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No federal permit to keepThree-lined rasbora
Rasbora trilineata
Fishes › Carp, barbs, minnows, loaches (Cypriniformes) › Danionidae (Danios and rasboras)
Rasbora trilineata is a species of ray-finned fish in the genus Rasbora.
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 5.1 in / 13 cm).
- Water: Freshwater.
- Temperature: 73–77°F (range recorded for this species).
- pH: 6–8.
- Hardness: 5–12 dGH.
- Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
- Diet: FishBase classes it as a carnivore.
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 × 18 in (roughly 64 US gallons); space needed is rated “large tank”.
- Water: 72–77 °F, 2–12 dGH.
- Behaviour: temperament peaceful; a shoaling fish best kept in a group of six or more.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Choice of decor is not as critical as water quality and the amount of open swimming-space provided.”
- Diet: “According to stomach analyses of wild specimens this species feeds mainly on invertebrates both aquatic and terrestrial, particularly insects.”
- Tankmates: “This species is very peaceful indeed making it an ideal resident of the larger, well-furnished community tank.”
- Breeding: “This is one of the easier members of the genus to breed and like most cyprinids is an egg-scattering, continuous spawner that exhibits no parental care.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
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.
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.
Climate & lighting
| Water | 64.4–77°F |
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.
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.
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.
Understanding the animal
About this animal
About this animal
Common names include scissortail rasbora and three-lined rasbora. It comes from Southeast Asia.
Quoted from the Wikipedia article “Rasbora trilineata” (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 lives | Lives in freshwater, in rivers and streams, lakes. Uses both the bottom and open water. Found in lakes, swamps, slow flowing areas of rivers, usually in open areas. |
| Water it lives in | Freshwater, 73–77 °F (23–25 °C), pH 6–8, hardness 5–12 dH. |
| Climate | Tropical climate. |
| Behavior to plan for | Breeding: brood hiders. |
What this means for care
- Keep water within its wild range, 73–77 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 91°F (up to 96°F in the hottest sampled areas) |
| Cool-season lows | about 70°F (down to 62°F in the coldest sampled areas) |
| Average temperature | 79–81°F across sampled records |
| Relative humidity | 73–81% on average (driest month about 72%) |
| Rainfall | about 2314 mm a year |
Measured at 87 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.
| Overview | Rasbora trilineata is a species of ray-finned fish in the genus Rasbora. Common names include scissortail rasbora and three-lined rasbora. It comes from Southeast Asia. Its length is up to 15 cm (6"). — Wikipedia (community-edited) |
| Where it lives | Home 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 |
| Reproduction | Provisionally considered a brood hider. In captivity, this species spawns only in darkened aquaria and deposits adhesive eggs under an object on the bottom. — FishBase |
| Biology | Found in lakes, swamps, slow flowing areas of rivers, usually in open areas (, 57235 ). Seems to prefer habitats in forest. A common resident of surface waters in streams, canals, ditches and occasionally of reservoirs in lowland areas. — 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.
Maximum recorded lifespan
Longest recorded lifespan reported by each database; typical lifespans are usually shorter.
Adult length
Maximum recorded length. Measured as total length. Fish in home aquariums often stay smaller than wild records.
Water temperature
Range the species tolerates in nature; aim for the middle.
pH
Minimum tank footprint
Seriously Fish recommends a tank base of at least 47 × 18 in (about 64 US gallons).
Veterinary & husbandry research
Veterinary & husbandry research
- Complete mitochondrial genome of Rasbora trilineata (Cypriniformes, Cyprinidae) Ho CW et al., Mitochondrial DNA. Part A, DNA mapping, sequencing, and analysis 2016
- Breeding and Ontogeny of the Aquarium-Traded Scissortail Rasbora (Rasbora trilineata) Kasamawut K et al., Animals: an open access journal from MDPI 2025
Peer-reviewed papers that mention this species alongside captivity, zoos, veterinary care or aquaculture. Some cover several species or mention it only in passing, so check the abstract. 170
Sources for this sheet
- 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.
- 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.
- Seriously Fish: Zebra danio (Danio / Brachydanio rerio) Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Seriously Fish: Trigonostigma heteromorpha Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Seriously Fish: Devario aequipinnatus Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Seriously Fish: Danio / Celestichthys margaritatus Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.
- PubMed (U.S. National Library of Medicine) Peer-reviewed researchIndex of peer-reviewed veterinary, zoo and husbandry research.
- 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.
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