Should I buy it?
Opaline gourami
Trichopodus trichopterus
Also known as: three spot gourami (colour form)
A large semi-aggressive gourami at 15 cm with blue-green marble patterning. Males fight other gouramis and harass slower community fish.
Opaline gourami tank mates · 160L tank size hub
semi-aggressive · intermediate care
Sources & confidencehigh · partially verified · beginner: caution
Checked against several solid care sources that mostly agree. Numbers here are a careful starting point. Your tap water, tank size, and habits decide the rest. How we evaluate.
Best for: Community tanks 150L or more with a single male as centrepiece and mid-size robust companions.
Avoid if: You keep multiple gouramis, small or slow-moving fish, or bettas.
Common mistakeHousing two male opaline gouramis in one tank because the colour looked good in the shop is how keepers invent a permanently beaten fish. Males fight until one stops eating. Keep a single male as the centrepiece, or give a true pair and a large planted footprint with broken sight lines — not a second male “for company.”
Top things that go wrong
- Fin-nipping risk in typical community layouts. Will nip long fins or slow fish when the school is too small, bored, or kept in a short tank.
- Mouth gap vs tiny tank mates. May eat tank mates small enough to fit the adult mouth — plan adult sizes, not shop sizes.
- Shrimp & snails. Not shrimp-safe — adults, fry, or both get eaten.
What most shops don't tell you
- 1.Shops sell opaline gouramis as peaceful blue community fish for any planted tank. Adults near 15 cm claim the midwater, nip slower fins, and can take very small fish. Peaceful on a juvenile label is not the same as nano-safe next to a male betta.
- 2.Mixed with bettas or honey gouramis in short shallow tanks with no escape routes.
- 3.Underfed on protein only, which can sharpen fin-nipping on tank mates at feeding time.
- 4.Give line-of-sight breaks and a footprint that matches an adult 12-15 cm gourami. Do not keep two males in small aquaria without clear territory.
About this species
Three-spot gourami colour morph that reaches 15 cm. Can be assertive in small or under-furnished tanks, and males chase long-finned or very small fish.
- Moonlight gourami180L min · same group, comparable tank size
- Paradise fish120L min · same group, comparable tank size
- Pearl Gourami100L min · same group, similar adult size
- Chocolate gourami80L min · same fish family
- Croaking gourami80L min · same fish family
- Dwarf Gourami60L min · same fish family
- Honey Gourami40L min · same fish family
- Sparkling Gourami40L min · same fish family
- Agassiz’s dwarf cichlidalso 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
- Cockatoo / crested Apistogrammaalso intermediate semi-aggressive, similar tank size
No reverse lookups listed yet.
Plan grid
Key limits are above. Here: pH band, swim level, bioload, and activity.
Swim zones
Care snapshot
Quick compare before you buy. Not a score of how “good” the fish is.
- Beginner ease32
- Peacefulness8
- Community fit0
- Small-tank fit97
- Hardiness54
- Energy54
Numbers are deterministic planning indices from Fishori fields — not a scientific score of your individual fish.
Example setups
Starting points only. Run the pair checker for every fish you add.
Avoid “one of everything” baskets — Opaline gourami belongs in a plan built around territory, line-of-sight breaks, and matched water chemistry.
Compatibility
Tank mates for Opaline gourami
Usually safer (engine GOOD): Swordtail. Conditional (CAUTION — read the pair page before buying): Betta, Boesemani Rainbowfish, Congo Tetra, Corydoras Catfish, Dwarf Gourami. Avoid (RISKY): Chili Rasbora, Ember Tetra. Every name links to a live pair check — the lists are a shortlist, not a stocking plan.
Usually safer
Open a pair page with this fish as the starting point.
Needs planning
Read the blocking rule on each pair page before experimenting.
Usually avoid
Do-not-stock combinations on conservative hobby rules.
Compare with
Run a real pair check: Opaline gourami + Swordtail
- Try Swordtail — open the pair check.
Behaviour and temperament
Opaline gouramis are semi-aggressive labyrinth fish that hold mid-to-top territory. They often ignore robust schoolers in a large tank and lean on dwarf gouramis, bettas, and slow long-finned fish. One male per display is the plan that fails least often.
What sets them off
- Small groups or boredom
- Long-finned or slow tank mates
- Bare tanks without structure
Fin nipping: Will nip long fins or slow fish when the school is too small, bored, or kept in a short tank.
