Bala Shark

The bala shark is not a true shark but a large, silver-colored cyprinid. Its pointed dorsal fin, deeply forked tail and the broad black edges on its fins give it a shark-like silhouette. It is sold in stores as 5–8 cm juveniles, but reaches 30–35 cm as an adult.

Its natural populations have declined seriously; the species is listed as "endangered" on the IUCN list. The fish in the trade are largely bred on farms in Southeast Asia.

It lives in schools in the open midwater of large rivers and lakes of the Malay Peninsula, Sumatra and Borneo. The water is clean and rich in oxygen; its level changes seasonally with the monsoon rains.

• Volume: at least 800 liters and 200 cm of length for 4–5 adults; larger if possible. A long, wide swimming area is essential.
• Water: 24–27°C; a wide pH range, powerful filtration and high oxygen.
• Decor: roots and rocks along the edges, a completely open area in the middle.
• Lid: it jumps powerfully when startled; a tight, heavy lid is required. Not switching the light on and off suddenly reduces panic jumps.

Omnivorous. Quality granules and pellets, spirulina and vegetables; frozen brine shrimp, mysis shrimp, bloodworms. It eats small fish and shrimp that fit in its mouth.

Peaceful but skittish and very fast. It feels safe with a group of its own kind; kept alone it swims in constant panic and jumps. Adults see small fish such as neons as prey.

Good companions: peaceful fish of similar size: tinfoil barb, large gouramis, large plecos, clown loach, large rainbowfish species (in a large aquarium).

Avoid: small schooling fish, dwarf shrimp, aggressive large cichlids and fin-nipping species.

Kept in a group of at least 4, ideally 5–6. Group size directly affects behavior: a large group swims more calmly. This in turn increases the volume needed; when buying juveniles, plan for an aquarium that can house the adult group.

It does not breed in the home aquarium. Commercial breeding is done on farms, in large ponds and with hormone support.

Hardy; problems mostly stem from a small aquarium: stunting, jumping injuries, snout abrasions and infections related to poor water. It is susceptible to white spot. Medicating an entire large aquarium is both difficult and expensive; that is why quarantining newly arrived fish in a separate tank for 3–4 weeks is especially important. Because of the high bioload, weekly nitrate testing and regular large water changes are the foundation of good health.

Very difficult to tell apart externally. Mature females have a slightly plumper belly.