Home / Fishes / Carp, barbs, minnows, loaches / Cyprinidae / Harlequin sharkminnow
No federal permit to keepHarlequin sharkminnow
Labeo cyclorhynchus
Fishes › Carp, barbs, minnows, loaches (Cypriniformes) › Cyprinidae (Carps and barbs)
The harlequin sharkminnow (Labeo cyclorhynchus) is a freshwater cyprinid fish from central Africa.
Care at a glance
Species-specific aquarium care
- Tank: At least 30 in long and 12 in front to back for one adult (adults commonly reach about 6.3 in / 16 cm).
- Water: Freshwater.
- Temperature: 70–81°F (range recorded for this species).
- 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
- Water: a fairly wide range, from slightly acidic to slightly alkaline, 70–81 °F, pH 6–7.5, 3–15 dGH.
- Behaviour: temperament territorial.
- Difficulty: Easy (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “This species will do well in most larger, well-maintained tanks if plenty of hiding places are provided although it might harm softer-leaved plants.”
- Diet: “Labeo species are primarily aufwuchs feeders grazing submerged surfaces for algae, microscopic animals and other detritus.”
- Tankmates: “This species is largely unsuitable for the general community aquarium though this does not mean to say it must be kept alone, rather that tankmates must be chosen with care.”
- Breeding: “As far as we know it has not been bred in 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 also known as the harlequin shark and variegated shark, especially in the aquarium hobby.
Quoted from the Wikipedia article “Harlequin sharkminnow” (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. Uses both the bottom and open water. |
| Water it lives in | Freshwater, 70–81 °F (21–27 °C). |
| Climate | Tropical climate. |
What this means for care
- Keep water within its wild range, 70–81 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 87°F (up to 89°F in the hottest sampled areas) |
| Cool-season lows | about 66°F (down to 62°F in the coldest sampled areas) |
| Average temperature | 76–78°F across sampled records |
| Relative humidity | 78–81% on average (driest month about 75%) |
| Rainfall | about 1682 mm a year |
Measured at 20 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 harlequin sharkminnow (Labeo cyclorhynchus) is a freshwater cyprinid fish from central Africa. It is also known as the harlequin shark and variegated shark, especially in the aquarium hobby. — 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 | The harlequin sharkminnow has a creamy yellow ground colour marked with grey, black mottling with translucent fins which are mottle black. They take their vernacular name from the vague resemblance these and similar freshwater species bear to true sharks, in that they have an elongated body with stiff fins. The colour and markings of the fish are most intense in the juveniles, but the colours fade as the fish mature. — Wikipedia (community-edited) |
| Biology | The harlequin sharkminnow is a benthopelagic species, and they are highly adaptable feeders with an omnivorous diet and their main food source is aufwuchs, including micofauna and algae, which they graze from the bottom. In some areas these fish form an association with groups of common hippopotamus (Hippopotamus amphibius) and the fish browse on the mammals' skin. — 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.
pH
Water hardness
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.
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