Paracanthocobitis zonalternans

Adult fish usually reach 7–8 cm in length. The body is elongated and the fins are relatively short. Sensitive barbels near the mouth help the fish search for food on the bottom. Females are generally slightly larger than males, whose pectoral fins may have a yellowish or reddish tint. Overall, the fish is grey with a dark pattern that can vary slightly depending on where it comes from.

This species is naturally found in South-East Asia, including eastern India (Manipur state), Burma, western Thailand, and mainland Malaysia. Paracanthocobitis zonalternans occur in diverse biotopes, from small mountain streams to swampy river sections. They usually prefer flowing waters with a pebbly bottom and plenty of wood from fallen branches and tree trunks.

This fish is peaceful toward other species. Minor squabbles may occur between individuals, which is part of their normal social behaviour and never results in injury. They are compatible with many non-aggressive, non-territorial species of comparable size.

A group of 8–10 fish needs a tank of at least 50 litres. The layout can be varied, but provide plenty of hiding places. These may include low broad-leaved plants, various pieces of wood, and crevices and caves made from stones or other decorative elements. Indian almond leaves, oak leaves, or beech leaves can be added to give the water a brownish tint that mimics their natural habitat. Since Paracanthocobitis zonalternans live in flowing waters, pay special attention to water quality. Remove organic waste (leftover food, droppings) regularly, do a 30–50% water change weekly, and maintain the recommended water pH and dGH.

Feed a mix of sinking flakes and granules. However, vary the diet with live or frozen foods such as daphnia, brine shrimp, or bloodworm.

This species is rarely bred commercially, and most specimens in the trade are still wild-caught. However, breeding wild fish is possible. Since the fish eat their own eggs and show no parental care, spawn them in a separate breeding tank. Protect the eggs by covering the bottom with glass marbles or fine mesh so adults cannot reach them. Special decoration in the breeding tank is not essential, but water parameters should match those of the main tank. The minimum equipment is a heater, simple lighting, and a sponge-type air-lift filter. When spawning, place the fullest females with several males in the breeding tank. The males will compete with each other, so you may need to remove all but one and return them to the main tank. After spawning, move the adults out. A single female can lay around 300 eggs. The fry hatch the next day. For the first few hours they feed on the yolk sac, then move to microscopic foods such as infusoria and brine shrimp nauplii.

Non-colourful fish that have remained close to their wild ancestors usually show high hardiness, robust immunity, and resistance to disease. Health problems usually signal unsuitable keeping conditions. Before treating the fish, always check water quality and parameters first. Start treatment only once all readings are back to normal, if treatment is still needed.

Buy with care, as this species often arrives in shops severely starved, which is hard to reverse. A healthy fish should be active, with a full belly rather than a sunken one, and clean skin without visible damage, spots, or fungal signs. Avoid fish that look apathetic, lie on their side constantly, or have an unnaturally thin body. Watch how the fish behave in the tank—they should be curious and explore the bottom. If possible, ask the seller to feed the fish so you can see it eat. Check the fins too: they should be intact, without splits or erosion. Since this is often a wild-caught species, prefer specimens that have already spent time adapting in a shop.