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What Types of Fish Can Be Kept with Oscars
Finding the right tank mates for these Oscar fish (Astronotus ocellatus) can be challenging due to their aggressive and territorial nature. While the process of selecting compatible tank mates is not easy, it is possible. The process starts with understanding what characteristics to look for.
Here are characteristics to look for in tank mates for Oscar fish:
- Size: The fish should be quite large so that they do not get consumed by the Oscar fish. Fish that are too small might be eaten by Oscars.
- Temperament: Tank mates should not be overly aggressive. They shouldn’t be constantly fighting Oscars, making the tank environment hostile. With that said, they shouldn’t be too timid or fragile fish either. Oscars may pick at their tank mates once in a while, and they should be able to resist it.
- Diet: The fish should not be picky eaters. If they’re picky eaters, every time you try to feed them, their food might get eaten by the Oscar fish.
- Habitat: The fish should be able to thrive in the same conditions as the Oscar fish. This includes temperature, pH, and overall tank setup.
While finding suitable tank mates for Oscars can be a challenge, it’s definitely possible. In fact, there are plenty of aquarium fish that will thrive as Oscar tank mates.
Here’s a list of some of the best Oscar tank mates:
Keeping Oscars with other Oscars is an option. Just because they are the same species, it doesn’t mean that there will be no aggression. However, given the right tank size and tank setup, it’s definitely possible to have a tank with multiple Oscar fish.
Convict Cichlids (Amatitlania nigrofasciata) are attractive fish known for their aggressive and territorial behavior. They grow up to 6 inches, so they are smaller than Oscar fish. Even though they are smaller in size, they are very tough fish. Even if they get bullied by Oscar fish a little, they will not shy away.
Green Terror Cichlid
Green Terror Cichlids (Aequidens rivulatus) are beautiful and can grow quite large. They grow to around 8 inches. They can be aggressive and territorial, similar to Oscar fish. Therefore, they should only be kept with Oscars in a sufficiently large tank to prevent territorial disputes.
Silver Dollars (Metynnis argenteus) are peaceful schooling fish that grow up to 6 inches long. Their size and round body shape makes them less likely to be eaten by Oscars. Their peaceful nature also makes them less likely to provoke the Oscar, making them good tank mates.
Jaguar Cichlids (Parachromis managuensis) are attractive fish that can grow quite large. They grow to around 12-16 inches in captivity. They can be semi-aggressive, and they are able to hold their own with Oscars. They should only be kept with Oscars in a sufficiently large tank with experienced fish keepers due to their potential aggression.
Sailfin Plecos (Pterygoplichthys gibbiceps) are large catfish that have tough, plate-like armor across most of their bodies, making them difficult for Oscars to eat. They can coexist with Oscars as long as the Pleco is too big to fit in the Oscar’s mouth. The average adult size is 15-20 inches.
Common Plecos (Hypostomus plecostomus) are very popular freshwater aquarium fish known for its ability to help keep the tank clean by eating algae. It can grow quite large, up to 24 inches, and has a peaceful temperament. It makes a good tank mate for Oscar fish because of its size and non-aggressive nature.
Firemouth Cichlid (Thorichthys meeki) is a brightly colored species that can grow up to 6 inches. Even though they are smaller than Oscars, they are tough fish that will hold their own. They are known for their hardiness and easy care. Since they are territorial fish, having an adequate tank size would be important.
Jewel cichlids (Hemichromis bimaculatus) are known for their beautiful, bright colors and can grow up to 6 inches. They can be somewhat aggressive when they are spawning, but they are generally not aggressive towards other fish. They make good tank mates for Oscar fish since they are able to hold their own.
Jack Dempseys (Rocio octofasciata) are large, colorful fish that can grow up to 10 inches. They are known for their aggressive nature, but in a large enough tank, they can coexist peacefully with Oscar fish.
Tinfoil Barbs (Barbonymus schwanenfeldii) are large, active fish that can grow up to 14 inches. They are peaceful and schooling fish that prefer to live in groups. Their size and peaceful nature make them a suitable tank mate for Oscar fish.
Blue Acaras (Aequidens pulcher) are relatively peaceful cichlids that can grow up to 8 inches. They are hardy and easy to care for, making them suitable tank mates for Oscar fish.
