Home / Fishes / Gouramis, bettas, snakeheads / Scarlet badis
No federal permit to keepScarlet badis
Dario dario
Fishes › Gouramis, bettas, snakeheads (Anabantiformes) › Badidae (Badis and scarlet badis)
The scarlet badis (Dario dario) is a tropical freshwater fish and one of the smallest known percoid fish species.
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 0.6 in / 1.52 cm).
- Water: Freshwater.
- 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 18 × 12 in (roughly 11 US gallons); space needed is rated “modest tank”.
- Water: a fairly wide range, from slightly acidic to slightly alkaline, 64–79 °F, pH 6.5–8.5, 1–15 dGH.
- Behaviour: temperament fights its own; in a pair; not a community fish.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Best-maintained in a well-structured arrangement with plenty of cover.”
- Diet: “Dario species are micropredators feeding on small aquatic crustaceans, worms, insect larvae and other zooplankton.”
- Tankmates: “Slow-moving with a retiring nature, and easily intimidated or outcompeted for food by larger or more aggressive tankmates.”
- Breeding: “Substrate-spawner forming temporary pair bonds.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Badis and scarlet badis
Applies to most species in this group. Habitat: South Asian freshwater streams and vegetated margins, with Dario dario favoring shallow clear streams and Badis badis commonly inhabiting slower, turbid, plant-bearing water (dario; badis). Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- For D. dario, use at least a 45 × 30 cm (17.7 × 11.8 inch) base for a pair or one male with several females (dario).
- For B. badis, use at least an 80 × 30 cm (31.5 × 11.8 inch) base for a pair or small group (badis).
- Provide sand or fine gravel, dense cover, branches and leaf litter, with moss particularly useful for Dario spawning (dario; badis).
- Supply dispersed caves, such as half-coconut shells or accessible clay pots, for Badis spawning and separate male territories (badis).
- Use subdued lighting and gentle filtration for B. badis (badis).
Climate & lighting
| Water | 64.4–77°F |
Diet
- Live or frozen Artemia; use nauplii for tiny Dario (dario; badis).
- Daphnia (dario; badis).
- Grindal, micro- or banana worms for Dario (dario).
- Glassworm for Badis (badis).
Social life
- Use one male in small tanks; rival males need separate territories in larger setups. These slow feeders are easily outcompeted. Avoid mixing Badis species because of hybridization risk, and expect predation on small ornamental shrimp (dario; badis).
Health watch
- Obesity and increased disease susceptibility associated with bloodworm or Tubifex diets (dario; badis).
- Feeding failure from intimidation or food competition (dario; badis).
- Ammonia/nitrite toxicity (fish_vet).
Understanding the animal
About this animal
About this animal
It is a micropredator, feeding on small aquatic crustaceans, worms, insect larvae and other zooplankton. It is sold under a variety of names (Badis badis bengalensis, B. bengalensis) in the aquarium trade.
Quoted from the Wikipedia article “Scarlet badis” (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. Uses both the bottom and open water. Collected from a stream (in November, dry season) which varied in width between 2-5 m and in depth 30-70 cm; the water is crystal clear and around 26°C; dense vegetation of aquatic plants (e.g. Limnophila, Hygrophila, Vallisneria, Ottelia, and Rotala species); bottom cover was sand and fine gravel. |
| Water it lives in | Freshwater, depth 0–1 m. |
| Climate | Tropical climate. |
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 scarlet badis (Dario dario) is a tropical freshwater fish and one of the smallest known percoid fish species. It is a micropredator, feeding on small aquatic crustaceans, worms, insect larvae and other zooplankton. It is sold under a variety of names (Badis badis bengalensis, B. bengalensis) in the aquarium trade. — 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 |
| Appearance and size | Scarlet badis are among the smallest percoid fish species. Males usually do not exceed 2 cm, with the females being even smaller around 1.3 cm, the maximum length can reach 3.5 cm to 4 cm. Apart from the size difference, the sexes are easy to distinguish by the vibrant colors and prominent fins of the male. — Wikipedia (community-edited) |
| Biology | Collected from a stream (in November, dry season) which varied in width between 2-5 m and in depth 30-70 cm; the water is crystal clear and around 26°C; dense vegetation of aquatic plants (e.g. Limnophila, Hygrophila, Vallisneria, Ottelia, and Rotala species); bottom cover was sand and fine gravel. — 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
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; aim for the middle.
pH
Water hardness
Minimum tank footprint
Seriously Fish recommends a tank base of at least 18 × 12 in (about 11 US gallons).
Veterinary & husbandry research
Veterinary & husbandry research
- Effects of homochromatic lights on the physiological responses and morphochromatic traits of scarlet badis, Dario dario (Hamilton, 1822) Siva N et al., Fish physiology and biochemistry 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 — Dario dario Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Seriously Fish — Badis badis Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Merck Veterinary Manual — Management of Aquarium Fish Zoo, university or veterinaryAdded 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.
