Rainbow Snakehead

Adults reach 14–17 cm in length. The body is elongated, characteristic of the genus, and somewhat eel-like; the head is large with a big mouth. From above, the morphology shows a resemblance to snakes. Wild populations display variation in colour. Some specimens are predominantly blue, reddish or brown, with these colours appearing as numerous spots on a darker background or as the main colouration with solid spots of another colour. Snakeheads have evolved a unique accessory breathing organ that allows them to gulp atmospheric air. This enables them to survive for extended periods in waters low in oxygen and to remain viable out of water.

The rainbow snakehead is endemic to the Brahmaputra River basin in the Indian states of Assam and Arunachal Pradesh. In nature it inhabits forest streams, small rivers, swamps and temporary pools that fill during the monsoon season. The habitat is dense with vegetation, fallen leaves and submerged wood, creating numerous refuges. The fish is adapted to seasonal changes, including periods of lower temperature and partial drying of waterbodies, when individuals can survive in the mud.

Young rainbow snakeheads are known for their peaceful nature and can be kept in groups. However, as they mature and reach sexual maturity, they become aggressive toward their own kind. A bonded pair of male and female usually get along well. Because of their modest size, this species can be kept with other peaceful, sufficiently large fish that avoid becoming prey. Tank mates should inhabit the water column or surface; avoid bottom-dwellers such as catfish or loaches.

For one or two fish, the minimum aquarium volume is 100 litres. Tank height is not critical as long as the water depth is at least 30 cm. The rainbow snakehead prefers dimmed lighting, floating plants and various shelters on the bottom. Shelters can be artificial decorations or natural elements such as stone piles or driftwood. A tight-fitting lid is essential, as snakeheads are known to escape by crawling out. This species is undemanding and adapts well to various conditions. The one critical factor is temperature fluctuation, which should mimic natural seasonal changes between winter and summer. In winter, turn off the heater and let the water reach room temperature, around 20°C. In summer, maintain the water at the maximum comfortable level, approximately 27–28°C. The rainbow snakehead is a predator. In nature it feeds on small fish, amphibians, insects, larvae and any other prey it can swallow. In the aquarium, base the diet on fresh pieces of fish, shrimp, mussel, earthworms, large bloodworms and similar foods. Dry foods such as pellets or tablets should be considered only as a supplement, providing vitamins and minerals.

This predator feeds in nature on small fish, amphibians, insects and larvae—anything it can swallow. In the aquarium, base the diet on fresh pieces of fish, shrimp and mussel meat, as well as earthworms and large bloodworms. Dry foods in the form of pellets and tablets should be treated only as a supplement to the main diet, providing the necessary vitamins and minerals. Do not feed mammal or bird meat: the fish cannot digest the lipids they contain, leading to fat deposits and even organ damage.

Reproduction occurs in the aquarium when seasonal temperature changes are simulated. The fish form monogamous pairs; spawning is accompanied by a characteristic courtship dance at the surface. The eggs are buoyant and are gathered by the male into a tight raft-like mass. Both parents actively guard the eggs and subsequent fry. Successful rearing of fry requires the presence of small live food in the tank; the female may also lay unfertilized food eggs for the young to consume.

The species is sensitive to temperature disruption, especially to constant high temperatures, which trigger severe bacterial infections. Symptoms include white spots, ulcers on the body and head, and tissue breakdown, often leading to death. Prevention involves ensuring a seasonal rest period with lower temperature, maintaining high water quality and avoiding live food from dubious sources that may carry parasites.

When selecting fish, choose active individuals with clean fins and no visible damage, ulcers or white coating. Assess body condition and avoid specimens with a sunken belly. Observe behaviour in the shop: healthy fish show curiosity and caution rather than lethargy. Remember that transport is stressful, so minimize time in the bag and use containers with adequate air volume, as snakeheads are obligate air-breathers.