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| Oscar photo from Flickr Creative Commons, user daniella vereeken |
Scientific Name: Astronotus ocellatus
Origin: Amazon River
Life-span: over 20 years
Temperature: 74° to 83°F (23 to 30°C)
Food: Flake food, bloodworms, tubifex, brine shrimp, frozen foods, cichlid pellets. Some say feeder goldfish, however I don't recommend this because they don't offer enough nutrition to offset the risk of introducing disease into your aquarium.
Care: Oscars can grow over a foot long and so it is recommended that you give them at least 30 gallons of water. They will rearrange the gravel and decorations in an aquarium so it is best to use larger, heavier decorations. They enjoy places to hide so keep this in mind when setting up your aquarium. These fish are territorial and aggressive so they do best alone or with other oscars. Some people have successfully kept Oscars with other species, however this can change without notice and all of a sudden the Oscar can attack and kill other fish without giving any prior warning signs.
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| Oscar photo from Flickr Creative Commons, user daniella vereeken |
Weekly water changes are necessary, as they are for all aquariums. They are messier fish than others so a siphon cleaner will help you greatly. Monitor the temperature of your aquarium to keep your fish healthy.
Sexing: Very difficult if not impossible. The easiest way is to get a group of them and let them pair off by themselves.
Breeding: These fish can lay up to 1000 eggs, so don't try to breed them unless you have a plan of action for raising all the fish and have somewhere for them to go! However, sometimes if you have a group of them, it just happens.
To condition your Oscars for breeding, start by doing more frequent water changes. This stimulates them by making them think it's the rainy season. Also, vary their food. Provide them with a flat horizontal surface to lay eggs on. Flat rocks, including slate, work great. The Oscars will clean it with their mouths prior to laying and fertilizing the eggs.
Oscars will begin a breeding ritual which includes lip-locking. To a novice this will appear that they are fighting. They also chase each other in circles around the tank, taking nips at each others fins. They will quit eating and within a couple days they will lay and fertilize their eggs.
The eggs will hatch within two or three days. During this time the parents will guard the eggs and the area around it from other fish. Beware, however, that plecos sometimes will eat the eggs while Oscars are "sleeping". When it's dark, the nocturnal plecos can sneak in and devour the eggs. It's best not to have a pleco in the tank if you want the eggs to survive. Also, if the eggs turn white, it means they were not fertilized.
When the eggs hatch the fry will stay on the surface for a while. They have a heavy yolk sack on their abdomen that makes it difficult for them to move. They will not eat until they use up the yolk sac. Once they begin swimming, newly hatched brine shrimp make a great food for the fry.
The parents and other tank-mates may eat the fry. If you want to prevent this, remove the object that the eggs are laid on and put it in a separate tank. Make sure that there is moving water, whether it be from an aerator or a filter, otherwise the eggs will mold and/or grow fungus.
Good luck! Please feel free to add your own experiences in the comments below!
