Should I buy it?
Serpae Tetra
Hyphessobrycon eques
Also known as: jewel tetra, Jewel tetra
Fishori provides conservative planning guidance, not guarantees.
Based on multiple reputable aquarium care sources with strong agreement. Use the numbers here as planning defaults — your room, water, and routine still shape real-world outcomes.
A notorious fin-nipper that needs a large group to redirect aggression inward. A school of twelve in the right tank is beautiful; fewer creates a fin-shredding problem.
Best for
Species-specific tanks or planted tanks 100L or more with ten or more serpae and no long-finned companions.
Avoid if
You keep bettas, angels, guppies, or any long-finned fish. Any community tank with fewer than ten serpae.
Top things that go wrong
- Fin-nipping risk in typical community layouts. Fin-nipping risk toward long-finned or slow tank mates when the school is understocked, bored, or kept in a tank too short to spread out in.
- Group welfare — not a solo display fish. Plan at least **8** together for normal behaviour; smaller groups often mean stress, colour loss, or nipping depending on species.
- Shrimp & snails. Shrimp: depends on the individual fish. Some leave them alone, others hunt cherry shrimp down within a week of meeting them.
Common mistakeThree serpae tetras in a community tank. Small groups produce focused relentless fin nipping on long-finned neighbours.
What most shops don't tell you
- 1.Fin nipping can appear when the group is too small, the tank is too short, or fish are bored. Fix structure and numbers, not just water changes.
- 2.Buying three or four to start. Serpae Tetra settles in a group of 8 or more. An understocked school sulks at the back of the tank and loses colour within a fortnight.
- 3.Eight or more in a long planted tank. No guppies or bettas in the mix. Serpaes are not a safe default community fish; they nip long fins when bored.
- 4.Serpae tetras can nip long fins when understocked or bored — large schools and no long-finned tank mates.
About this species
Serpaes are red-finned tetras that nip long fins when the school is small or the tank is short. A bigger school in a long tank reduces nipping. Still a poor match for slow long-finned fish.
- Black phantom tetra80L min · same group, comparable tank size
- Columbian Tetra80L min · same group, comparable tank size
- Diamond Tetra120L min · same group, comparable tank size
- Penguin tetra80L min · same group, comparable tank size
- Rosy Tetra80L min · same group, comparable tank size
- Rummy Nose Tetra80L min · same group, comparable tank size
- Splash tetra80L min · same group, comparable tank size
- Beckford Pencilfish60L min · same group, similar adult size
- Agassiz’s dwarf cichlidalso intermediate semi-aggressive, similar tank size
- American Flagfishalso intermediate semi-aggressive, similar tank size
- Angelfishalso intermediate semi-aggressive, similar tank size
- Apistogramma Borelliialso intermediate semi-aggressive, similar tank size
- Apistogramma Macmasterialso intermediate semi-aggressive, similar tank size
- Apistogramma Trifasciataalso intermediate semi-aggressive, similar tank size
No reverse lookups on file yet.
Plan grid
Key limits are shown above; this section adds planning detail: pH band, swim level, bioload and activity, and the radar.
Swim zones
Planning trait chart
Six indices for comparing species on paper before you spend.
- Beginner ease38
- Peacefulness30
- Community fit22
- Small-tank fit100
- Hardiness54
- Energy86
Numbers are deterministic planning indices from Fishori fields — not a scientific score of your individual fish.
Common setup sketches
Conservative patterns from Fishori fields — still run the pair checker for every species you add; sketches are not a stocking guarantee.
Prioritise 8+ of Serpae Tetra in 100L+ with filtration sized for messy feeding — add only mates that already pass pair checks with this species.
Tank mate intelligence
Use the "Often compatible" lists as a shortlist, not a stocking plan. Always run the pair tool and check the footprint of your actual tank first. Verify behaviour for Serpae Tetra against your own reading before you buy.
Pair-level compatibility with this fish as anchor.
Read the blocking rule on each pair page before experimenting.
Do-not-stock combinations on conservative hobby rules.
Compare with
Run a real pair check: Serpae Tetra + Corydoras Catfish
Behaviour, temperament, and what to watch
Prose and lists come from the same record: read temperament first, then glass-level signals so you are not surprised after day three.
Serpae Tetra is semi-aggressive: stable in a calm tank, pushy with weaker fish when stressed or crowded. Fin-nipper when the school is understocked, bored, or kept in a tank too short to spread out in.
