Compatibility brief
Can American Flagfish live with Guppy?
Caution. Check the issues below before buying.
American Flagfish + Guppy: Temperament difference. American Flagfish is semi-aggressive, while Guppy is peaceful. 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.
60L
Combined minimum footprint reference for these two species: about 60L (larger active fish often want more length).
American Flagfish is a fin nipper and Guppy is vulnerable to nipping — long fins are a common target even when water parameters match.
Assessment details
Temperament difference
Top issueAmerican Flagfish is semi-aggressive, while Guppy is peaceful. This can work with adequate space and hiding spots, but monitor for bullying.
Fin nipping risk
American Flagfish is a known fin nipper and Guppy has long, flowing fins. American Flagfish will likely harass Guppy.
Compatible temperature range
Both fish can comfortably share similar water temperatures.
“American Flagfish is semi-aggressive, while Guppy is peaceful”
Temperament difference
Next steps
Concrete changes, not "research more" filler.
- •Provide plenty of hiding spots and visual breaks so Guppy can escape if harassed.
- •Avoid keeping American Flagfish with long-finned fish like Guppy.
Try instead
- →Provide plenty of hiding spots and visual breaks so Guppy can escape if harassed.
- →Avoid keeping American Flagfish with long-finned fish like Guppy.
- Seriously Fish. Jordanella floridae
Primary: species page covering Florida range, temperate temperature tolerance, hair-algae diet, and the strong male territoriality at spawning.
- Aquarium Co-Op. American Flagfish Care
Secondary: retailer guide on the algae-eating role and the long-fin warning.
- Seriously Fish. Poecilia reticulata
Primary: aquarium size, water chemistry, behaviour, and compatibility (URL verified in upgrade script; recheck if site content changes).
- FishBase. Poecilia reticulata
Secondary: taxonomy, distribution, and maximum length in nature; cross-check with aquarium import lines and measured tank parameters.
- Wikipedia. Poecilia reticulata
Secondary: general species context; verify all husbandry numbers against a dedicated aquarium care sheet and your test kit, not a single table row.
- Wikipedia. Guppy
Encyclopaedia overview; use specialist aquarium sources for your stock's real temperature/pH/footprint needs.
Try this next
Build the full stocking list with American Flagfish + Guppy
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 (American Flagfish): Based on typical aquarium care sources; details may vary between setups.