10 Things You Need to Know About Oscar Fish

The Oscar fish is widely considered one of the most popular cichlids by aquarium hobbyists around the world. Renowned for their vibrant, bold coloration and tiger stripe pattern, these fish make a stunning addition to any tank.

10 Things You Need to Know About Oscar Fish

• Origin: South America
• Lifespan: 10-15 years, up to 20 in captivity
• Size: 8-15 inches
• Food/Diet: Omnivore
• Additional Names: Tiger Cichlid, Velvet Cichlid, Oscar Cichlid, Marbled Cichlid
• Variations: Albino, tiger, blue, black, veil tail, lemon, golden, and painted

Are you interested in starting an Oscar fish aquarium, or adding an Oscar fish to your existing set up? These gorgeous fish are packed with spunky personalities and are a favorite among many hobbyists. But you’ll need to know a few things before you introduce one of these flaming personalities to your community.

For the most part, caring for an Oscar fish is the same as caring for any cichlid. However, there are two important aspects to know about these fish before committing to their husbandry. One is that they are extremely territorial and will attack most fish in the community once they’ve established their dominance, especially if they’ve grown to a larger size than the rest. The second is that there are some important dietary considerations to take into account; particularly, these cichlids will need an adequate source of certain vitamins and minerals in their diet to avoid potential health issues.

Oscars aren’t ideal for true beginners, who may not have an established tank or community yet. Fish keepers with adequate knowledge of tropical community tanks above 50 gallons will find keeping these cichlids quite easy. Water testing and supplement dosing are essential knowledge and skills, as well as how to spot potential health issues in cichlids. Understanding of community behavior and aggression is vital to ensuring the overall health of the tank. While not absolutely necessary, bioactive tanks make ideal settings for these fish native to South America and its lush, tropical freshwaters.

Searching for aquatic plants of the internet for Oscar, might suggest the keyword “cichlid-proof.” These fish are omnivorous and are known to nibble on vegetation. Natural vegetation is a fantastic way to boost the health and immunity of your fish. Still, having an expensive plant devoured before it has the chance to grow back can be frustrating. Some of the best plants for keeping alongside cichlids include:

• Anubias
• Java fern
• Amazon sword
• Vallisneria
• Java moss

These plants are all known to be fairly tolerant to a variety of water conditions and the occasional nibble. They are hardy, and don’t require an extensive knowledge of aquatic cultivation to flourish in the tank. They are wonderful for those interested in beginning a bioactive tank.

Oscars, like most cichlids, are incredibly territorial. If they feel like another fish is encroaching on their territory, then they will not hesitate to attack. That’s why it’s important to carefully consider the ensemble of fish in your tank and how they will interact with each other. Cichlids can grow to be quite large, so most fish smaller than them will fall victim to their aggression. Cichlids in general make good companions with two kinds of fish: tame fish larger than them and other cichlids.

A common mistake among aquarists is to bring home an Oscar small in size and add it to their existing community with tetras, goldfish, silver dollars, and other common species. These fish may be larger than the new Oscar, but not for long. Cichlids are loved for their large size and rapid growth and the fish will no longer be able to withstand the aggression of the Oscar.

Some cichlids can be kept in a community tank with careful consideration of the species within it, but for the most part, it’s best to have an all-cichlid tank.

That doesn’t mean cichlids get along just fine with their own kind, however. Oscars are known to attack fellow cichlids! Males in particular are usually the ones responsible for this kind of behavior. You might consider keeping one male with an accompanying sorority, or one male per type or variation. Males will most often go after other fish that look like them, so you could potentially get away with having multiple males if they all contrast with each other. This is also ideal if you plan on breeding your Oscars.

Breeding cichlids can be a highly profitable enterprise, and a great option for those looking to fill a 100 gallon tank or larger. Breeding any fish, however comes with its challenges. Most keepers are aware that established community fish will target young fry in the tank, and this is especially true for cichlids. To breed Oscars, you’ll need to optimize your tank setup in a few ways.

One helpful thing to do is to minimize the amount of males in the tank. Dealing with aggressive tendencies that based on mating can be counterintuitive to the breeding process. Second, you’ll need to ensure that your water parameters and tank health are up to par. Fish will only breed when they are in a well maintained, comfortable environment.

Female Oscars will carry unfertilized eggs in their mouths. In some cichlids, you can tell which females are carrying eggs by looking for a distinctive bulge around their mouth. If your Oscar is large enough, you might be able to do this. Otherwise, it’s exceptionally difficult to distinguish the sex of an Oscar because males and females are nearly identical. A surefire method to start off with a pre-sexed pair.

Another way to optimize your tank for breeding is to have cichlids that have grown up together since they were immature. This familiarity will make cichlids more likely to breed, and less likely to be aggressive with one another. You may notice two Oscars mating by doing their distinctive dance and tail slap. The pair will lock lips (literally!) as the male fertilizes the eggs within the female’s mouth.

From there, success in hatching fry is largely dependent upon the female. A female that is stressed may swallow or spit out the eggs. You should provide ample hiding spaces, such as rocks, plants, or driftwood, as this will help keep the female and her young fry comfortable (and not vulnerable). It is also an option to retain the female in another tank. This setup is usually ideal for most breeding situations; however, moving the female to a new habitat can cause stress.

There is no true way a fish keeper can “hack” the breeding process or force it to happen. It’s purely natural, and to this day, we still aren’t entirely sure of the specifics behind getting certain species to mate. What you can do, however, is ensure the water is clean and warm, which is said by many experienced keepers to promote mating behavior. Ensure your Oscars are fed a variety of vegetation and frozen/live food. Also ensure that your Oscars are supplemented appropriately and that they are free of diseases, such as the common “hole in the head.”

Size of tank is important for Oscar

Oscars for sale at your local fish store may be very small in size, perhaps about 2 inches. It’s possible to keep a small school of juveniles in a 20 gallon tank. But like the infamous goldfish, Oscars grow up big, and fast. As the fish grow, they’ll increase the biological load on your aquarium.

Too many fish in a tank will overwhelm the filtering cycle and could lead to dangerous ammonia spikes. A school of medium sized cichlids would do best in a tank that is at least 55 gallons. Consider following the rule of thumb of a gallon for every inch of fish.

Canister filters are the best for Oscar fish as they consume a lot of food and with the size of the tank, it will help to keep the water clean. This also can help to set the right environment if you are considering growing your Oscar population.

With Oscar’s vibrant, bold coloration, using LED lighting, will bring out the best in their color and stripe patterns.

Always be on the lookout for signs of disease in your fish, such as lethargic behavior, refusing to eat, or any new open sores or wounds. Like all fish, Oscars are prone to parasites and bacterial infections like ich. Cichlids are prone to getting a disease called “hole in the head,” which is a noticeable depression in the head region along with rapid weight loss and lethargy.

Other common diseases among cichlids include malawi bloat, columnaris, and fin rot. Be on the look out for any injuries as a result of fighting with other fish, as these injuries can become infected with columnaris or another bacteria quite quickly. And remember that while rare, fish can transmit zoonotic pathogens to humans, like tuberculosis. Always thoroughly sanitize your hands after working in your tank.

Oscar fish aren’t all violent as they’re cracked up to be. In fact, they’re beloved for their intense personalities and similar qualities to that of, well, a dog! These expressive fish will build recognition with their keepers and create a lively and dynamic tank. Oscars are just one type of cichlid (and a big one at that), but a great option for anyone looking to explore this fascinating breed.

Always remember to quarantine your fish before adding them to an existing tank, and cycle your tank if it’s new. Happy fish keeping