Can Oscar Fish And Severums Live Together?

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I have to admit, both Oscar fish and Severums are absolutely captivating and visually stunning aquatic creatures.

Now, here’s the real question: Is it possible to keep them together in the same tank? What factors should you keep in mind?

In this article, I will tackle these questions and provide some essential tips on how to keep the two species together successfully. Let’s get started.

Can I Keep Oscar Fish And Severums Together In The Same Tank?

Yes, Oscar fish and Severum are compatible tank mates. However, their compatibility is contingent on several factors. Delving into this:

  • Aggression Spectrum: Oscar fish are inherently more aggressive than Severums. While both can coexist, it’s vital to understand the inherent nature of Oscars to ensure the Severum’s safety.
  • Size Disparity: Oscars can grow up to 12-14 inches, whereas Severums can reach 8-10 inches. Their size difference can sometimes influence dominance, with the Oscar fish typically asserting itself more.
  • Territorial Behavior: While Severums are more peaceful, they still establish territories within the tank. Introducing Oscar fish to a pre-established Severum territory might lead to disputes.
  • Activity Levels: Oscar fish are more active and might sometimes intrude or disturb the more placid Severum, potentially causing stress to the latter.
  • Individual Variance: It’s crucial to remember that individual personalities can differ. Some Oscar fish might be more docile, while others more assertive, and the same goes for Severums.

Also Read: 19 Great Oscar Fish Tank Mates

Oscar Fish vs. Severum: Behavior

The first factor worth considering is the Oscars’ and Severum’s natural behavior. Here is what you should know:

Oscar Fish: Natural Behavior

Oscar fish are notorious for their vibrant personalities and their aggressive, territorial nature. 

Native to the Amazon River Basin, their behavior has evolved to be dominant and assertive, often displaying a ‘bossy’ attitude in the aquatic environment. Here’s an in-depth look:

  • Territorial Dominance: Oscar fish frequently establish territories within the aquarium. They can be seen chasing off other fish that come too close to their claimed area.
  • High Activity Levels: Oscars are energetic swimmers and curious explorers. Their movements are often rapid, especially when hunting or asserting dominance.
  • Aggressive Displays: When threatened or challenging another fish, Oscar fish may flare their gills and open their mouths wide as an intimidation tactic.
  • Dietary Eagerness: Oscar fish are voracious eaters. They will quickly go after food, often eating a wide variety of prey, including smaller fish, crustaceans, and insects.
  • Mood Indicators: Oscar fish can change color based on their mood or health. A stressed or sick Oscar might appear more pale, while a healthy and vibrant one will display brighter colors.

Severum: Natural Behavior

Severums, in contrast to the boisterous Oscar fish, are generally peaceful and more community-oriented.

Originating from the same Amazonian waters, their demeanor is notably more laid-back, making them less aggressive tank mates. Diving deeper:

  • Peaceful Coexistence: Severums typically prefer to live harmoniously with other fish. They are less likely to initiate confrontations compared to the Oscar fish.
  • Subdued Territoriality: While they do establish territories, Severum’s claims are less aggressively defended. Their approach to territory is often more passive.
  • Social Interactions: Severums often display social behaviors, especially during breeding. They form pairs and can be seen engaging in communal activities.
  • Varied Diet: Like Oscar fish, Severums are omnivores. However, their feeding habits are less aggressive, often grazing on algae or nibbling on soft plants, in addition to consuming pellets or small prey.
  • Subtle Communication: Severums might display subtle color changes or body movements to communicate. While less dramatic than Oscar fish displays, it’s a significant aspect of their behavior.

Ideal Parameters For Oscar Fish And Severums

When establishing a tank for both Oscar fish and Severum, one must be mindful of the distinct requirements each species demands.

The table below presents an overview of the ideal parameters for each, alongside suggestions for tanks housing both fish types:

ParameterOscar FishSeverumBoth Types
Temperature74°F to 81°F72°F to 84°F74°F to 84°F
pH Level 6.0 to 8.06.0 to 7.56.0 to 8.0
Water Hardness Soft to moderately hardSoft to mediumSoft to moderately hard

Oscar Fish: Ideal Parameters

Oscar fish thrive when they are provided with water conditions similar to their natural Amazonian habitat.

Ensuring optimal water parameters not only promotes the health of the Oscar fish but also their vibrant coloration and natural behavior.

A breakdown of these parameters includes:

  • Temperature: Oscar fish prefer a warmer aquatic environment. The ideal temperature range for them is between 74°F to 81°F (23°C to 27°C).
  • pH Level: Oscars thrive in slightly acidic to neutral water. The optimal pH level for Oscar fish is between 6.0 to 8.0.
  • Water Hardness: Oscar fish aren’t particularly sensitive to hardness. However, a general hardness (GH) of 5 to 20 dGH is suitable for their well-being.

