Taxonomy & naming
Bleeker described the species in 1850 from Banjarmasin, Borneo; the authority is in parentheses because the species was first described in another genus. Balantiocheilos is a small genus of Southeast Asian minnows, and the bala shark is the one the trade has sold for decades under the name shark minnow.
Morphology
A torpedo-shaped, laterally compressed fish with large eyes, a silver body and a tall forked tail and fins edged in black, as the species name says. The dorsal and anal fins are tall and sail-shaped. FishBase gives a maximum of 14 in SL.
Habitat
FishBase reports adults in mid-water in large and medium-sized rivers and lakes, listed as freshwater and benthopelagic in tropical water of 72–82 °F, pH 6.0 to 8.0 and 5 to 12 dH. The range covers the Mekong and Chao Phraya basins, the Malay Peninsula, Sumatra and Borneo, and the species is described as becoming rare or extinct in many river basins.
Feeding
FishBase says it eats phytoplankton but mostly small crustaceans, rotifers and insects and their larvae.
Mating
Mating behaviour is not described in the sources the atlas uses.
Breeding
Breeding is not described in FishBase.
In the aquarium
FishBase advises keeping it in groups of five or more in an aquarium longer than 59 in. It is an active mid-water swimmer that jumps readily and reaches a size few home tanks can hold. Small fish sold in shops need that space within a couple of years.
Conservation
FishBase lists the species as Vulnerable on the IUCN Red List. FishBase notes it is becoming rare or extinct in many river basins.