Stress / aggression triggers on file
- Small groups or boredom
- Long-finned or slow tank mates
- Bare tanks without structure
Fin nipping: Fin-nipping risk toward long-finned or slow tank mates when the school is understocked, bored, or kept in a tank too short to spread out in.
Predation: Not a predator toward similarly-sized community fish. The usual community caveats about mouth size still apply for very small fry or shrimp.
Territory: Not strongly territorial, but still claims a working area in the tank. Give it room to settle without overlapping the next species' patch.
Planted tanks: good — easy plant ideas
In the glass: typical and warning signs
- Busy at feeding time — expects food to hit the water predictably.
- Shoaling/schooling: most colour and confidence show when the group meets **8+**.
- Clamped fins, gasping at the surface, hiding non-stop, or refusing food after the first week.
- Rapid breathing when parameters swing — fix ammonia/nitrite first, then reassess mates.
- Chasing one individual repeatedly, torn fins on tank mates, or food theft every feed.
- Separate or rehome if injuries appear, one fish is pinned, or feeding becomes a daily chase.
- If water is stable but behaviour worsens, reduce stocking or remove the highest-impact species first.
Fish behaviour can vary between individuals and tank setups. Always observe new fish closely after introduction.
Care parameters: water, food, inverts, grouping
Chemistry and group rules sit here so you are not re-reading the same line from tank mate or temperament blocks. Swim level is in the plan grid above.
Hardness
soft
Diet
omnivore
Mixed diet: a quality flake or pellet as the staple, with frozen or live foods two or three times a week.
Shrimp & snails
Shrimp: depends on the individual fish. Some leave them alone, others hunt cherry shrimp down within a week of meeting them.
Shoaling species. Buy 8 or more of one species together. Smaller schools sulk, lose colour, and redirect their schooling energy at whatever else is in the tank.
Egg scatterers and schoolers still spawn in stable tanks. Have a plan for the fry, or accept that the parents and tank mates will eat them in a community setup.
- Hold 22 to 28 °C steadily on a real thermometer, not the dial on the heater.
- Aim for pH 5 to 7.5 and a hardness you can re-test in two weeks. A one-time strip in the shop car park is not a water test.
- Schooling species. Buy 8 or more from the same tank on the same day before adding any centrepiece fish.
- Tank volume meets or exceeds 100L published minimum for adults.
- You can stock at least 8 individuals (group welfare).
- Heater can hold 22–28°C without cooking cooler-water tank mates.
- No known fin-nippers paired with long-finned fish unless you accept documented risk.
Explore and stocking hubs
Same library as the rest of Fishori: tank-mate index for this species, category peers, guides, and litre-based stocking lists where min tank on file is within the hub volume.
Plan with tools
Pair-level rules and multi-fish stocking use the same conservative engine — add this fish in the tank builder only after mates pass pair checks.
Filtration & heating
A 100L minimum tank needs a filter rated for at least 400L/hr turnover and a heater to hold 22–28°C reliably.
Plant suggestions
Serpae Tetra does well in planted tanks. Plants compatible with 22–28°C and pH 5–7.5:
Profile status: partially verified · Evidence tier: high · 3 linked source(s). Fishori does not fabricate citations.
Fishori uses conservative planning rules based on these sources.
Confidence is explained in the summary at the top of this page (same tier as here), not repeated below.
How Fishori evaluates compatibility (same logic as pair and tank tools).
- Seriously Fish. Hyphessobrycon eques
Primary: aquarium size, water chemistry, behaviour, and compatibility (URL verified in upgrade script; recheck if site content changes).
- FishBase. Hyphessobrycon eques
Secondary: taxonomy, distribution, and maximum length in nature; cross-check with aquarium import lines and measured tank parameters.
- Wikipedia. Hyphessobrycon eques
Secondary: general species context; verify all husbandry numbers against a dedicated aquarium care sheet and your test kit, not a single table row.
Evidence notes
- The Seriously Fish profile for the binomial in this record was successfully reached as the primary aquarium reference.
- FishBase contributes natural-range size and habitat context. Translate those numbers through your heater, your water report, and your tank footprint before stocking.
- Wikipedia is only cited if the article URL returned OK. Use it for orientation, not as the only care sheet for an import.
- All compatibility text reflects typical hobby experience and the Fishori model. Individual fish, shop stress, and the order tank mates are added in can still defy a single-paragraph label.
- Fishori profiles work from typical aquarium trade sizes and hobby care norms. Specialist site checks and literature review for this species are not yet recorded here, so the ranges on this page are planning numbers rather than guarantees.