Red-tailed Black Shark

Looks how to spot one

Slender scaled minnow

A velvety jet-black body paired with a bright red to orange tail makes this one of the most recognisable aquarium fish. Grown females are fuller in the body than males.13

Personality what they are like

Spirited and territorial, particularly with its own kind and with similar-looking bottom dwellers. Usually kept as a single fish with robust, faster tankmates that use other parts of the tank.13

Daily activity how busy a day looks

An active swimmer that patrols a home territory near the bottom and is a strong jumper, so the tank needs a lid.13

Grooming and care the hands-on bits

Clean, well-oxygenated water with regular partial changes. Water: about 20-26 C, pH 6.0-8.0 (neutral preferred), hardness up to about 15 dGH.12

Home where they are happiest

A tank with a base of about 120 x 45 cm (around 240 litres), furnished with rocks, driftwood and plants that create caves and break up sight lines.1

Food basics what goes in the bowl

Omnivore that grazes algae and biofilm. Offer quality dried foods, small live or frozen foods such as bloodworm, Daphnia and brine shrimp, and vegetables like blanched courgette and peas.12

Company who they like around

A solitary fish; best kept one per tank.12

The story where it all began

Hugh McCormick Smith described the species in 1931. It was thought to have vanished from the wild in the 1990s until small populations were found again in Thailand in the 2010s. Meanwhile it has stayed a classic aquarium fish, supplied entirely by fish farms.31

Recognised by the official bits

IUCN Red List

Critically Endangered (assessed 2011).2

Aquarium trade

All aquarium fish are captive bred on farms; Thailand exports large numbers every year.2