Rainbow Fish

Description

The rainbow shark (*Epalzeorhynchos frenatum*) is a small, freshwater fish native to Southeast Asia, commonly found in Thailand’s rivers and streams. It grows to about 6 inches (15 cm) and has a slender, elongated body with a dark blue-black base color. Its most striking feature is its vibrant red or orange fins, which contrast sharply with its body, earning its “rainbow” name. Juveniles may have less vivid colors that intensify with age.

In aquariums, rainbow sharks are semi-aggressive, often territorial, especially toward similar-looking fish or other rainbow sharks. They prefer a tank with plenty of hiding spots, a sandy or fine gravel substrate, and moderate water flow. They’re omnivorous, eating algae, flake food, and small live or frozen foods. Water conditions should be kept at 75–81°F (24–27°C), pH 6.5–7.5, and hardness 5–15 dGH.

They’re active bottom-dwellers, often seen darting or resting in caves. While hardy and popular in the aquarium trade, they require space (minimum 50-gallon tank for adults) and careful tankmate selection to avoid conflicts. Not a true shark, they belong to the Cyprinidae family, like minnows and carps.