Ornate Bichirs (Polypterus ornatipinnis) are nocturnal fish that can grow up to 24 inches in length. They are carnivorous and typically ignore other fish in the aquarium. They can be compatible with Oscar fish because they are large and hardy, and can stand a wide range of water parameters.
Demon Eartheater (Satanoperca jurupari) are relatively peaceful fish that will not bother Oscar fish. They are omnivorous and can adapt to a variety of diets. They can live with Oscar fish because they are large enough, growing to approximately 7 inches, and able to defend themselves.
Silver Arowanas (Osteoglossum bicirrhosum) can grow up to 40 inches in length and are carnivorous. They are not aggressive towards fish too big to be eaten. They can be compatible with Oscar fish because of their large size and similar dietary needs.
These hybrid cichlids are friendly and peaceful creatures that can live up to 15 years in captivity. They are omnivorous and versatile with their diets. They can live with Oscar fish because they are large enough not to be considered food, and they are passive enough not to stress an Oscar. Blood Parrots will grow to around 8 inches.
Clown Loach (Chromobotia macracanthus) are peaceful, sociable fish that generally get along well with other fish of similar size. They are omnivorous and will eat almost anything if the opportunity presents itself. They can live with Oscar fish because they are large enough not to be considered food, and they do not display aggression unless threatened. Clown Loach grow to around 8-12 inches.
Severums (Heros spp.) are generally peaceful and more community-oriented. They prefer to live harmoniously with other fish. They can live with Oscar fish because they are large enough to defend against an Oscar’s aggressive behavior, making them less aggressive tank mates. Severums grow to around 7 inches in size.
The Fire Eel (Mastacembelus erythrotaenia) is a large species of spiny eel native to Southeast Asia. It’s not a true eel, but an elongated fish with a distinctive pointed snout and underslung mouth. It’s suitable as a tank mate for Oscar fish because of its large size and peaceful nature. They can grow up to 40 inches in size.
Black Spotted Eel
The Black Spotted Eel (Mastacembelus dayi) has an elongated body with a long snout. It’s a good-sized eel with imported specimens commonly being up to 20 inches (50 cm) in length. It’s suitable as a tank mate for Oscar fish due to its large size and timid nature.
The Giant Gourami (Osphronemus goramy) is the largest gourami species, sometimes called the True or Common Gourami. It can reach a whopping 18 inches in length. It’s suitable as a tank mate for Oscar fish due to its large size and easy going temperament.
The Red-Tailed Shark (Epalzeorhynchos Bicolor) is a freshwater fish found in Thailand. It’s known for its black body and vivid red tail. It’s suitable as a tank mate for Oscar fish because it spends most of its time near the bottom of the tank where it can forage and hide in caves. Red-Tailed Shark grow to up to 6 inches in size.
The Bala Shark (Balantiocheilos melanopterus) is native to Southeast Asia and is known for its larger size and easygoing temperament. They are colored yellow, black, and gray, and they can grow up to 12 inches, in length making them relatively large for an aquarium fish. They’re suitable as tank mates for Oscar fish due to their large size and peaceful nature.
Black Ghost Knife Fish
The Black Ghost Knife Fish (Apteronotus albifrons) is a tropical fish belonging to the ghost knifefish family (Apteronotidae). They originate in freshwater habitats in South America where they range from Venezuela to the Paraguay – Paraná River, including the Amazon Basin. They’re suitable as tank mates for Oscar fish due to their large size and timid temperaments. Black Ghost Knife Fish grow to around 18-20 inches in size.
Chocolate Cichlid (Hypselecara temporalis) is a South American cichlid known for its colorations such as red, brown, orange, gold, green, and yellow. It’s relatively peaceful for a large cichlid and can be tank mates with a variety of cichlids and other fish. It’s suitable for Oscar fish because it shares similar water and food requirements. Chocolate Cichlid grow up to 12 inches in size.
Reedfish (Erpetoichthys calabaricus), also known as the ropefish or snakefish, this species is native to fresh and brackish waters in West and Central Africa. It has an eel-like body and possesses a pair of lungs in addition to gills. Reedfish are peaceful but carnivorous species that will consume swallowable tank mates. They are suitable tank mates for Oscar fish due to their size and non-aggressive nature. Reedfish grow to around 12-14 inches in size.