Predation: May eat tank mates small enough to fit the adult mouth — plan adult sizes, not shop sizes.
Territory: Holds a patch (cave, corner, or surface). Break sight lines so neighbours can pass.
Planted tanks: good — easy plant ideas
In the glass: typical and warning signs
- A male holds mid-to-top water and flares at rivals and reflections.
- Resting under floating plants between feeds is normal ownership, not illness.
- Clamped fins under harsh surface current mean turn the filter down first.
- A subordinate male that never feeds is losing a fight, not catching a mystery disease.
- Two males in sight of each other will often fight to injury.
- Nipping on dwarf gouramis or bettas is expected when the surface is shared.
- Remove the losing male the same day fins tear or appetite collapses.
- Rehome the opaline if the tank cannot give ~150L-class room and a calm surface.
Fish behaviour can vary between individuals and tank setups. Always observe new fish closely after introduction.
Water, food, and grouping
Hardness
medium
Diet
omnivore
Opaline gouramis take flake and pellets at the surface and midwater, then ignore food that sinks past them too fast. Offer a quality omnivore staple plus frozen foods a few times a week, and keep portions the fish can finish without fouling the film. They compete poorly with frantic surface feeders, so feed where the gourami actually holds station.
Shrimp & snails
Not shrimp-safe — adults, fry, or both get eaten.
Opaline gourami is fine singly or as a researched pair — check behaviour before doubling up.
- Hold 22 to 28 °C steadily on a real thermometer, not the dial on the heater.
- Aim for pH 6 to 8 and a hardness you can re-test in two weeks. A one-time strip in the shop car park is not a water test.
- Footprint: short wide tanks and tall narrow tanks fish differently for the same volume. Match the tank shape to the swim pattern, not just the litre count.
- Tank volume meets or exceeds 150L published minimum for adults.
- 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.
- No tank mates small enough to fit the adult mouth gap for this species.
Explore and stocking hubs
Tank-mates hub, matching guides, category peers, and litre stocking lists around this species’ minimum tank.
Plan with tools
Check mates as pairs first, then add this fish in the tank builder for the full stocking.
Filtration & heating
A 150L minimum tank needs a filter rated for at least 600L/hr turnover and a heater to hold 22–28°C reliably.
Plant suggestions
Opaline gourami does well in planted tanks. Plants compatible with 22–28°C and pH 6–8:
Research: partially verified · Confidence: high · 3 linked source(s). We do not invent citations.
How Fishori evaluates compatibility (same logic as pair and tank tools).
- Seriously Fish. Trichopodus trichopterus
Primary: aquarium size, water chemistry, behaviour, and compatibility (URL verified in upgrade script; recheck if site content changes).
- FishBase. Trichopodus trichopterus
Secondary: taxonomy, distribution, and maximum length in nature; cross-check with aquarium import lines and measured tank parameters.
- Wikipedia. Trichopodus trichopterus
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.
Common questions about Opaline gourami
- How big do Opaline gourami get?
- Opaline gourami adults reach about 15 cm. Shop fish look smaller; stock for the adult length.
- What size tank does Opaline gourami need?
- 150L is the planning floor for adult swimming space and bioload. A 183L+ tank is the more comfortable long-term footprint. Length and depth matter as much as raw litres for active or territorial fish.
- Are Opaline gourami aggressive?
- Opaline gouramis are semi-aggressive labyrinth fish that hold mid-to-top territory. They often ignore robust schoolers in a large tank and lean on dwarf gouramis, bettas, and slow long-finned fish. One male per display is the plan that fails least often.
- What is the most common mistake with Opaline gourami?
- Housing two male opaline gouramis in one tank because the colour looked good in the shop is how keepers invent a permanently beaten fish. Males fight until one stops eating. Keep a single male as the centrepiece, or give a true pair and a large planted footprint with broken sight lines — not a second male “for company.”
- What fish can live with Opaline gourami?
- The Opaline gourami profile lists Swordtail among its safer pairings (engine-checked GOOD). Betta, Boesemani Rainbowfish, Congo Tetra, Corydoras Catfish are conditional (CAUTION): workable only with the specific conditions on each pair page. Avoid Chili Rasbora, Ember Tetra (RISKY). Run the pair checker for your exact water and tank size before stocking.