Severum: Ideal Parameters

Severums, also native to the Amazon River Basin, have water requirements that largely overlap with the Oscar fish.

However, there are subtle differences in the ideal parameters for Severums that can make all the difference in their health and vitality.

Here’s a detailed look:

  • Temperature: Severums enjoy slightly varied temperatures compared to Oscar fish. The recommended range is between 72°F to 84°F (22°C to 29°C).
  • pH Level: Much like the Oscar fish, Severums do well in slightly acidic to neutral water. A pH range of 6.0 to 7.5 is ideal for them.
  • Water Hardness: For Severums, a softer water environment is preferred. A general hardness of 4 to 15 dGH will ensure their comfort.

Oscar Fish vs. Severum: Tank Setup

To keep Oscar fish and Severum together, their distinct tank setup preferences should be harmoniously merged.

The table below contrasts their needs and offers recommendations for a combined environment:

Setup AspectOscar FishSeverumBoth Types
Ammonia, Nitrite & Nitrate 0 ammonia, 0 nitrite, <40 ppm nitrate0 ammonia, 0 nitrite, <40 ppm nitrate0 ammonia, 0 nitrite, <40 ppm nitrate
Tank SizeMinimum 55 gallons40-50 gallonsAt least 100 gallons
FoliageSturdy plants like Java fernBroad-leaved plantsVariety of sturdy and broad-leaved plants
DecorationsCaves, rocks, driftwoodDriftwood, caves, rocksMix of caves, rocks, driftwood
FilterPowerful external filterGood quality external filterPowerful external filter
SaltBeneficial in small amountsRarely neededUse cautiously
PumpGood water circulationModerate circulationStrong circulation
LightingModerate with day-night cycleSubdued with day-night cycleModerate with day-night cycle

Oscar Fish: Tank Setup

Oscar fish are popular in the aquarium trade for their personality and beauty, but their robust nature requires a specific setup for optimum health.

Ensuring that their environment mimics their natural habitat in the Amazon will guarantee they display their vibrant behaviors and maintain optimal health.

Delving into the ideal setup:

  • Ammonia, Nitrite & Nitrate: Oscars produce a significant amount of waste. Ensure a zero reading for ammonia and nitrite, and keep nitrate levels below 40 ppm.
  • Tank Size: Oscar fish grow large, often reaching 12-14 inches. A minimum tank size of 55 gallons for a single Oscar is recommended, but larger is better.
  • Foliage: While Oscar fish may occasionally uproot plants, sturdy plants like Java fern can be integrated.
  • Decorations: Oscars appreciate hiding spots. Caves, large rocks, and driftwood can be beneficial additions.
  • Filter: Due to their size and waste output, a powerful external filter is necessary to maintain clean water for Oscar fish.
  • Heater: Oscars thrive in warmer temperatures. A reliable heater maintaining a temperature between 74°F to 81°F is ideal.
  • Salt: Adding aquarium salt in small amounts can be beneficial for Oscar fish, aiding in stress reduction and preventing certain diseases.
  • Pump: A good water circulation pump helps in oxygenating the water, which Oscar fish appreciate.
  • Lighting: Moderate lighting simulates the Oscar’s natural habitat, and a regular day-night cycle should be maintained.

Severum: Tank Setup

Severums, with their peaceful disposition and vibrant colors, need a slightly different environment from Oscars despite their similar Amazonian origins.

Their tank setup should prioritize a natural and calm setting for them to display their best behaviors.

Here’s the breakdown:

  • Ammonia, Nitrite & Nitrate: Like most fish, Severums thrive in a tank with zero ammonia and nitrite. Keep nitrate levels under 40 ppm for their health.
  • Tank Size: Severums can grow up to 8-10 inches. A 40-50 gallon tank is suitable for a single Severum, but bigger tanks allow for more natural behavior.
  • Foliage: Severums do well with a mix of plants, especially broad-leaved ones which they sometimes use for breeding.
  • Decorations: Provide hiding spots using driftwood, caves, and rock formations to mimic their natural habitat.
  • Filter: A good quality external filter ensures clean water, crucial for the Severum’s health and vibrant coloration.
  • Heater: Severums need temperatures between 72°F to 84°F, so a consistent heater is necessary.
  • Salt: Unlike Oscar fish, Severums don’t typically require aquarium salt. Use only if recommended for specific health issues.
  • Pump: A moderate water circulation pump aids in keeping the water oxygen-rich, beneficial for Severums.
  • Lighting: A more subdued lighting setup replicates the Severum’s natural environment, and a day-night cycle is recommended.

The Dietary Requirements Of Oscar Fish And Severums

While Oscar fish and Severum have different dietary leanings, they both require a mix of nutrients to thrive.

