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Frail gourami

Ctenops nobilis

Fishes › Gouramis, bettas, snakeheads (Anabantiformes) › Osphronemidae (Gouramis and bettas)

The frail gourami (Ctenops nobilis) or noble gourami is a mouth brooding species of gourami native to northeastern India and Bangladesh.

Aquarium hobby
Experience: Beginner
FamilyGouramis and bettas
Adult lengthup to 3.9 in
WaterFreshwater, brackish

Care at a glance

Species-specific aquarium care

  • Tank: At least 24 in long and 12 in front to back for one adult (adults commonly reach about 3.9 in / 10 cm).
  • Water: Freshwater (tolerates brackish).
  • Temperature: 68–75°F (range recorded for this species).
  • Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.

Calculated from this species' own FishBase record: tank size from its typical adult length and swimming zone, water values from its recorded ranges. The group guide below fills in general care.

Care guide

Species care notes

  • Tank: a base of at least 47 × 12 in (roughly 29 US gallons); space needed is rated “large tank”.
  • Water: a fairly wide range, from slightly acidic to slightly alkaline, 59–77 °F, pH 5–7.5, 2–12 dGH.
  • Behaviour: a shoaling fish best kept in a group of six or more; not a community fish.
  • Difficulty: Moderate (Seriously Fish rating).

Short excerpts from the species profile:

  • Setup: “Provided adequate cover and structure is available this species is unfussy with regards to décor with ceramic flowerpots, lengths of plastic piping and other artificial materials all useful additions.”
  • Diet: “Chiefly a micropredator feeding on small aquatic crustaceans, worms, insect larvae and other zooplankton.”
  • Tankmates: “Not recommended for the average community aquarium but can be maintained alongside other non- piscivorous anabantoids in larger set-ups.”

From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167

Group care guide

Gouramis and labyrinth fish

Applies to most species in this group. Habitat: Warm, still, vegetated waters. Individual species can differ, so compare with the species numbers above and the linked sources.

Housing & setup

  • Planted, calm tanks with floating plants; they breathe air at the surface, so leave a gap under the lid.

Sources 117119164118280

Diet

  • Food acceptance is species-specific. Parosphromenus deissneri needs tiny live invertebrate foods and commonly refuses dried foods; a pellet/flake staple cannot cover every labyrinth fish.

Sources 117119164118280

Health watch

  • Males are territorial; dwarf gourami iridovirus.

Sources 117119164118280

Understanding the animal

No real photograph of this species is freely available yet. The only images we found were scientific illustrations or maps, so none is shown. It stays on the site because there is evidence it is kept (see “Kept in captivity?”), but it is rarely kept or rarely photographed. If you keep one and can share a photo, we would love to add it.
About this animal

About this animal

It grows to a length of 10 cm (3.9 in). It is only seldom found in the aquarium trade, due to its extreme sensitivity to shipping stress and high levels of aggression.

Quoted from the Wikipedia article “Frail gourami” (CC BY-SA 4.0) 174

In the wild

In the wild

From this species’ own FishBase record (habitat, bottom type, water and breeding data), not its family. Good care copies these conditions.1

Where it livesLives in freshwater and brackish water. Uses both the bottom and open water. Found in rivers and lakes with overgrown vegetation.
Water it lives inFreshwater / brackish water, 68–75 °F (20–24 °C).
ClimateTropical climate.

What this means for care

  • Keep water within its wild range, 68–75 °F.
  • It tolerates or needs brackish water; check salinity needs before setup.
  1. FishBase species summary: Ctenops nobilis
Native climate (measured)

Native climate (measured)

Warm-season highsabout 90°F (up to 96°F in the hottest sampled areas)
Cool-season lowsabout 52°F (down to 50°F in the coldest sampled areas)
Average temperature76–78°F across sampled records
Relative humidity74–77% on average (driest month about 62%)
Rainfallabout 2476 mm a year, with strong wet and dry seasons

Measured at 6 wild occurrence records sampled against WorldClim 2.1 climate data (1970–2000 averages). Air conditions in the range are ecological context, not enclosure settings: microhabitats such as burrows, leaf litter or basking rocks can be cooler, warmer or more humid.

From the sources

From the sources

Quoted from the matching sections of reputable sources for this exact species. Specialist databases are used first; Wikipedia (community-edited, CC BY-SA 4.0) only fills gaps. Other sources are short credited quotes.

OverviewThe frail gourami (Ctenops nobilis) or noble gourami is a mouth brooding species of gourami native to northeastern India and Bangladesh. It grows to a length of 10 cm. It is only seldom found in the aquarium trade, due to its extreme sensitivity to shipping stress and high levels of aggression. The frail gourami is the only known member of its genus. — Wikipedia (community-edited)
Where it livesHome ranges Population dynamics Growth parameters Max. ages / sizes Length-weight rel. Length-frequencies Mass conversion Recruitment Abundance Life cycle Reproduction Maturity Maturity/Gills rel. — FishBase
BiologyFacultative air-breathing; Found in rivers and lakes with overgrown vegetation, streams, ponds and beels. — FishBase

Data and studies

The numbers

The numbers

Each bar is what one source reports. Where several sources weigh in, the dashed gold band marks their average.

Adult length

Average of sources3.9in
FishBase 1643.9
Seriously Fish species profiles 1673.9

Maximum recorded length. Measured as total length. Fish in home aquariums often stay smaller than wild records.

Water temperature

Average of sources63.5–76°F
FishBase 16468–75
Seriously Fish species profiles 16759–77

Range the species tolerates in nature; aim for the middle.

pH

Reported5–7.5
Seriously Fish species profiles 1675–7.5

Water hardness

Reported2–12dGH
Seriously Fish species profiles 1672–12

Minimum tank footprint

Reported47in
Seriously Fish species profiles 16747

Seriously Fish recommends a tank base of at least 47 × 12 in (about 29 US gallons).

Sources for this sheet

  1. FishBase (Froese & Pauly, eds.), version 24.07 Peer-reviewed researchThe global scientific database on fishes, maintained by a consortium of research institutions; every value is referenced.
  2. Seriously Fish species profiles Experienced keeper or breederLong-running aquarium reference written and peer-checked by experienced fishkeepers and ichthyologists; each profile covers habitat, tank size, water, diet, behaviour and breeding.
  3. Merck Veterinary Manual: Management of aquarium fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
  4. Merck Veterinary Manual: Types and features of aquatic systems Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
  5. Merck Veterinary Manual: Nutritional diseases of fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
  6. Seriously Fish — Parosphromenus deissneri Zoo, university or veterinaryAdded in the 2026 source-checked care-guide review.
  7. Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.