If you’ve never heard of an Oscar Fish before, you might be wondering, “Are they gold? Are they statuesque? Award-worthy?”
Oscar Fish are none of those things in particular, but they do have an intriguing name that should make you want to find out more. As far as awards go, they are rather deserving of a pride of place spot in your tank if you are looking to branch into a larger-sized aquarium.
They are also known as Tiger Oscars or Velvet Cichlids instead of standard Oscar Fish.
Oscars are, however, not for the faint of heart or a novice hobbyist! These are species that can look deceptively calm, but underneath that calm facade lies a more aggressive species. Being a Cichlid, this should not come as a complete surprise, but this does bear mentioning.
Hailing from South America, these are large freshwater fish native to Brazil, Peru, and most northern countries that border the Amazon river.
They are a lot of fun to observe and are known for being intelligent characters which will display a lot of personality. The big ‘But’ in this overview is that they can run large, live a long time, and can be cantankerous to handle.
If you’re up to the challenge, then read on for why the Oscar Fish might be the next step in your fish-keeping career.
Oscar Fish Behavior
Oscars are much larger than your average tank specimen for the average hobbyist. Some experts recommend that they are kept as a single species and aren’t left to mingle and get involved with other types of fish.
They are social fish and should be kept in either pairs or five if you have room. Try to avoid three as one will likely be left out from the bonded pair, and this can be stressful.
When you factor in that they are quite a territorial species, with a penchant to act out with aggressive behaviors, you will soon realize why they are not for the novice and should only be handled by those suitably experienced. Although they are not aggressive 24/7, the unpredictability is why caution is recommended.
Oscars have got teeth in their mouths. These can be seen in their jaws as well as in their throats. As such, you should not put your hand in the tank. These fish can and will attack, and a nip or grab will not go unnoticed. If you absolutely need to reach in, use a partition to protect yourself as they are unpredictable.
Particular precaution should be taken if breeding is on the cards or if eggs are already present as they will defend and guard their developing fry with considerable gusto.
Not only can they be aggressive towards you, their keeper, but they will also have aggression towards each other. This applies to both sexes!
While they are notably curious, beautiful, playful, and can often be seen as ‘problem-solving,’ at their most basic level, they are a predator and will treat anything else as such in your tank. They are popular for a reason, though. For a keeper who can handle their outbursts, they will reward you with some great observations and bags of personality.
We will look at a few indicators of what to look out for in terms of aggression and ways to defuse behaviors if things are getting a little heady in your setup.
Aggressive Behavior
Aggression can sometimes be misinterpreted as it also looks a lot like typical mating behavior!
Things to keep an eye out for are things like:
- Chasing behavior (other Oscars or any other fish in the tank)
- Coloration intensifying on their bodies
- Biting and nipping, even mouth-to-mouth with other fish
- Circling motions while swimming with fins fanned out to make them look larger
- Fanning out of fins while approaching or being approached by other fish
- Eye color changes
Ways To Reduce Aggression And Bullying
There are some ways to put a damper on aggression in your tank between Oscars or between Oscars and other fish in your tank.
Some good options worth attempting include:
- Increase hiding places for the harassed fish
- Increase feedings
- Rearrange tank decor to reset territories
- Increase tank size
- Lower tank temperature outside of breeding season
- Isolate the bullying fish for a timeout either temporarily or permanently if need be
Oscar Fish Lifespan
Oscar Fish are a real commitment purchase as they can easily live for 20 years plus. On average, they will live anywhere from 10-20 years, so do bear this in mind when deciding to take the Oscar plunge.
These fish also grow rather quickly, so do not purchase one with a smaller-sized tank, thinking you have a few years before needing to upgrade. You should have an appropriately sized tank from the start to accommodate these fish.
We will discuss more on tank requirements a little later in this article.
Oscar Fish Appearance
At full maturity, they will usually be 10-14 inches in length, so you can appreciate the size of the tank needed on that fact alone.
Captive Oscars, which are what you are more likely to encounter in the trade, have an olive base color and are more vibrantly marked with contrast colors than their wild counterparts.
Varieties include Tiger Oscars, Albino tiger, Red, Albino red, Sunshine, Golden, Blueberry, and Strawberry markings.
Their bodies are long and oval-shaped, and they have a dorsal and anal fin that extends to the caudal (tail) fin. Colors are then splotchy on the body, and as noted earlier, with behavior, it can change over time.
Their eyes are large and look inviting, which is why many people are drawn to these fish.
Oscar Fish Habitat And Tank Requirements
As always, we want to achieve optimum health for fish we keep in captivity by closely mimicking their natural habitat.
In the wild, Oscars prefer strong flowing waters and sandy soft river bottoms that are punctuated by rock, vegetation, and wood or other debris.
Large bioloads are to be expected with fish this size, as well as requirements for plenty of space to move and things to keep these smart cookies occupied. Bored fish will often become aggressive fish!
