Compatibility brief
Can Apistogramma Macmasteri live with Oscar?
Risky. This mix is commonly discouraged for typical setups.
Compatibility score
Profile confidence: medium
How we decideFishori checks adult size and predation risk, behaviour, water requirements and tank needs before giving a verdict.
300L
Combined minimum footprint reference for these two species: about 300L (larger active fish often want more length).
Oscar (about 35cm as an adult) can realistically eat Apistogramma Macmasteri (about 7cm) once grown. Plan around adult sizes, not shop sizes.
Temperament gap (semi-aggressive vs aggressive) adds stress on top of the hard incompatibility — space and cover do not make this pairing safe.
Assessment details
Temperament difference
Oscar is aggressive, while Apistogramma Macmasteri is semi-aggressive. Expect chasing or stress unless the tank is large and heavily structured — monitor closely.
Oscar may eat Apistogramma Macmasteri
Top issueOscar (35cm) is predatory and Apistogramma Macmasteri (7cm) is small enough to be eaten. This pairing is unsafe.
Compatible temperature range
Both fish can comfortably share similar water temperatures.
“Oscar (35cm) is predatory and Apistogramma Macmasteri (7cm)…”
Oscar may eat Apistogramma Macmasteri
Next steps
Concrete changes, not "research more" filler.
- •Provide plenty of hiding spots and visual breaks so Apistogramma Macmasteri can escape if harassed.
- •Oscar reaches ~35cm: tank length and turning room matter more than the litre number. A tall, short tank of the same volume is not equivalent.
Try instead
- →Build a species-only tank for the larger fish, or restock with fish too large to be eaten at adult sizes.
- Seriously Fish. Apistogramma macmasteri
Primary: species page covering Meta basin habitat, soft acidic water requirement, and the strong territorial behaviour at spawning sites.
- Practical Fishkeeping. Macmaster's Apistogramma
Secondary: editor coverage of colour variants (gold, red-mask) and the strong line-breeding of the species in the hobby.
- 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.
Try this next
Build the full stocking list with Apistogramma Macmasteri + Oscar
Plan further
Check each species’ mates list, size the glass, then verify the full stock in the builder. 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: high. Checked against several solid care sources that mostly agree.