Rainbow shark

The rainbow shark is a freshwater member of the carp family (Cyprinidae), not a true shark, native to the river basins of Southeast Asia. It has a dark grey to black body with strikingly red or orange fins, a downturned mouth suited to grazing, and a slender, streamlined shape. This species is territorial and can be aggressive toward its own kind and other bottom-dwellers, becoming more pugnacious with age. It is best kept singly in a community tank rather than in groups, unless the aquarium is very large. A spacious tank with plenty of caves, driftwood, and hiding places helps diffuse aggression and lets the fish establish a territory. It is an omnivore that grazes on algae, biofilm, and accepts sinking pellets, vegetables, and frozen foods. Suitable tankmates are robust mid- and upper-water fish that stay out of its claimed floor space.