This table illustrates their feeding necessities and offers a composite approach when catering to both:

Diet AspectOscar FishSeverumBoth Types
Food TypesMeaty foods, pellets, or sticksPellets, flakes, brine shrimp, chopped vegetablesVariety of both diets, balanced for each
QuantityAmount consumed within 2-3 minutes Amount consumed within 2-3 minutes Adjusted amount for both types, monitor closely
Feeding ScheduleOnce or twice dailyOnce or twice dailyOnce or twice daily, separate feeding if possible

Oscar Fish: Ideal Dietary Requirements

Oscar fish are known for their voracious appetite and require a varied diet to ensure their health and vibrant coloration.

Being carnivorous by nature, they thrive on a protein-rich diet that mimics the prey they would hunt in the wild. Focusing on their dietary specifics:

  • Food Types: Oscars primarily thrive on meaty foods. Live or frozen varieties such as shrimp, crayfish, and small fish, along with high-quality pellets or sticks, are ideal.
  • Quantity: Oscar fish eat heartily, but overfeeding should be avoided. Typically, offer an amount they can consume within 2-3 minutes, ensuring no food goes uneaten.
  • Feeding Schedule: It’s best to feed Oscar fish once or twice daily. Consistency is crucial for their metabolic health and overall well-being.

Severum: Ideal Dietary Requirements

Severums, unlike the carnivorous Oscar fish, are omnivores, which means they have a more varied diet encompassing both plant and animal matter.

A balanced diet for Severums is essential to maintain their health and bring out their beautiful colors. Diving into their dietary needs:

  • Food Types: Being omnivores, Severums enjoy a mix of vegetable matter and protein. Offer them a combination of high-quality pellets, flakes, live or frozen brine shrimp, and finely chopped vegetables.
  • Quantity: Like Oscar fish, Severums should only be given the amount they can eat within 2-3 minutes, ensuring no excess waste.
  • Feeding Schedule: Feeding Severums once or twice a day provides them with the nutrition they need. It’s essential to maintain a consistent schedule for their overall health.

Guidelines for Housing Oscar Fish and Severums Together

Both Oscar fish and Severum hail from the Amazon Basin, but each has unique behaviors and necessities.

To maintain a peaceful coexistence, it’s crucial to focus on their tank environment, setting, and behavior patterns. Here are some recommendations for a harmonious tank:

  • Tank Proportions are Key: Oscars, being larger and territorial, necessitate at least a 100-gallon tank to sufficiently accommodate both species.
  • Designate Territories: Oscars have a strong sense of territory. Incorporate elements like rocks, driftwood, and plants to form clear boundaries, decreasing potential conflicts.
  • Keep an Eye on Aggressiveness: Oscars are generally the dominant ones, but Severums can be territorial too. Monitor their behavior closely and intervene if required.
  • Dietary Needs: It’s vital that both species get their respective diets. Oscars lean towards protein, while Severums benefit from a blend of plant and animal content.
  • Avoid Overstocking: Maintaining an ideal number of fish lessens strain. Overpopulation might amplify Oscar’s aggression and unsettle the Severum.
  • Prioritize Water Standards: Regularly check water conditions such as pH and temperature, ensuring they align with the requirements of both fish.
  • Be Extra Observant During Mating Seasons: Both fish can become extra territorial when breeding. Monitor for heightened aggression, possibly separating them if mating happens.

Ideal Tank Companions for Oscar Fish and Severums

When introducing other species to a tank housing Oscar fish or Severum, select companions that match in size, behavior, and habitat requirements.

While both Oscar fish and Severum are assertive, certain species can peacefully share their space. To promote a balanced tank environment, consider the following companions:

  • Plecostomus: Commonly referred to as “Plecos”, these resilient fish can tolerate Oscars. Being bottom-feeders, they generally avoid direct confrontations.
  • Jack Dempsey: Comparable in size and nature to Oscars, Jack Dempseys can stand their ground but still require occasional behavioral checks.
  • Silver Dollars: These amiable, fast-moving fish can dodge potential Oscar confrontations and bring dynamism to the middle tank layer.
  • Firemouth Cichlids: These petite cichlids pair well with Severums given their alike personalities. Yet, they might need extra attention around the heftier Oscar fish.
  • Convict Cichlids: They may be smaller, but their resilience allows them to live harmoniously with both Oscars and Severums, particularly in expansive tanks with well-defined territories.

Also Read: Can Oscar Fish And Convict Cichlids Live Together?


For those skimming through, here’s a concise version of the above insights:

  • Oscar fish and Severum can peacefully share a space if their unique behaviors are recognized and accommodated.
  • Although Oscars tend to be more dominant, proper tank size and tailored diets can ease coexistence.
  • Sustaining the right water conditions for each species is paramount.
  • A thoughtful tank layout, feeding practices, and regular observation aid in their peaceful living.
  • For a harmonious setting, grasp their characteristics, provide suitable surroundings, and stand ready to act if tensions flare up.