it in a tank. Although Red Oscar likes to dig their tank, a one and half inch substrate are sufficient for the tank. Moreover, sand has no spaces in between, which makes it easy to filter out. Also, gravel has spaces where uneaten foods and wastes get trapped in.

Sand also has disadvantages, such that, it easily develops anaerobic pockets. These pockets can gradually gather to form hydrogen sulfide gas. When this hydrogen sulfide gets too much, it may later poison the fish. Also, the sand has a high probability of getting sucked by the filter, which may ruin the impeller.

How do I know if my Red Oscar is male or female?

A lot of people wonder how they can differentiate between male and female Oscar, especially when the intent for purchasing them is for breeding. However, it is hard to tell the difference between Oscar’s sexes by merely looking at them.

One of the ways to go about it is by venting. Venting is an act of checking the opening in the fish belly to determine its sex. The opening closer to the head is the anus, and the other opening closer to the tail is the vent (I.e. the reproductive part). In males, both openings are almost the same size, while in females, the vent is usually larger. However, venting requires that a person is skillful at it to be able to observe the difference.

The other way to tell the sex of a Red Oscar is by watching them in their spawning process. In most cases, males possess a pointed breeding tube, while the female will have a blunt and rounded one.