Tank Conditions
With large tanks, you will need to ensure that your water is well cycled, and this can take time, not to be rushed.
These fish are graceful but powerful swimmers, so a lid is recommended as they can do some mighty jumps. Keep a distance between the lid and the water surface, or they can injure themselves on impact.
Substrate should be sandy and silty; avoid sharper rocks as these fish are diggers.
Vegetation should be present as much as open water swimming areas, so keep plantlike in patches. Ideally, you will be looking for live, rooted plants that can avoid being dug up (use mesh if needed) mixed in with some floating plants.
Good plants to consider include Java Fern, Java Moss, and Salvinia Natans. Do not be discouraged if you diligently plant vegetation only to find that your Oscars end up rearranging everything. They will continue to do this as they see fit, so it’s best not to get too hung on this aspect.
Avoid cheaper plastics for decor or anything that they could outgrow easily and get trapped in. They can grow up to an inch a month until fully grown, so this is quite important!
Filtration should be huge and of high quality. You would do well to include air curtains for added oxygenation as well as a built-in heater and thermometer to keep things stable.
Expect to become a water testing expert as you should be monitoring weekly for ammonia, nitrates, and pH.
Water changes will need to be twice weekly and at least 25% changed over as they are messy fish.
Water conditions should be noted and maintained as follows:
- pH of 6.5-7.5
- Water hardness between 12-15 dGH
- Temperature between 74-81ºF (23-27ºC)
- Lighting medium to low
Tank Size
The minimum tank size needed is 150 gallons and up for mature Oscars, ideally 55 gallons per fish as a minimum. The rule of thumb is that the bigger, the better, which will keep your water quality higher and tank cleaner as they create a lot of waste.
Size of the tank and grouping these fish smartly into suitable numbers for pairing without excluding fish is very important.
Choosing Tank Mates For Oscar Fish
When it comes to finding Oscar-friendly fish, great care needs to be taken. As already mentioned, it may be easier and almost preferable to keep Oscars as the sole species of your tank setup. But if you do want to mix it up, you should be prepared for some fractious behaviors and potential for conflict.
Larger, passive fish who don’t want to engage with Oscars or who are unlikely to be intimidated and can defend themselves are your best bet. Needless to say, having even larger fish will mean a bigger tank in all likelihood and thus a bigger budget!
Some examples to choose to coexist with Oscars might include:
- Silver Dollars
- Sailfin Plecos
- Jack Dempseys
- Green Terrors
- Arowanas
- Bichirs
- Other Cichlids such as Convict, Firemouth, Jaguar, or Severum
Avoid any small fish, invertebrates, or snails. They will end up as food in short order!
Oscar Fish Common Health Issues
Oscars are susceptible to the typical freshwater fish afflictions such as Ich, Fin Rot, and
Less well-known is ‘Hole in the Head’ disease, where ulcers and cavities begin to form around the head area. Often attributed to poor nutrition, it can be stemmed from progressing by increasing the variety of foods and switching up your current offerings to something of higher quality.
It is often the case that the biggest health issue for Oscar keepers is managing injuries from other fish. Wounds make them more susceptible to bacteria and fungal infections. This is yet another reason to keep your tank as clean as possible.
They are also well suited to antibiotic treatments as they have sturdy scales, so managing these typical health issues do not carry a huge risk for your cohort.
How To Breed Oscar Fish
Oscars are not straightforward to breed, although pairs are monogamous and mate for life. These fish would be considered ‘advanced’ in terms of difficulty level for achieving a successful reproductive cycle.
Most Oscars purchased are not suitable for breeding, and even if mating behaviors are observed, eggs are often not viable, or juveniles will have deformities.
These are choosy fish, and because they mate for life and are also very difficult to sex, you cannot just get a pair and expect them to reproduce.
If you are determined to breed Oscars, you should investigate purchasing an established pairing or a juvenile group that will pair off as they grow.
If you manage to get your hands on a pair, you will need to perform a large water change of about 20-30% for several days. Lower temperatures signal pending rain, and you may simulate rainfall by sprinkling the tanks for a few minutes a few times a day to simulate the rainy season when they normally breed.
Once eggs have hatched, they will protect their fry until they can defend themselves, but infighting amongst fry is the bigger worry as the larger fry will eat the smaller ones, so isolating may be necessary.
Conclusion
Not only are Oscars a fairly aspirational fish for fish-keeping, but they are almost representative of taking the hobby to the next level.
They take a lot of work, time, and patience to look after but are incredibly rewarding for the hobbyist willing to put in the effort required.
One of the neatest facts about these fish is that they are so intelligent they recognize their owners and are quite reactive in their behavior, playful in nature. Some have taken to calling them ‘water dogs’ because of how pronounced this behavior is.
If you think you are ready to have the ‘dog of the fish world’ in your tank, step up to the podium and win with an Oscar of your very own.
