Oscar Fish
Introduction – The Big Boy.
They have many nicknames like “the big boy”, “Monster”, “the Giant”.
You can probably figure out and create an image of this fantastic fish by reading these nicknames.
With many nicknames: Big Boy, Monster, Giant. Discover Why Oscar fish are one of the most popular fish and one people often regret to have.
The Astronotus Ocellatus, popularly known as Oscar fish, is famous for being an aggressive fish despite swimming elegantly.
Also known as the velvet cichlid, these creatures can change color for many reasons.
Its colors and appearance are the initial reason why aquarists decide to have an Oscar. It is only a matter of time before they become captivated by their intelligence and behavior.
Oscar fish are temperamental creatures and are considered a fish for experienced aquarists. Despite their beauty, they are also famous for their territorial and aggressive behavior, which can make them difficult to care for.
As omnivores, they are easy to feed, but finding other fish you could keep together with them can be challenging.
My intention with this post is to explain everything you need to know about them.
If I forgot something, let me know, and I will gladly answer your question and add it to my guide. You can use my Contact Form for this.
Table of Content
Getting to Know Oscar Fish Better (about their species, from where they are, etc)
The Oscar fish (Astronotus ocellatus) is a species of cichlid. It belongs to the Cichlidae family, more precisely, to the Astronotinae subfamily.
Other cichlids are, for example, Angel Fish, Ram, Parrot cichlids, Discus, etc.
Most cichlids are found in Africa or South America. Oscar fish are native to Brazil, Ecuador, Colombia, French Guiana, and Peru.
They can be found along the Amazon River and its surroundings.
Wild populations were spotted in China and North America.
In the US, they are found in Florida’s water canals and Everglades.
Common Oscar Behaviors
Oscar fish are territorial. Adding them to your community tank can be risky.
If you are going to give your Oscar a tank mate (even if it is another Oscar or a bigger fish), make sure you are ready to monitor and control their behavior for some hours or days.
They are not afraid to attack other fish and will do so if a fish invades their territory.
Their aggression can also increase during mating and feeding times.
Sometimes, Oscars will attack their reflection, demonstrating their potential aggression to other Oscars or fish in the same aquarium.
Oscar fish usually swim in the aquarium’s middle levels, although they often swim to the substrate for food.
During this food search, you may see them tearing up decorations and plants, which is why you will see Oscars in fish tanks with just the substrate and some big rocks.
If you decide to pair your Oscars with plants, ensure you cover the roots well, as they are known to dig up plants in your aquarium.
Another attribute of Oscars is that they like to hide, so make sure to give them ample hiding places in the aquarium.
If you ever see your Oscar start changing colors, that’s not a good sign and means they feel endangered.
Lastly, it is essential to note that Oscars like to jump. Make sure that your aquarium has a tight-fitting hood.
What is good about Oscar fish?
Oscars are famous for interacting with their owners.
There are many stories of Oscars recognizing owners when they come into the room, and much like dogs, they even “wag” their tails.
Make sure you give them plenty of attention, just like you would do with a puppy!
Oscar Fish Size and Body Characteristics
Oscar fish grow a lot, reaching up to 11 inches (30 centimeters). They reach this size quickly in their lifetime, growing on average 1 inch (2 cm) per month until fully grown.
They have a long and oval body. The dorsal and anal fins extend along the body to the caudal fin, which forms a fan at the back.
You will find it difficult to sex this species as it is monomorphic, meaning both sexes look the same. You need to closely examine the genitals to differentiate them.
Classically, these cichlids are covered in a variety of irregular black and orange spots (Oscar tiger), but the colors can change over time.
Many varieties have been created through selective breeding.
Oscar red and lemon fish have bodies that are almost entirely red or yellow, respectively. Their fins tend to be black or white.
Albinos are another popular choice. There are albino varieties for many species; people are attracted to the bold white that covers the entire body.
Initially, Oscar fish were available in three colors, but due to crossbreeding, various colors, shades, spots, and patterns are now found in them, and hence, we have various types of Oscar fish.
