Some freshwater aquarium sharks include the redtail, rainbow and Bala sharks. Redtail sharks require a minimum tank size of 50 gallons and a moderate level of care. They are characterized by jet black bodies and a bright red tail with a white-tipped dorsal fin.
Redtail sharks are farm-raised in Thailand and are semi-aggressive, providing they are the only shark in the tank. As they mature, redtail sharks can become very aggressive toward their own kind. The aquarium habitat should feature hiding spots in the form of dense vegetation, as well as rocks and driftwood. Redtails eat a variety of foods that include freeze-dried bloodworms, flake food and vegetable-based food.
Rainbow sharks are dark grey to black with red fins. They are hardy and may live several years with proper water conditions and good filtration. A 50-gallon tank is the minimum size required to house a rainbow shark. This species is accustomed to swift-moving water in the wild. Some aquarists add a powerhead to the tank to provide a stronger water stream.
Rainbow sharks may set up territories within the aquarium that they defend. Habitats should feature a variety of hiding spots with rocks, wood and vegetation. Rainbow sharks can be fed shrimp pellets, black worms and flaked food.
The Bala shark is a more passive species that is active and visible during the day. Bala sharks have metallic silver bodies with a black and yellow dorsal fin. They require a minimum tank size of 125 gallons. Bala sharks are omnivores and are not picky eaters. They can be fed a variety of food such as tubifex and bloodworms as well as additional plant-based food.