Common name
Red-tail black shark
Scientific name
Epalzeorhynchos bicolor
Category
Freshwater fish
Group
Algae grazers and shark-like cyprinids
Environment
Freshwater
Origin
Chao Phraya basin of Thailand; wild populations are highly threatened and aquarium stock is captive-produced
Care level
Intermediate to advanced
Adult size
Up to about 13 cm total length
Expected lifespan
About 8–12 years
Minimum housing
At least 250 L for one adult, with a long footprint and multiple defended refuges
Temperature
22–27 °C
pH
6.0–8.0
Hardness / minerals
Soft to moderately hard
Salinity
Freshwater
Lighting
Moderate
Placement / swimming zone
Bottom and middle water

Identity and search names

Single-species profile for Epalzeorhynchos bicolor. Labeo bicolor is the original combination; do not confuse it with rainbow shark or similarly named cyprinids. Search names include Red-tail black shark, Red-tailed black shark, Redtail sharkminnow, Epalzeorhynchos bicolor, Epalzeorhynchus bicolor, Labeo bicolor.

Environment and housing

Long mature aquarium with strong filtration, current, oxygenation, caves, wood and broken sightlines across the bottom

Feeding and nutrition

Feeding ecology: Omnivorous grazer requiring algae, plant material, invertebrate foods and complete prepared foods

Feeding routine: Offer measured varied foods daily and confirm territorial behaviour does not prevent other bottom fish from feeding

Breeding and reproduction

Commercial captive production uses controlled methods; routine home-aquarium spawning is not a realistic expectation.

Breeding plan: Commercial captive production uses controlled methods; routine home-aquarium spawning is not a realistic expectation. Parental care: No routine aquarium parental care.

Compatibility plan

Use robust mid-water tankmates that do not compete for bottom territories; avoid similar shark-like cyprinids and timid bottom dwellers

Filtration and aeration

Filtration: Use mature biological filtration sized for the adult group and feeding load, with protected intakes and a flow pattern suited to the species.

Aeration: Maintain dependable gas exchange and dissolved oxygen with surface agitation or supplementary aeration while preserving sheltered resting areas.

Maintenance

Test water routinely, remove waste and uneaten food, service filtration without destroying biofilm and review stocking as animals mature.

Adult projected load

Adult projected load includes mature body mass, social-group size, territorial space, oxygen demand, feeding waste and breeding output.

Welfare and risk

Maintain the stated adult space and social structure, verify feeding and intervene early when injury, exclusion, weight loss, abnormal respiration or altered behaviour appears. This is not a community algae-cleaner. Juveniles become territorial, and under-sized housing commonly produces relentless chasing.

Main risk: This is not a community algae-cleaner. Juveniles become territorial, and under-sized housing commonly produces relentless chasing.

Biosecurity and release

Never release fish, fry, eggs, aquarium water, sediment, plants or live foods into drains, dams or natural waterways. Confirm current Australian import conditions and South Australian possession, trade and movement rules before acquisition or transfer.

Overridable warnings

Warnings may be overridden only after adult size, group structure, filtration, aeration, compatibility and maintenance capacity are recorded.

Sources