Banded Leporinus (Leporinus fasciatus) are known for its torpedo-shaped body with bold black and yellow bands running vertically down it. It’s native to the fast-flowing creeks and streams of the Amazon River basin. Banded Leporinus can grow pretty large up to 7 inches so it will not fit into the mouth of your Oscar Fish and will not get eaten.
This is a brightly colored exotic fish known for its unique hump on its head. Flowerhorns are artificially created hybrid fish that don’t exist in the wild. They are suitable tank mates for Oscar fish because they are similar in size, temperament, and water requirements. Flowerhorn grow to around 12 inches in size. Since both fish can be aggressive and territorial, it is important that adequate tank space is provided.
Peacock Bass (Cichla ocellaris), also known as Butterfly Peacock Bass, and Oscar fish can be kept together in the same tank, but there are a few important factors to consider. Peacock Bass are large, growing up to 29 inches in size. In addition, they can be aggressive. Therefore, a tank that is large enough to adequately house them all is required.
Remember, while these species may generally get along with Oscar fish, individual temperaments can vary, and compatibility can also depend on factors like tank size, tank setup, environmental conditions, and whether the fish were raised together from a young age.
Due to the Oscar’s size, tank requirements, aggression, and territorial behavior, not all fish are suitable as tank mates. In fact, there’s a lot of fish that will not be good tank mates for Oscar fish.
Here’s a list of unsuitable tank mates for Oscar fish:
- Angelfish: Freshwater angelfish and Oscar fish are both cichlids from the Amazon basin, and while it is technically possible for them to coexist in the same tank, it’s generally not recommended. Both fish are territorial, and it will most likely create a hostile environment. With that said, angelfish are much smaller and more delicate compared to the robust Oscar fish. If they are placed in the same tank, it is possible that the angelfish may not survive.
- Koi: Koi are a type of carp that are bred for their large size and variety of colors. They originated in Japan and other parts of eastern Asia and are often kept as ornamental fish in ponds. However, Koi and Oscar fish have different environmental needs and temperaments, making them incompatible as tank mates.
- Goldfish: Full grown goldfish can be quite large. At its full adult size, it would be too large for them to get eaten by Oscar fish. However, since goldfish and Oscar fish have have different environmental needs and temperaments, they are not compatible as tank mates.
- Betta Fish (Siamese Fighters): Betta fish, also known as Siamese fighting fish, are very popuare very popular fish in the aquarium hobby. They only grow to around 2.5 inches, making them too small to be tank mates with Oscar fish.
- Tetras: Tetras are a group of freshwater fish with over 150 different types. In general, they are small, lively, hardy, and unaggressive. Tetras are generally not good tank mates for Oscar fish because they are simply too small. There’s a high chance that they will get eaten by the Oscar.
- Cory Catfish: Cory catfish are small, bottom-dwelling freshwater fish that belong to the Corydoras genus. They are known for their peaceful nature and active behavior. They are not suitable tank mates for Oscar fish because Oscars are large, aggressive, and may view smaller fish like Cory catfish as food.
- Livebearers (mollies, guppies, platies, swordtails): Livebearers are a group of fish that includes mollies, guppies, platies, and swordtails. They are called livebearers because the females retain their eggs until they are fully developed and give birth to free-swimming fry. They are not suitable tank mates for Oscar fish because of their small size. Oscars may view them as food due to their large size and aggressive nature.
- Dwarf Gourami: Dwarf Gouramis are small freshwater fish known for their bright colors and unique appearance. They grow up to 3 inches long and have a peaceful temperament. They are not suitable tank mates for Oscar fish because Oscars may view them as food due to their large size and aggressive nature.
- Rasboras: Rasboras are small, colorful, schooling fish from the Cyprinidae family. They are active and generally slender with a protruding lower jaw. They are not suitable tank mates for Oscar fish because of their small size. Oscars may view them as food due to their large size and aggressive nature.
- Danios: Danios are members of the large Cyprinidae or minnow family. They are omnivorous and feed primarily on zooplankton, phytoplankton (including algae), small insects, and larvae. They are tolerant of a wide range of habitats and water conditions. However, the vast majority of danio species are not suitable tank mates for Oscar fish because Danios are too small. Oscars may see Danios as food due to their small size.
- Kuhli loaches: Kuhli loaches are eel-shaped fish with slightly compressed sides, four pairs of barbels around the mouth, and very small fins. They are bottom dwellers that burrow into soft places. They are not suitable tank mates for Oscar fish because Kuhli loaches are too small.
