Oscars or Astronotus ocellatus are one of the largest cichlids that are kept in home aquariums. They can grow to one foot or more and weigh up to five lbs. The name ocellatus refer to the eye-like spot near the tail. The first time I kept Oscar my brother gave four adults when he was moving from his college apartment. He could not take them since he was moving to his new job. I was keeping them in two 30 gallon tanks. Oscar are different from regular fish. There are very bright and react to their owners. They will watch what you are doing in the room.  They really do have a personality of their own. They are predators and will eat small fish whole as fast as they can swallow. They are trouble free for the most part.

Oscars from the Amazon basin. They are a few variation of color. There is a red form that has lots of orange of the sides of the body. They is albino form. There is a long fin form. Tiger Stripe is a hybrid between normal and red with lots of orange but not completely covering the sides of the body. You can find fish with any combination of these traits.

Water: Oscar prefer the their water wet. Seriously they will adapt to any type of water. The most important thing is that water is clean. The water should be partial changed every week. Sometimes twice a week. If they are acting funny the water is probably dirty. If they is a high level of waste the pH can be affected. If it is very low, baking soda can be added to bring the water closer to pH to neutral.

Temperature: They do best in low seventies to about eighty. They are adaptive. They are found in many waterway is Florida because some escaped.

Aquarium furniture: Oscar like to re-arranging things in their home. They dig gravel. They can spit gravel several inches through the water. Plastic plant since they will kill real plants. I have heard that plastic plants described as cichlid chew toys.

Also a word of caution about breakable items in tank don't put them in. They can and will break glass thermometers. I use the plastic tape ones that go outside the tank. My brother told me the number one killer of Oscar is a broken heater. They knock the heater around until it it breaks. Broken heaters have a short and do not turn off slowly cooking the fish. You need to place a small pc pipe with man holes cut into it to allow the heat to escape but protecting the glass heater from hitting the sides of the tank. We have heated the tank for years with this method.

Food: Oscars are eating machines. They think that they are always hungry. They will eat enough to hurt themselves. Flake food is just too small for adult Oscars. They love floating meaty pellet food. I was raising a group of babies. One of the fish would get so excited when I was feeding that he would jump out of the aquarium and land with a thud on the floor. I had to keep heavy rock on the lid to keep inside. You can feed them all live food but it rather expensive and not necessary. One is a while for a treat maybe.

Tank size: They can be kept in any size tank when they are small but adults should be in 55 or 70 gallon tank per pair. They need the room to swim and that size of fish produces lots of waste.

Tank Mates: Most people raise them by themselves. If you raise them with other fish when they are small they will get use to them and leave them alone as adults. A couple of large fish that I have seen kept with them are Silver Dollars and Tinfoil Barbs. Both are very large growing plant eaters. They can easily get seven or eight inches across so you would need a larger tank to hold all of them. When they are larger anything bite sized will be swallowed.

Spawning: These can be a challenge to spawn because of the space needed and finding a fertile pair. The easiest way is the same as Angelfish buy six or more babies. They will pair up when they get old enough. They will fight with each other but if one is attacked both will attack the aggressor. It is hard to sex these fish. The males tend to be bigger but that is not always true. They are a object spawner. They will pick a large rock and clean before laying the eggs. The parent will guard and fan the eggs until they hatch. They can lay up to 2000 eggs at one time. If you are lucky you could raise several hundred of them. You would lots of spaces. And many willing stores to buy some many fish.

There was a fish store in Milwaukee that had a spawning pair in the basement. It is a spectacular sight to see several hundred fry swimming around the proud parents. The easiest first food is brine shrimp. You can switch to other as their grow. They will eat flake food with gusto. When needed move to small pellets and gradually switch to larger ones.

My brother did get his to spawn once. He had a dozen babies died suddenly. He never knew why.



Books: Books about Oscars

If you have any question not covered, contact me. I will be revising this guide in the future.