The Bala shark, Balantiocheilos melanopterus, also known as the tricolor shark, silver shark, or shark minnow, is a fish species of the family Cyprinidae, and has long been considered the sole member of the genus Balantiocheilos. This species is not a true shark, but is commonly called a "shark" because of its torpedo-shaped body and large fins.

Distribution

The Bala shark occurs in the Mekong and Chao Phraya River basins, Malay Peninsula, Sumatra, and Borneo.

Appearance and anatomy

These fish have a silver body with black margins on dorsal, caudal, anal, and pelvic fins. These fish can reach 35 centimetres (14 in).

Habitat and ecology

Bala sharks are found in midwater depths in large and medium-sized rivers and lakes. They feed on phytoplankton, but mostly on small crustaceans, rotifers, and insects and their larvae.

In the aquarium

Bala sharks are popular aquarium fish. Despite the common name "shark", these fish are generally peaceful and good companions to many other types of tropical fish. However, the Bala shark is an omnivore and will eat other animals if they're small enough to fit in their mouths (including other smaller fish, and shrimp). Shrimp (ghost shrimp, krill, etc.) should have adequate hiding places to keep them from getting eaten. Bala sharks are widely available in most pet stores, but these fish may grow to a size too large for the home aquarium.

They're hardy fish that will tolerate temperature changes, pH changes, and other factors to which other fish may be sensitive. The water pH should be 6.0–8.0. The preferable water hardness for this species is soft to medium (5.0–12.0 dGH). Water temperature should be kept between 22–28?C (72–82?F).

Very young Bala sharks are sometimes kept in small aquaria. However, given their adult size, schooling behavior, and swimming speed, the fish quickly grow to need much more room. Hobbyists continue to debate over acceptable minimum tank sizes, but generally recommend at least a 6 feet tank. FishBase lists a minimum of 150 cm (5 ft). Many believe the fish is simply too large and too active to be kept in commercial aquaria at all; only enormous, custom-built tanks are acceptable, if any tank at all is. Indoor ponds are also considered feasible housing options and may be better suited to the average aquarist.

Conservation

B. melanopterus is listed as an endangered species by the IUCN Red List.