Microrasbora rubescens

Adults reach about 3 cm in length. The body is orange with a silvery sheen on the belly. The fins and tail are semi-transparent. Sexual dimorphism is barely visible: males and females are nearly indistinguishable, though females may be slightly larger.

This fish comes from Southeast Asia, specifically Myanmar. Its natural habitat is the small mountain lake Inle and the rivers that flow into it. Microrasbora rubescens is now endangered in the wild. Human activity in the region, intensive collection, and invasive species competing with native fish have all contributed to this decline. Lake Inle is shallow, about 2–3 metres deep, with a silty bottom. The water is clear and clean. Vegetation consists mainly of floating 'green islands'—dense plant mats that shelter many fish species.

These peaceful schooling fish prefer the company of other small, peaceful species. A group of at least 8–10 individuals is recommended, as smaller numbers may make Microrasbora rubescens excessively shy or timid.

For a school of 8–10 fish, a tank of 50 litres or more is recommended. Décor is flexible, but follow a few basic principles: use dark substrate and provide dense plant growth, including floating plants. The tank should recreate Lake Inle conditions—clear water with elevated carbonate hardness. Maintain these by regularly removing waste, changing part of the water weekly, and using efficient filtration, preferably external, to avoid excessive water movement. Adding material to the filter that raises dGH, such as marble chips, is also helpful.

If the fish are tank-bred rather than wild-caught, feeding is straightforward. Most common foods of appropriate size are readily eaten. The ideal diet alternates between dry foods such as flakes and pellets, and live or frozen foods such as brine shrimp and daphnia.

Breeding this species is straightforward and requires no special preparation. Fish spawn readily in the main tank under good conditions. During spawning, females scatter eggs among dense plants, and the fry are left to fend for themselves. Incubation takes 72–96 hours, depending on temperature. Fry swim freely 1–2 days after hatching. Although spontaneous breeding is easy, rearing the fry takes effort. This species, like all Danio, lacks parental care; adults eat their eggs and fry. Fry survival will be extremely poor unless they are moved to a separate tank. A breeding tank of 10–15 litres is usually sufficient. Fill it with water from the main tank. An air-lift filter and heater are needed; separate lighting is not. Feed fry specialized powdered foods. As they grow, gradually introduce larger foods such as brine shrimp nauplii.

In a well-balanced tank suited to this species' needs, disease is rare. Problems usually stem from poor conditions, contact with sick fish, or injury. If a fish shows clear signs of illness, medication is appropriate.

When buying, choose active fish with clean fins and no visible damage or coating on the body. Ensure the fish in the shop are in suitable conditions, as this species is sensitive to water quality and transport stress. Avoid thin, listless fish that stay at the surface; such fish may find it very hard to adapt to a new tank.