Based on color and patterns, these are some of the most popular Oscar fish variants:
- Oscar Tiger Fish
- Tiger oscar fish
- Bronze Oscar Fish
- Bronze oscar fish
- Albino Oscar Fish (Red Tiger Albino)
How to Set Up an Aquarium for Oscar Fish?
To correctly set up an aquarium for your Oscar fish, you should design it to replicate the natural conditions where they live (read more here).
Let’s go through the main characteristics you should follow.
What is the ideal temperature for an Oscar fish?
The ideal temperature for Oscar fish is between 72°F and 82°F.
South America’s fresh water, such as the Amazon River, is warm (72-82°F), so Oscar fish cannot handle extremely low or high temperatures.
Do I need a water heater for my Oscar Fish Tank?
Although your Oscar tolerates temperatures between 68°F and 91°F (20 and 33 degrees) well, a thermostat is necessary as lower temperatures can reduce its metabolism and facilitate the emergence of diseases.
What is the ideal pH for an Oscar fish?
The ideal pH for Oscar fish is between 6.5 and 7.0.
Due to a lot of organic material, South America’s fresh water is Neutral or Slightly Acidic (from 6.5 to 7.0), so Oscar fish cannot handle extremes of Acidity or Alkalinity.
What are some of the other essential characteristics you should follow when setting up your Oscar fish tank?
Despite the water temperature and pH, these are some of the other essential characteristics you should follow when setting up your Oscar fish tank:
Water flow tends to be strong.
Although Sunlight is intense, the water is not crystal clear. Some of the light intensity is filtered out as the light penetrates the water.
Although it is not common, Oscar fish also jump out of the aquarium and die because of this, so keep the aquarium covered.
At the bottom of the river, there is a soft Substrate with Rocks, Debris, and Vegetation scattered on top.
It is relatively easy to recreate these conditions in your aquarium.
It is relatively easy to recreate these conditions in your aquarium.
What is the ideal aquarium / fish tank size for an Oscar Fish
The ideal size of an aquarium / fish tank for an Oscar fish is at least 50 US gallons (200 liters) for one fish.
A smaller tank will cause stress, making them sick or more aggressive.
What is the recommended Substrate and Rocks for your Oscar Fish aquarium.
The recommended substrate and rocks for Oscars are as follow: at the bottom of the aquarium, there must be a soft substrate bed. Softer substrates are fine-grained, so sand would be ideal (read more about how to prepare and use sand on your tank).
A more natural look would be to place rocks and driftwood around the aquarium, but you can choose any decoration.
Make some caves for each fish so they have a place to hide in their territory.
Also, remember to firmly secure decorations in place, as this species will dig around objects when looking for food and may move them.
Natural plants are unlikely to be eaten, but they are still not safe. Just like decorations, plants can be uprooted as they dig into the substrate.
Do Oscar Fish require Water Filtration?
Oscar fish produce a large amount of dirt, either through food remains or feces, so it is crucial to have good filtration.
Oscar Fish Water Parameters Chart
Characteristic | Preferred Range |
---|---|
Water pH | 6.5 – 7.5 (slightly acidic to neutral) |
Water Temperature | 74°F – 80°F (23°C – 27°C) |
Water GH (General Hardness) | 8 – 12 dGH (moderately hard) |
Water KH (Carbonate Hardness) | 6 – 10 dKH (moderately alkaline) |
Tank Size | Minimum 75 gallons (284 liters) for a single adult Oscar; larger tanks are better for multiple Oscars and growth |
What do Oscar fish eat?
Oscar fish eat almost everything that fits in their mouth, but they usually prefer proteins.
In the wild, their diet includes insects, worms, small fish, fruits that fall into the water, and other vegetation.
In a fish tank, Oscars will love to eat big food pellets, fish food for jumbos, crickets, mealworms, snails, and even freeze-dried krill.
Like many other fish, Oscars love to eat and beg for food, even if they are already full. Adjust their portion size adequately.
Keep your eyes on their food variety. Consider adding supplements with essential vitamins and minerals (avoiding the famous hole in the head disease).