Compatibility brief
Can Oscar live with Severum?
Caution. Check the issues below before buying.
Oscar + Severum: Temperament difference. Oscar is aggressive, while Severum is semi-aggressive. This can work with adequate space and hiding spots, but monitor for bullying. Outcomes still depend on your tank shape, maintenance routine, and individual fish.
Compatibility score
Profile confidence: low
Order of checkstank volume vs adults → predation mouth gap → temperament / fin nipping → shared water windows.
300L
Combined minimum footprint reference for these two species: about 300L (larger active fish often want more length).
Temperament gap (aggressive vs semi-aggressive) — can work with space, structure, and careful observation, but not a “drop and forget” mix.
Assessment details
Compatible temperature range
Both fish can comfortably share similar water temperatures.
“Oscar is aggressive, while Severum is semi-aggressive”
Temperament difference
Next steps
Concrete changes, not "research more" filler.
- •Provide plenty of hiding spots and visual breaks so Severum can escape if harassed.
Try instead
- →Provide plenty of hiding spots and visual breaks so Severum can escape if harassed.
- Seriously Fish. Astronotus ocellatus
Primary: aquarium size, water chemistry, behaviour, and compatibility (URL verified in upgrade script; recheck if site content changes).
- FishBase. Astronotus ocellatus
Secondary: taxonomy, distribution, and maximum length in nature; cross-check with aquarium import lines and measured tank parameters.
- Wikipedia. Astronotus ocellatus
Secondary: general species context; verify all husbandry numbers against a dedicated aquarium care sheet and your test kit, not a single table row.
- Wikipedia. Astronotus ocellatus (oscar)
Encyclopaedia overview; use specialist aquarium sources for your stock's real temperature/pH/footprint needs.
- Seriously Fish. Heros efasciatus (striped / gold ‘severum’ in trade, primary care proxy)
Primary: aquarium size, water chemistry, behaviour, and community context for a Heros sp. with strong hobby coverage. Most tank-bred 'severums' in shops are this species or man-made colour lines close to it; compare with a true Heros severus (below) for breeding biology and colour.
- Practical Fishkeeping. Frequently asked questions on South American cichlids
Primary: editorial Q&A on South American cichlid communities; mentions severums in mixed-tank and compatibility thinking. Still not a one-page Heros severus monograph.
- FishBase. Heros severus
Secondary: formal species account for the binomial used in this record; the trade and Singapore farm lines often do not match wild-type severus, so this is a taxonomy anchor, not a guarantee your fish is a pure H. severus.
Try this next
Build the full stocking list with Oscar + Severum
Plan further
Try both species in the full-stock tank check, or open either fish profile for mates lists. Methodology explains how verdicts are produced.
Individual fish vary in personality. Fishori uses conservative hobby rules. Observe any new introduction closely, feed thoughtfully, and keep a quarantine or backup plan. This is not veterinary advice.
Profile data confidence: medium. Driven by the lower-confidence profile (Severum): Based on typical aquarium care sources; trade names can be ambiguous, so details may vary between setups.

