Home / Fishes / Carp, barbs, minnows, loaches / Cyprinidae / Red-tailed black shark
No federal permit to keepRed-tailed black shark
Epalzeorhynchos bicolor
Fishes › Carp, barbs, minnows, loaches (Cypriniformes) › Cyprinidae (Carps and barbs)
The red-tailed black shark (Epalzeorhynchos bicolor; syn. Labeo bicolor), also known as the redtail shark, red tailed shark, and redtail sharkminnow, is a species of tropical freshwater fish in the carp family, Cyprinidae.
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: 72–79°F (range recorded for this species).
- pH: 6.5–7.5.
- Hardness: 0–15 dGH.
- Layout: Lives on or near the bottom: floor space and hiding places matter more than height.
- Diet: Eats a varied diet: mix quality prepared foods with frozen and live foods. FishBase classes it as a omnivore.
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: a fairly wide range, from slightly acidic to slightly alkaline, 68–79 °F, pH 6–8, 2–15 dGH.
- Behaviour: temperament territorial; kept alone; not a community fish.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Provided sufficient cover is available this species is relatively unfussy in terms of décor, and should not harm softer-leaved plants.”
- Diet: “Primarily an aufwuchs grazer feeding on algae, small crustaceans, insect larvae, etc., and for it to develop its best colours and condition it should be offered regular meals of small live and frozen foods such as chironomid larvae (bloodworm), Daphnia and…”
- Tankmates: “Though normally sold as such this species is largely unsuitable for the general community aquarium.”
- Breeding: “As far as we know it has not been bred in private aquaria.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Carps and barbs
Applies to most species in this group. Habitat: The listed barbs and freshwater sharks occupy Asian streams, rivers and floodplain waters, with bala sharks also using natural lakes. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- Tiger barbs need a base at least 80 × 30 cm (about 31 × 12 inches), with vegetation and driftwood cover.
- Adult bala shark groups need a base at least 240 × 60 cm (about 96 × 24 inches), ample open swimming space and a heavy, tight lid.
- Red-tailed black sharks need a base at least 120 × 45 cm (about 48 × 18 inches), with rocky refuges.
- Use efficient filtration, water movement and high oxygenation for riverine bala and red-tailed sharks.
Climate & lighting
| Water | 68–78.8°F |
Diet
- Quality flakes or granules containing plant material.
- Live or frozen Daphnia, Artemia and bloodworms.
- For larger bala sharks: chopped earthworms, prawns or mussels.
- For bala sharks: shelled peas, blanched courgette or spinach.
Social life
- Keep tiger barbs in at least 8–10 and bala sharks in at least five. Avoid timid or long-finned companions for tiger barbs. Red-tailed black sharks become territorial toward similar-looking fishes.
Health watch
- Ammonia toxicity.
- Nutritional deficiencies.
Understanding the animal
About this animal
About this animal
It is named after its shark-like appearance and movement, as well as its distinctive red tail.
Quoted from the Wikipedia article “Red-tailed black shark” (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. Stays near the bottom. Inhabits mainstream rivers and floodplains. |
| Water it lives in | Freshwater, 72–79 °F (22–26 °C), pH 6.5–7.5, hardness 15 dH. |
| Climate | Tropical climate. |
What this means for care
- Keep water within its wild range, 72–79 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 97°F (up to 99°F in the hottest sampled areas) |
| Cool-season lows | about 66°F (down to 58°F in the coldest sampled areas) |
| Average temperature | 78–83°F across sampled records |
| Relative humidity | 70–71% on average (driest month about 63%) |
| Rainfall | about 1095 mm a year, with strong wet and dry seasons |
Measured at 7 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 red-tailed black shark (Epalzeorhynchos bicolor; syn. Labeo bicolor), also known as the redtail shark, red tailed shark, and redtail sharkminnow, is a species of tropical freshwater fish in the carp family, Cyprinidae. It is named after its shark-like appearance and movement, as well as its distinctive red tail. It is known locally as the ornated fish Despite its common name, it is more closely related to carp. — 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 |
| Wild diet | Red-tailed black sharks are omnivorous scavengers who are rarely picky eaters. In the wild they eat insects, small crustaceans, worms, detritus, and plant matter. They will also eat algae off rocks, plants, and décor similar to many popular sucker fish in aquariums. — Wikipedia (community-edited) |
| Behavior | Red-tailed black sharks are fast active swimmers that patrol the bottom of the water column. Their movement is reminiscent of sharks as they glide through the water with an oscillatory style of movement. They are known to be good jumpers and can jump out of most aquariums without a lid. — Wikipedia (community-edited) |
| Appearance and size | Red-tailed black sharks grow to be 6 inches (16 cm), but some specimens have reached 7–8 inches (18–20 cm). They have a black elongated body shape that is moderately compressed, and with the snout overhanging the mouth. As juveniles they are all thin and streamlined. — Wikipedia (community-edited) |
| Biology | Inhabits mainstream rivers and floodplains. Omnivorous, feeding on plant matter and small benthic animal. Tens of thousands of specimens are exported annually from Thailand for the ornamental trade, all now captive bred. — FishBase |
| Conservation | Currently the Red Tailed Black Shark is listed as Critically Endangered on the IUCN Red List. The reason as to why the wild population has declined is not well known. Intense overharvesting by the aquarium trade has historically been blamed for being responsible for the species' decline. — Wikipedia (community-edited) |
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 total length. Fish in home aquariums often stay smaller than wild records.
Water temperature
Range the species tolerates in nature; aim for the middle.
Water hardness
Minimum tank footprint
Seriously Fish recommends a tank base of at least 47 × 18 in (about 64 US gallons).
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 — Puntigrus tetrazona Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Seriously Fish — Balantiocheilos melanopterus Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Seriously Fish — Epalzeorhynchos bicolor Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Merck Veterinary Manual — Disorders and Diseases of 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.
- 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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