Blue Botia

Adults of this species can reach about 25 cm in length. Telling males from females is difficult because sexual dimorphism is weakly expressed, though females are usually somewhat larger. The body is a uniform grey-blue colour, which becomes bright blue under optimal conditions. The fins and tail have an orange tint.

Its natural habitat is in Southeast Asia, spanning present-day Thailand, Laos, Cambodia and Vietnam. The blue botia lives in the middle and lower Mekong River, and in the Chao Phraya and Maekhlong river basins. These fish occur throughout the length of these rivers and in seasonally flooded coastal areas during the rainy season. They prefer sections with moderate flow, where they shelter among rocks and tree roots by day and search for food at dusk.

Compared with other members of the genus, this fish is peaceful and calm. It gets along well with many species of similar or slightly smaller size. Aggressive behaviour may appear only when kept singly, so it is best to buy at least 5 individuals, or preferably 10 and more blue botias. Be aware that they tend to bite the long fins of their tank mates.

For a group of 5 fish, an aquarium of at least 300 litres is recommended. The setup can be flexible, but must meet these conditions: use a soft sandy substrate, provide shelter and dimmed lighting. Live plants are welcome, preferably shade-tolerant, rooted species. Optimal conditions are achieved with weak or moderate internal flow in clean, well-oxygenated water. To maintain these conditions, besides an effective filter, change 30–35% of the water weekly and regularly clean the tank of organic waste.

This fish is a carnivore. In nature its diet includes aquatic insects and larvae, small crustaceans and other zooplankton on the river bed. In the aquarium offer sinking foods such as dry flakes, pellets, and frozen bloodworm, brine shrimp and daphnia. You can also add pieces of earthworm and mollusc meat. Plant matter should be included in the diet, as its absence may lead to the fish damaging fine-leaved plants.

In the wild, spawning peaks during the rainy season from May to July, preceded by migration upriver. After spawning, the fish return downstream. Botias are constantly on the move, travelling hundreds of kilometres through river channels each year. Since they have no parental instinct, eggs are left unguarded after spawning. They drift with the current; some attach to shoreline vegetation, which later provides shelter for the fry. Others die in open water and become prey for other fish. Breeding these fish in home aquariums is extremely rare, whereas on commercial farms offspring are produced by hormonal injection. In the trade, both captive-bred and wild-caught specimens are still available. In some villages, collecting shoreline aquatic vegetation with attached eggs has become a kind of livelihood, and eggs collected this way are sold to fish farms.

Health problems usually arise only from injury or unsuitable conditions, which weakens the immune system and typically triggers various diseases. If signs of illness appear, the first step is to check water parameters for excess or dangerous concentrations of toxins (nitrate, nitrite, ammonia, etc.). Once all values are normal, treatment can begin.

When selecting a blue botia in the shop, choose individuals with clean skin free of visible damage, ulcers, white spots or film. A healthy fish should be active, respond briskly to outside stimuli and actively explore the bottom. Avoid specimens showing apathy, rapid breathing or those that stay alone if the species exhibits schooling behaviour. Do not buy fish with unnaturally bright, 'neon' or spotted colouration atypical for this species. Such individuals are often artificially coloured by dye injection, which severely damages their immune system, shortens lifespan and makes them prone to various diseases. Also examine the fins carefully: they should be intact, free from fraying or torn edges.