Choosing Suitable Oscar Fish Tankmates

Is your tank big enough?

I'll get straight to the point, is your aquarium big enough for one Oscar, plus some tankmates? You should already know that 55 gallons is the absolute minimum for one adult Oscar. If your aquarium does not meet this requirement then you have two choices, either stop reading now and enjoy what you've already got, or upgrade your aquarium by at least 75% and then come back and read the rest of the page. Sorry if that sounds a little bit harsh, but that really is your only two options. Most of the fish I am going to recommend as tank mates will require a minimum of 50 gallons just for themselves, not including the Oscar.

Choosing tank mates that are suitable

Remember that you can't put any fish in with an Oscar, you've got to choose fish that will be able to live in harmony with your Oscar. First and foremost, you cannot put small community fish in with an Oscar fish because they will just be an easy source of food. I would advise not adding anything less than 5 inches to an aquarium that contains an adult Oscar fish. The type of fish that you add to an aquarium is also important. For instance, we wouldn't recommend angelfish as a tank mate because they are quite delicate with their long flowing fins, plus they actually prefer the taller type aquariums. Tankmates don't necessarily have to be semi-aggressive themselves, shoaling fish such as Silver Dollars make an excellent tankmate because they are on the move all the time and feel safe amongst numbers. Some species of bottom-dwelling fish are sometimes a good alternative because they don't really come into contact with Oscars who tend to stick to the mid-or top layers of the water most of the time. Some smaller species of cichlids make very good tankmates because even though they are quite small, they still have the ability to stand up for themselves.

Beware of catfish

There are lots of different species of catfish in the world, quite a lot of them come from South America. Catfish do make very good tankmates for your Oscar, however, some people have encountered problems when trying to keep the smaller species of catfish with their Oscar.

Predatory fish always swallow their prey headfirst in order ensure all the fins are folded back and don't catch in the throat. When an Oscar decides it fancies catfish for dinner it will often take the catfish in its mouth and try and swallow it. When it realises that it's not going to be able to do this it tries to expel it. This is when problems arise. A lot of catfish have got spikes built into their fins. These spikes are extremely sharp as a lot of fishermen have found out. What happens is the spikes dig into the Oscars throat or mouth and the Oscar cannot spit the catfish out. Over the years, we've probably had about five cases of this exact thing happening. If my memory serves me well, at least one Oscar actually died because the person couldn't get the catfish out in time. The other cases involved the Oscars owner having to manually remove the fish from the tank and use tweezers to get the catfish out of the mouth of the Oscar. So really what I'm trying to get across is that even though catfish are a good tank mate, small catfish like Pictus species that don't grow much more than 6 inches could be a problem if purchased when very small.

Beware of fish that grow very big

This might sound like a bit of an obvious thing to say, but you've got to make sure you know what you are buying and how big it's going to get. When you buy a dog you know how big it's going to get, the same thing should apply when you buy a fish. A reputable fish store should have information listed on the front of the aquarium stating exactly how big the fish will get.

Pacu Some fish stores sell what a lot of people assume are Piranha. In fact, in a lot of cases, these are Pacu, a vegetarian cousin of the Piranha. Unless you are an experienced fish keeper with a very large aquarium, these type of fish are completely unsuitable for the majority of fish tanks as they get extremely big. Pacu do actually have the potential to reach 36 inches. Plecostomus
Another fish which you are bound to come across at your fish store is called the Plecostomus. Although not always obvious to some people, they are also a member of the catfish family. These fish are primarily algae eaters but will scavenge on any food other fish leave behind. These are normally sold at fairly small sizes, anywhere between two and 3 inches. However, there are a few species of Plecostomus that can easily exceed 24 inches and weigh several pounds. A lot of people buy them because they think they are going to keep the aquarium clean of algae. To a certain extent, that is true, some of these fish will keep the glass spotless. However, I'm sure you've heard of the saying, "what goes in, has to come out". These fish are the exception, what goes in comes out in gargantuan amounts of poo. They are also big polluters of aquarium water so my advice is don't be fooled into thinking this fish is going to save your work, it won't, in fact, it will actually make more work for you in the long run. The most common of these species found in fish stores are the Sailfin and Common, both of which are not suitable for anyone with aquariums less than 100 gallons. There are quite a few species of this fish that don't get any bigger than six or 7 inches so you may be better off getting one of these If you are limited in space.

Black Banded Leporinus - Leporinus fasciatus

Leporinus make wonderful tank mates

A few suitable tankmates

Silver Dollars - Metynnis hypsauchen - 6"

Silver Dollars don't like being on their own so should be kept in groups of a minimum of three. They are extremely placid and make excellent tank mates. Make sure that you have a supply of vegetarian food if you keep silver dollars more info...

Black Convict Cichlids - Archocentrus nigrofasciatus- 6"

Although the Black Convict doesn't really get much bigger than 6 inches, it still makes an excellent choice for tank mate for an Oscar fish. I would advise putting in either a couple of pieces of rocks made into a cave, or a piece of wood as the black convict will appreciate the cover

Severum - Heros Severus - 12"

Severums really do make excellent tank mates for Oscars as they can stand up for themselves perfectly okay and are more than capable of competing for food more info...

Jade Eyed Cichlid - Cryptoheros spilurus - 6"

The Jade Eyed Cichlid is a Central American cichlid. Whereas I'm not in favour of mixing fish from different parts of the world, this was one cichlids that did work well with my Oscars.

Black Banded Leporinus - Leporinus fasciatus - 12"

I absolutely adore my Leporinus, they are not aggressive and keep themselves to themselves. However they can occasionally nip at other fishes fins but it's not something you should worry about. They can be a little timid and skittish so any sudden movements in front of the tank will startle them. These fish absolutely love peas

Jurupari Earth Eater - Satanoperca jurupari - 10"

These Earth Eater fish are very placid & like being in groups, from my experience they don't do very well on their own. They will eat sinking food and blood worm so can compete for food easily. If you have a group of them they are fantastic addition to your aquarium

Blue Acara - Andinoacara pulcher - 8"

These little chaps can be fairly aggressive so will stand up to Oscars. My advice would be to purchase these as adults as they can find it difficult to compete for food when they are very small, especially if you got more than one Oscar.

Firemouth - Thorichthys meeki - 8"

This relatively small cichlid that doesn't normally exceed 8 inches is another fish that will more than stick up for itself if sharing a tank with an Oscar

Plecostomus - Hypostomus plecostomus - 18" +

Often abbreviated to Plecs or Plecos, these bottom dwelling fish are very popular as people buy them for their ability to cleanse the tank of algae. However, please be aware that some species of Pleco can well exceed 12 inches, in fact some species such as the Sailfin and Common can even exceed 18 inches. The larger specimens of Pleco need large aquariums, in excess of 100 gallons so please don't buy these fish unless you have the facility to house one properly

Chocolate Cichlids - Hypselecara temporalis - 12"

Chocolate cichlids come from South America. Even though these cichlids can easily reach 12 inches, they are actually very peaceful. So long as your Oscar isn't aggressive, and your aquarium size permits, a Chocolate cichlid could make a very good tank mate

Obviously there are many more fish that you could put in with your Oscar, these are just a few Examples of the more common tank mates that people keep with their Oscar fish.

The sizes quoted on this page are meant to give you an idea of how big these fish can get. It isn't guaranteed that these fish will get this big in your aquarium. If you are unsure about what fish to mix with your Oscars then please visit our forum and seek advice...