When selecting tank mates for Oscar fish it is important to take their size, aggression level and water parameters into consideration. Certain species of fish tend to be more compatible with Oscars than others - those which fit easily in their mouths without becoming bullies are most often recommended as potential Oscar tank mates, while large catfish and plecoes as well as oddball species like the bichir or some 6-10" Cichlids will work just as well as tankmates for Oscar.
Loricariidae catfish, more commonly known as armored catfish, make great companions for Oscar fish tanks because they have large but not overgrown the aquarium's capacity while their peaceful temperament can help maintain peace in your aquarium. There are a wide range of Loricariidae species available on the pet market so finding one suitable to your aquarium shouldn't be hard!
As well as Oscar, other recommended companion fish for his or her tank include silver dollar fish, Jack Dempseys and Firemouth cichlids. However, larger cichlids like Texas or Green Terrors could prove too overwhelming for your oscar's delicate disposition.
Many hobbyists find the optimal option is keeping Oscars together from an early age, especially as young. This will allow them to form strong bonds together and reduce aggression issues as they age. If this option appeals to you, ensure there are ample hiding spots so stress doesn't build up in either of their tanks.
