Identity and search names
- Common name
- Lambchop rasbora
- Scientific name
- Trigonostigma espei
- Other names
- Espei rasbora, False harlequin rasbora, Rasbora espei
- Category
- Freshwater fish
- Group
- Rasboras, danios and minnows
- Origin
- Mekong-region lowland waters of Thailand and Cambodia, with records in nearby Southeast Asian drainages
- Review outcome
- PASSED
Environment and housing
- Environment
- Freshwater
- Care level
- Beginner to intermediate
- Adult size
- Usually about 2.5–3 cm standard length and 3–3.5 cm total length
- Expected lifespan
- About 4–7 years
- Minimum housing
- At least 60 L with a 60 cm or longer swimming length for a proper school
- Temperature
- 23–28 °C
- pH
- 5.0–7.5
- Hardness or minerals
- Very soft to moderately hard
- Salinity
- Freshwater
- Lighting
- Subdued to moderate with floating shade and planted margins
- Social structure
- Keep at least 10–12; larger schools show better colour, coordination and confidence
- Placement or swimming zone
- Middle and upper water
- Temperament
- Very peaceful and strongly schooling
- Compatibility
- Use tiny peaceful fish and invertebrates too large to swallow; avoid large predators and aggressive nano fish
- Habitat structure
- Mature planted aquarium with dark substrate, wood or leaf litter, shaded margins and open mid-water
Feeding and nutrition
- Diet
- Minute insects, crustaceans and fine quality prepared foods
- Feeding frequency
- Feed small varied portions once or twice daily and ensure food size suits the small mouth
Breeding and reproduction
- Breeding or reproduction
- A pair turns beneath broad leaves and attaches small numbers of adhesive eggs to the underside. Adults provide no care and may eat eggs or fry
- Parental care
- No parental care
System demands
- Filtration
- Use mature biological filtration sized for the full adult group and feeding load, with intake protection where juveniles, long fins or small fish are present. Provide steady turnover without preventing normal swimming or resting.
- Aeration
- Maintain strong surface gas exchange and stable dissolved oxygen. Increase aeration during warm weather, medication, transport recovery, breeding crowding or any ammonia or nitrite event.
- Maintenance
- Test ammonia, nitrite and nitrate, remove waste from feeding and shelter zones, and perform regular temperature- and chemistry-matched water changes before nitrate or dissolved organics accumulate.
Detailed husbandry
- Identity scope
- This profile applies to Trigonostigma espei. It is separate from T. heteromorpha and T. hengeli; the narrow lambchop-shaped flank mark and verified supply identity matter when building a consistent school.
- Adult size and space
- Usually about 2.5–3 cm standard length and 3–3.5 cm total length. At least 60 L with a 60 cm or longer swimming length for a proper school. Plan around adult dimensions, activity, social structure, aggression and waste production rather than sale size.
- Social structure
- Keep at least 10–12; larger schools show better colour, coordination and confidence
- Placement or swimming zone
- Primary zone: Middle and upper water. Keep that zone usable for movement, feeding and refuge.
- Feeding ecology
- Minute insects, crustaceans and fine quality prepared foods
- Feeding plan
- Feed small varied portions once or twice daily and ensure food size suits the small mouth
- Water stability
- Maintain 23–28 °C; pH 5.0–7.5; hardness/minerals: Very soft to moderately hard. Stable oxygenation and nitrogen-cycle control matter more than chasing one exact number.
- Adult projected load
- Plan capacity for Keep at least 10–12; larger schools show better colour, coordination and confidence at the documented adult size (Usually about 2.5–3 cm standard length and 3–3.5 cm total length) in At least 60 L with a 60 cm or longer swimming length for a proper school. Include feeding intensity, territorial behaviour and breeding growth rather than counting sale-size juveniles.
- Filtration
- Use mature biological filtration sized for the full adult group and feeding load, with intake protection where juveniles, long fins or small fish are present. Provide steady turnover without preventing normal swimming or resting.
- Aeration
- Maintain strong surface gas exchange and stable dissolved oxygen. Increase aeration during warm weather, medication, transport recovery, breeding crowding or any ammonia or nitrite event.
- Maintenance
- Test ammonia, nitrite and nitrate, remove waste from feeding and shelter zones, and perform regular temperature- and chemistry-matched water changes before nitrate or dissolved organics accumulate.
- Habitat structure
- Mature planted aquarium with dark substrate, wood or leaf litter, shaded margins and open mid-water
- Compatibility plan
- Use tiny peaceful fish and invertebrates too large to swallow; avoid large predators and aggressive nano fish
- Breeding plan
- A pair turns beneath broad leaves and attaches small numbers of adhesive eggs to the underside. Adults provide no care and may eat eggs or fry Parental care: No parental care.
- Quarantine
- Quarantine new fish in a separate cycled aquarium with dedicated equipment. Match temperature and mineral chemistry gradually, confirm feeding and normal respiration, and never add transport water to the established aquarium.
- Welfare checks
- Maintain the stated adult space and social structure, verify feeding and intervene early when injury, exclusion, weight loss, abnormal respiration or altered behaviour appears. Small groups are not enough. This species is also routinely mixed with harlequin and glowlight rasboras under loose trade names.
- Biosecurity and release
- Never release fish, fry, eggs, aquarium water, sediment, plants or live foods into drains, dams or natural waterways. Confirm current Australian import conditions and South Australian possession, trade and movement rules before acquisition or transfer.
- Main risk
- Small groups are not enough. This species is also routinely mixed with harlequin and glowlight rasboras under loose trade names.
- Overridable warnings
- Small groups are not enough. This species is also routinely mixed with harlequin and glowlight rasboras under loose trade names. Any override must still preserve adult space, social welfare, stable chemistry, oxygen and filter capacity.
Welfare and risk
- Welfare checks
- Maintain the stated adult space and social structure, verify feeding and intervene early when injury, exclusion, weight loss, abnormal respiration or altered behaviour appears. Small groups are not enough. This species is also routinely mixed with harlequin and glowlight rasboras under loose trade names.
- Main warning
- Small groups are not enough. This species is also routinely mixed with harlequin and glowlight rasboras under loose trade names.
- Biosecurity
- Never release fish, fry, eggs, aquarium water, sediment, plants or live foods into drains, dams or natural waterways. Confirm current Australian import conditions and South Australian possession, trade and movement rules before acquisition or transfer.
Sources
Source note
Current identity or scope, husbandry, system-demand, welfare and Australian biosecurity evidence checked; active retired-source links removed; all AquaNexus wording is original.
- Eschmeyer’s Catalog of Fishes — Trigonostigma espei — Current accepted-name, synonym, family and habitat check
- Eschmeyer’s Catalog of Fishes — Trigonostigma espei — Accepted-name, synonym and taxonomic-placement cross-check
- Seriously Fish — Trigonostigma espei — Adult size, natural habitat, water range and underside-leaf spawning cross-check
- IUCN Red List search — Trigonostigma espei — Conservation-status and wild-provenance cross-check
- PIRSA — South Australian noxious fish list — Current South Australian possession and trade restriction cross-check
- DAFF — importing live ornamental fish to Australia — Current Australian live-fish import pathway and permitted-species warning