Home / Fishes / Carp, barbs, minnows, loaches / Danionidae / Zebra danio
No federal permit to keepZebra danio
Danio rerio
Fishes › Carp, barbs, minnows, loaches (Cypriniformes) › Danionidae (Danios and rasboras)
The zebrafish (Danio rerio) is a species of danionin belonging to the genus Danio in the suborder Cyprinoidei.
Care at a glance
Species-specific values
Values researched for this exact species. Where they differ from the group guide below, follow these. Air, surface and water temperatures are listed separately, and each source is kept as published rather than averaged.
| Water temperature | 64–77 °F (18–25 °C) Maintenance recommendations from this source; do not replace with a multisource average. The source uses the combination Brachydanio rerio; this record retains the input CSV name. | 262 |
| Water pH | 6–8 Maintenance recommendations from this source; do not replace with a multisource average. The source uses the combination Brachydanio rerio; this record retains the input CSV name. | 262 |
| Water general hardness | 5–20 dGH Maintenance recommendations from this source; do not replace with a multisource average. The source uses the combination Brachydanio rerio; this record retains the input CSV name. | 262 |
| Adult standard length | 50 mm Maximum standard length reported by source; excludes caudal fin, not total body length. | 262 |
| Minimum tank base | length: 90 cm; width: 30 cm Minimum aquarium base recommended by this source, not a tank-volume specification. | 262 |
Species-specific aquarium care
- Tank: At least 24 in long and 12 in front to back for one adult (adults commonly reach about 1.5 in / 3.8 cm).
- Water: Freshwater.
- Temperature: 64–75°F (range recorded for this species).
- pH: 6–8.
- Hardness: 5–19 dGH.
- Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
- Diet: A predator: feed meaty foods sized to its mouth (frozen fish, shrimp, worms); it will eat tankmates that fit in its mouth. 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 35 × 12 in (roughly 21 US gallons); space needed is rated “large tank”.
- Water: a fairly wide range, from slightly acidic to slightly alkaline, 64–77 °F, pH 6–8, 5–20 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 décor is not especially critical though it tends to show better colouration in a heavily-planted set-up with a dark substrate.”
- Diet: “Stomach analyses of wild specimens have shown it to be a micropredator, feeding on aquatic crustaceans and other invertebrates such as mosquito larvae.”
- Tankmates: “This species is very peaceful indeed and can be combined with many of the most popular fish in the hobby including other small cyprinids as well as tetras, livebearers, rainbowfishes, anabantoids, catfishes and loaches.”
- Breeding: “An excellent choice for those new to breeding fishes in aquaria.”
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
Native to South Asia, it is a popular, hardy aquarium fish, frequently sold under the trade name zebra danio (thus often mislabeled as a "tropical fish", even though they also inhabit subtropical and temperate waters). The zebrafish is extensively used as a vertebrate model organism in scientific research, particularly developmental biology, but also gene function, oncology, teratology, and drug development, in particular pre-clinical development, due to its scalability from high numbers of offspring and ease of drug delivery through water into the gills.
Quoted from the Wikipedia article “Zebrafish” (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. Adults inhabit streams, canals, ditches, ponds and beels. |
| Water it lives in | Freshwater, 64–75 °F (18–24 °C), pH 6–8, hardness 5–19 dH. |
| Climate | Tropical climate. |
| Wild diet | Hunting macrofauna (predator). |
| Behavior to plan for | Breeding: open water/substratum egg scatterers. |
What this means for care
- Keep water within its wild range, 64–75 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 93°F (up to 104°F in the hottest sampled areas) |
| Cool-season lows | about 52°F (down to 46°F in the coldest sampled areas) |
| Average temperature | 72–80°F across sampled records |
| Relative humidity | 63–77% on average (driest month about 55%) |
| Rainfall | about 1798 mm a year, with strong wet and dry seasons |
Measured at 94 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 | The zebrafish (Danio rerio) is a species of danionin belonging to the genus Danio in the suborder Cyprinoidei. Native to South Asia, it is a popular, hardy aquarium fish, frequently sold under the trade name zebra danio (thus often mislabeled as a "tropical fish", even though they also inhabit subtropical and temperate waters). — 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 |
| Social life and communication | Olfaction, vision, and motion detection via the lateral line system help zebrafish perceive their local environment and evade potential predators. — Animal Diversity Web |
| Wild diet | They get most of their food from the water column, mainly eating zooplankton and aquatic insects. — Animal Diversity Web |
| Reproduction | From Johnson (1932), 'a female never extrudes eggs during active courtship until the genital organ comes in contact with that of the male, whereupon a small stream of eggs is ejected'. Violent dashing and chasing characterise courtship finally culminating in eggs being shed a few at a time, settling freely without adhering to the bottom surface. — FishBase |
| Lifespan | In the wild, most zebrafish live to be one year old. — Animal Diversity Web |
| Appearance and size | Maximum length 3.8 cm sl male/unsexed. — FishBase |
| Biology | Adults inhabit streams, canals, ditches, ponds and beels. They occur in slow-moving to stagnant standing water bodies, particularly rice-fields; and lower reaches of streams. Common in rivulets at foot hills. — FishBase |
| History and naming | The zebrafish is a derived member of the genus Danio, of the family Cyprinidae. It has a sister-group relationship with Danio aesculapii. Zebrafish are also closely related to the genus Devario, as demonstrated by a phylogenetic tree of close species. — Wikipedia (community-edited) |
Data and studies
Researched care notes
Researched care notes
Findings checked against veterinary, zoo, welfare, keeper and peer-reviewed sources. Air, basking-surface and water temperatures are kept separate, and where sources disagree both are shown. “Study” notes report what a paper measured, not a universal rule.
Zebrafish (species-focused enrichment evidence)
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. The AnAge record comes from an animal in human care.
Adult length
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
Range the species tolerates in nature; aim for the middle.
Minimum tank footprint
Seriously Fish recommends a tank base of at least 35 × 12 in (about 21 US gallons).
Veterinary & husbandry research
Veterinary & husbandry research
- Social Preference Tests in Zebrafish: A Systematic Review Ogi A et al., Frontiers in veterinary science 2020
- A zebrafish-centric approach to antiepileptic drug development Baraban SC et al., Disease models & mechanisms 2021
- Streptococcus agalactiae infection in zebrafish larvae Kim BJ et al., Microbial pathogenesis 2015
- Understanding zebrafish aggressive behavior Zabegalov KN et al., Behavioural processes 2019
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. See all 525 on PubMed → 170
Sources for this sheet
- AnAge: The Animal Ageing and Longevity Database (Human Ageing Genomic Resources) Peer-reviewed researchCurated, referenced longevity and life-history records for thousands of species; maximum lifespans are often from zoo animals.
- 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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