Ambastaia nigrolineata

Adults typically reach 7–8 cm in length. Sexual dimorphism in this species is weakly expressed, making sex determination difficult. The body pattern consists of alternating wide black and light horizontal stripes, with the belly remaining white. In juveniles, the upper light stripe has many vertical crossbars. Near the mouth on the head are sensitive barbels that help the fish find food on the bottom.

The natural habitat of this species is in Southern China, in Yunnan province. The fish inhabits the upper reaches of the Lancang Jiang River basin, also known as the Mekong in China. Wild populations have also been noted in Laos, in the Nan River (a left tributary of the Mekong). Typical biotopes are small streams with sandy bottoms, clear water, and moderate currents.

This peaceful and calm species coexists well with many fish of similar size and temperament that prefer similar conditions. However, avoid keeping Ambastaia nigrolineata with ornamental fish that have long fins, as they may be damaged. It is recommended to keep them in a group of at least 5 individuals, and the best option would be to acquire a school of 10 or more fish.

For a group of 5 fish, the minimum aquarium volume is 80 liters. Soft substrates such as sand or fine gravel are used for decoration. Snags overgrown with ferns and mosses, as well as large boulders, will also be appropriate. With stone arrangements, you can create grottoes and crevices where Ambastaia will gladly hide. Favorable conditions for keeping include subdued lighting, moderate current, and high water quality. A reliable filtration system and weekly water changes of 30–50% of the volume will help avoid excessive accumulation of organic waste.

The diet includes all types of sinking foods, and it is important that they contain vegetable components. An optimal menu may include dry granules or flakes in combination with frozen foods such as bloodworms or brine shrimp, or pieces of earthworms and mollusks. You can also offer pieces of vegetables (e.g., zucchini, spinach, cucumber) secured to the bottom.

In their natural environment, the breeding period for Ambastaia is associated with annual migrations, which cannot be replicated in a home aquarium. In specialized fish farms, fry are obtained through hormonal injections.

Health problems usually arise only as a result of injuries or keeping in unsuitable conditions, which leads to a weakening of the immune system and, as a rule, provokes the development of various diseases. At the first signs of illness, the primary task is to check the water parameters for excesses or dangerous concentrations of toxic substances (nitrates, nitrites, ammonia, etc.). After bringing all indicators back to normal, treatment can begin. More detailed information on symptoms and treatment methods is presented in the "Aquarium Fish Diseases" section.

When selecting individuals, pay attention to their activity and the integrity of their skin. A healthy fish should show curiosity, swim in the water column or actively explore the bottom, rather than constantly hiding in the corners of the aquarium. Avoid specimens with signs of emaciation, sunken bellies, damaged fins, or visible sores on the body.

• ensure there is no white film or spots indicating skin diseases;
• check the integrity of the barbels, as their damage indicates poor keeping conditions or incorrect substrate;
• prefer individuals that show interest in the offered food in the presence of the buyer.