The oscar (Astronotus ocellatus) also known as the tiger oscar, is large fish that has long been a staple of the aquarium trade. Originally found in South America, it can now be found throughout the world, with large self-sustaining populations in China, Australia and the United States.

In the wild, oscars are mainly found in slow moving rivers, though some have been found in fast moving, white water environments. In these environments, the oscars will often shelter in riffles or near submerged driftwood.

Oscars are by no means a small fish, and some can reach a staggering 18 inches in a home aquarium. With that being said, a far more common size is 11-12 inches. This smaller size can be caused by several factors, but most oscars suffer from stunted growth from being kept in cramped conditions for most off their life.

Not only are they large, but they can also live up to two decades in captivity. The commitment that oscars require should not be underestimated, and even ones kept in less than optimal conditions will usually live for at least a decade. So be prepared to shell out a significant amount of money and time if you are considering purchasing an oscar.

Feeding

After carrying out a survey on our community forum, I have compiled a list of various types of food that our members feed their Oscars.  Some of the commercially available food listed may be unavailable in your particular country. However much of the food listed is easily found in your backyard, in other words its FREE!!!.  Just one warning before feeding harvested food to your Oscars, do not collect food from areas of the garden that has been treated with pesticides, whereas there is little chance that you'll actually kill you Oscar, you may well upset its stomach so better be safe than sorry.

Commercially Available Pellet Food

Hikari Cichlid Gold floating (Available Sizes - baby pellet, mini pellet, medium pellet, large pellet)

Hikari Cichlid Gold Sinking (Available Sizes - mini pellet, medium pellet)

Hikari Cichlid Bio Gold (Available Sizes - mini pellet, medium pellet)

Hikari Cichlid Staple (Available Sizes - baby pellet, mini pellet, medium pellet, large pellet)

Tetra XL Cichlid Sticks

TetraCichlid Food Sticks

Tetra Dorimin

Tetra Prima

Aqueon Cichlid Pellets

Aqueon Herbivore Cichlid Pellets

Ocean Nutrition Cichlid Omni Pellets

Pure Aquatic Cichlid Pellets

Frozen Food

Shrimp

Cockles (fresh shelled)

Mussels (fresh shelled)

Bloodworm

Beef Heart

Hikari Frozen Krill

Hikari Frozen Blood

Hikari Frozen Brine Shrimp

Hikari Frozen Silversides

Ocean Nutrition Frozen Blood Worm

Ocean Nutrition Super Shrimp

Ocean Nutrition Lance Fish

Ocean Nutrition Whole Mussel

Ocean Nutrition Chopped Mussels

Ocean Nutrition White Shrimp

Ocean Nutrition Frozen Clams

San Francisco Bay Brand® Sally's Frozen Emerald Entree™ Fish Food

Live Food

Crickets

Grasshoppers

Garden Worms (nightcrawlers)

Super Worm

Shrimp (probably easier to buy frozen shrimp)

Fish (beware of cheap feeders that can contain disease}

Beetles

Fresh Food

Squid

Salmon

Scallops

Freeze-Dried Food

Tubifex Worms

Flukers Freeze-Dried Crickets

Flukers Freeze-Dried Mealworms

Interpet Freeze Dried Krill

Fruits and Vegetables

Peas

Green Beans

Strawberries

Banana

Housing

If you are planning on keeping Oscars then please consider exactly what type of fish you will be getting. You may already have an aquarium, however under no circumstances rush out and buy the first Oscar you see. Step back for one minute, take a good look at your tank and ask yourself if it is big enough to house an Oscar. If you have done your research, you will know that Oscars can get very big. Big fish require big tanks. There are two very good reasons for keeping your Oscar in a big tank. Firstly, if you house a large fish in a very small tank, you may find that you start having water quality problems. If you continue to expose your Oscar to poor water conditions than it can affect its health and even prove fatal. Also, is it fair to restrict a large fish to a very small amount of space?  Personally, I absolutely hate seeing a large fish cramped up in a tiny little tank where it has no room to move, it just makes my blood boil.

You don't have to go to the extremes of getting a tank as big as the one on this page which is 300 gallons and measures 8' x 2.5' x 2.5'. However we always recommend going for the absolute largest tank you can afford and house if you intend on keeping a large Cichlid like an Oscar Fish. If I was starting over then I wouldn't go any smaller than 75 gallons if I was planning on one Oscar. However many people seem to agree that 55 gallons is about the minimum size aquarium if you want to keep one adult Oscar. If you plan on keeping two Oscars then you will be looking at a tank in excess of 100 gallons, please do not try to keep two Oscars in anything less than 100 gallons. Commercially available aquariums probably won't exceed much more than 200 gallons, so if you are planning on a very large tank with Oscars and lots of other big fish you may have to go down the route of having a custom aquarium made. In the UK that are quite a few manufacturers to build aquariums to that customer specifications.  

Oscars are adorable fish, it's no wonder that people fall in love with them. However, they do require that little bit of extra attention, so please only buy one of these fish if you know you can provide it with a suitable home.

Breeding

Oscar fish can be breed in aquariums as long as you provide them with favourable conditions. To begin with, the aquarium must be large enough. Oscars are large cichlids and their size can exceed one foot. To get a breeding pair, you must house 6 young Oscars together and let them form their own pairs. Make sure you choose healthy Oscars from different broods. It can be hard to sex young Oscars, but you will hopefully get at least one pair from 6 individuals. If you don’t want to wait and let Oscars grow up together, you can instead buy a breeding pair but this is usually much more expensive. The stress and disturbance experienced by the fish when you move them from their old aquarium can also cause them to brake up and stop being a breeding pair. 

Once a pair has been formed you should remove the other fish from the aquarium, since breeding Oscars are highly territorial and can hurt intruding fish. If the spawning does not commence immediately there is not easy fix that can kick start it. What you can do is provide the pair with suitable conditions and wait for the spawning to start. The courtship behaviour can be very violent – sometimes too violent and resulting in the death of one of the Oscars before any offspring has been produced. Oscars will do well in soft acidic water as well as in harder alkaline water, as long as you avoid any extremes. Keeping the conditions similar to their native home in Central America is always a good idea. Frequent water changes are important to ensure suitable water chemistry and low levels of soluble waste. Do not change more than 25 percent of the water at once. Changing 20-25 percent of the water once or twice a week is a good rule of thumb. Efficient filtration is also required since Oscars are renowned for being messy eaters and producing plenty of waste. If you have a 50 gallon aquarium you should ideally use filtration that is recommended for a 100 gallon aquarium.