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Lambchop rasbora

Trigonostigma espei

Fishes › Carp, barbs, minnows, loaches (Cypriniformes) › Danionidae (Danios and rasboras)

The espei rasbora, or lambchop rasbora (Trigonostigma espei) is a species of ray-finned fish in the genus Trigonostigma.

Aquarium hobby
Experience: Easy
Lambchop rasbora
Photo: AverageWalrus, CC BY-SA 4.0, via Wikimedia Commons
FamilyDanios and rasboras
Adult lengthup to 1.2 in
WaterFreshwater
HabitatLives in freshwater

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 1.0 in / 2.5 cm).
  • Water: Freshwater.
  • Temperature: 73–82°F (range recorded for this species).
  • pH: 6–6.5.
  • Hardness: 0–12 dGH.
  • 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 24 × 12 in (roughly 14 US gallons); space needed is rated “modest tank”.
  • Water: a fairly wide range, from slightly acidic to slightly alkaline, 73–82 °F, pH 5.5–7.5, 1–10 dGH.
  • Behaviour: temperament peaceful; a shoaling fish best kept in a group of six or more; suited to a community tank.
  • Difficulty: Easy (Seriously Fish rating).

Short excerpts from the species profile:

  • Setup: “Choice of decor is not especially critical although it tends to show better colouration when maintained in a well-furnished set-up with a dark substrate, and it's a relatively popular choice for carefully-aquascaped arrangements.”
  • Diet: “Probably a micropredator feeding on small insects, worms, crustaceans, and other zooplankton in nature.”
  • Tankmates: “This species is very peaceful indeed making it an ideal resident of the well-maintained community tank.”
  • Breeding: “This species exhibits no parental care although it does utilise a different spawning method to most small cyprinids as the eggs are attached to the underside of broad plant leaves or other objects rather than scattered randomly.”

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

Group care guide

Danios and rasboras

Applies to most species in this group. Habitat: These Asian fishes occupy habitats ranging from zebra-danio pools and rice paddies to shaded harlequin streams, rocky Devario streams and planted galaxy-rasbora wetlands. [fg159-zebra, fg159-harlequin, fg159-giant, fg159-galaxy]. Individual species can differ, so compare with the species numbers above and the linked sources.

Level 2 reflects common aquarium species. Water range is ONLY for zebra danios; harlequins use 69.8–82.4°F, galaxy rasboras 68–78.8°F and D. aequipinnatus 60.8–78.8°F. [fg159-zebra, fg159-harlequin, fg159-galaxy, fg159-giant] Avoid routine tannin-rich wood/leaf additions for galaxy rasboras. [fg159-galaxy] Giant danios are often misidentified as D. aequipinnatus. [fg159-giant] Obtain separate profiles for the listed Rasbora and T. espei before using these examples as a stocking prescription.

Housing & setup

  • Use at least 90 × 30 cm (36 × 12 in) for zebra danios.
  • Harlequins require at least 60 × 30 cm (24 × 12 in), shaded planted cover and subdued light.
  • Devario aequipinnatus needs at least 120 × 45 cm (48 × 18 in), oxygenated water, moderate flow and a tight lid.
  • Galaxy rasboras need dense planting and broken sight lines in at least 45 × 30 cm (18 × 12 in), with gentle sponge filtration.
  • Match chemistry: harlequins pH 5.0–7.5, 1–12 dGH; galaxy rasboras pH 6.5–7.5, 5–15 dGH.

Sources 877878879880

Climate & lighting

Water64.4–77°F

Sources 877878879880

Diet

  • Quality flakes or granules sized to the fish.
  • Live or frozen Daphnia and Artemia.
  • Bloodworms for zebra danios, harlequins and Devario.
  • Small sinking foods for galaxy rasboras, which rarely feed at the surface.

Sources 877878879880

Social life

  • Keep zebra danios and harlequins in groups of at least 8–10. Galaxy males spar: dense cover and larger groups distribute aggression. Active Devario can overwhelm timid feeders.

Sources 877878879880

Health watch

  • Pseudoloma microsporidiosis in zebra danios.
  • Pleistophora infection and columnaris can produce similar white lesions in zebra danios.
  • Nipped fins among rival galaxy males.

Sources 877878879880

Understanding the animal

About this animal

About this animal

It is named after the dark band that appears like a lamb chop along its body. The species is predominantly found in Thailand and Cambodia, with a population additionally known to occur on the island of Phú Quốc in Vietnam.

Quoted from the Wikipedia article “Trigonostigma espei” (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, in rivers and streams, lakes, mangroves. Uses both the bottom and open water. Occurs in ponds, pools, marshes and swamps with heavy growth of submerged aquatic plants.
Water it lives inFreshwater, 73–82 °F (23–28 °C), pH 6–6.5, hardness 12 dH.
ClimateTropical climate.
Behavior to plan forBreeding: open water/substratum egg scatterers.

What this means for care

  • Keep water within its wild range, 73–82 °F.
  1. FishBase species summary: Trigonostigma espei
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 espei rasbora, or lambchop rasbora (Trigonostigma espei) is a species of ray-finned fish in the genus Trigonostigma. It is named after the dark band that appears like a lamb chop along its body. The species is predominantly found in Thailand and Cambodia, with a population additionally known to occur on the island of Phú Quốc in Vietnam. — 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
ReproductionSpawning occurs in shallow water of 15-20cm of depth. — FishBase
BiologyOccurs in ponds, pools, marshes and swamps with heavy growth of submerged aquatic plants. — 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 sources1.1in
FishBase 1641
Seriously Fish species profiles 1671.2

Maximum recorded length. Measured as standard length (snout to the base of the tail, not counting the tail fin). Fish in home aquariums often stay smaller than wild records.

Water temperature

Average of sources73–82°F
FishBase 16473–82
Seriously Fish species profiles 16773–82

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

pH

Average of sources5.8–7
FishBase 1646–6.5
Seriously Fish species profiles 1675.5–7.5

Water hardness

Reported1–10dGH
Seriously Fish species profiles 1671–10

Minimum tank footprint

Reported24in
Seriously Fish species profiles 16724

Seriously Fish recommends a tank base of at least 24 × 12 in (about 14 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. Seriously Fish: Zebra danio (Danio / Brachydanio rerio) Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
  4. Seriously Fish: Trigonostigma heteromorpha Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
  5. Seriously Fish: Devario aequipinnatus Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
  6. Seriously Fish: Danio / Celestichthys margaritatus Experienced keeper or breederAdded 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.
  8. iNaturalist (captive observations) Community referenceCommunity observation platform run by the California Academy of Sciences and National Geographic; observations marked captive show animals living in homes, zoos and aquariums.