- Discus: Discus fish, also known as Symphysodon, is a genus of cichlids native to the Amazon river basin in South America. They have a distinctive shape, behavior, and bright colors and patterns. They are not suitable tank mates for Oscar fish because Discus fish are very shy and gentle while Oscar fish are aggressive species.
- Cherry Shrimp: Cherry Shrimp (Neocaridina davidi) are small freshwater shrimp that originated from Taiwan. They are fascinating invertebrates that help keep the fish tank clean. However, they are not suitable as Oscar tank mates because they are too small.
- Snails: Aquarium snails and Oscar fish are not suitable tank mates. There’s a high chance that the Oscars will eat the snails fairly quickly.
- Crayfish: Crayfish and Oscars are not compatible as tank mates. There’s a high chance that the Oscars will eat the crayfish fairly quickly.
Keep in mind that this is a general guideline of expected behaviors of fish. Even if they are of the same species, some fish will behave differently than others. Therefore, close observation and careful monitoring is important.
Oscar fish do not necessarily need tank mates. They can be kept in a solitary tank. However, they may get lonely, so having tank mates could be good.
With that said, tank mates should be selected with careful consideration, and made sure they are compatible. They must be compatible in terms of their size, temperament, and habitat.
Next, it’s important to make sure there’s enough space to accommodate the Oscar and the tank mates. Oscars are large and territorial. Therefore, if there’s not enough space in the tank, it’s better not to add any tank mates.
Oscar fish are known to be aggressive. However, some levels of aggression are not always bad, as long as it can be managed. Some behaviors such as jaw-locking, lip-locking, and chasing may occur occasionally. The key is to prevent overly aggressive behavior that may cause harm to them or their tank mates. In order to do so, it’s important to understand and address the root cause of their aggression.
Here are some causes of Oscars’ aggression:
- Territorial Instincts: Oscars are territorial fish, and they often claim their own space within the tank. If any other fish enter their territory, they get aggressive and chase them out. Aggression derived from territorial instincts can be managed by placing them in a tank of adequate size.
- Establish Dominance: Oscars can show aggression when they are trying to establish dominance. In most cases, once the hierarchy is established by the dominant fish, the levels of aggression can go down. However, if there’s not enough space in the tank, the dominant fish can continue bullying the weaker fish. Therefore, proper tank size and adequate hiding places would be important.
- Breeding Season: Breeding season can increase the levels of aggression. While providing adequate tank space is important, separating the breeding pair may be necessary if the level of aggression can not be managed. If you intend to breed Oscars successfully, providing a separate breeding tank would be recommended.
- Aggression from Hunger: Fish can get aggressive when they are hungry. This may be caused by their perceived need to compete for resources. By keeping the fish well fed, levels of aggression may be managed.
- Incompatible Tank Mates: If Oscars are placed in the same tank with incompatible tank mates, levels of aggression may increase. Incompatible tank mates would include fish that are too small or too fragile, and these fish may result in the Oscars constantly bullying it.
- Lack of Space: If there’s not enough tank space, it will almost always lead to aggression. The fish will be constantly stressed, and may lead to unnecessary aggression. Providing adequate tank size is very important.
- Visibility: If the fish are constantly looking at each other, it can lead to more aggression. Hardscapes, decor, and plants can help break the line of sight, which may help reduce the frequency of aggressive behavior.
While entirely avoiding aggression in Oscars may not be possible, managing aggression would be the goal. This is important because overly aggressive Oscars that are left unchecked may end up harming or killing their tank mates. With careful observation and preventative measures, overly aggressive behavior can be avoided in most cases.
It’s possible to keep many Oscars in a tank, and the number you can keep depends primarily on the tank size. As a general guideline, you can keep one Oscar in a 55 gallon tank, and add 20-30 gallons of water for each additional Oscar.
With that said, keeping three Oscars in a tight space can cause problems if a pair is formed within the three. The pair would bond together, but the third fish may be pushed to the corner. This may cause issues, especially during breeding season.
Not all species of Cichlids are suitable as tank mates for Oscars, but many are. This is no surprise since Oscars are actually a type of Cichlid. Oscars are a species of South American Cichlid.
There are over 1300 species of Cichlids, but the vast majority are categorized as African Cichlid, South American Cichlid, or Central American Cichlid.