Microdevario

Microdevario microphthalma is a tiny danionid endemic to a single hill-stream system in Yunnan Province, China, the Nanwan River. At a maximum standard length of just 2.6 cm it is one of the smallest vertebrate species in the aquarium trade, and its size alone defines most of its care requirements. The body is semi-translucent with a silvery-green sheen and a dark mid-lateral stripe; the eyes are noticeably small (hence the species name), and the mouth is upward-turned, suggesting a surface-feeding habit. Originally described as Microrasbora microphthalma by Jiang, Chen & Yang in 2008, it was later moved to the genus Microdevario. A 30-litre nano tank is adequate for a small shoal, though a longer footprint is better for these active swimmers. FishBase records a pH of around 6.8 and a tropical temperature minimum of 20°C; the upper bounds are not established in the scientific literature. Provide a densely planted tank with floating cover to diffuse the light. They are peaceful shoalers that must be kept in groups of eight or more. Their tiny mouths require correspondingly small foods: crushed flakes, microworms, freshly hatched Artemia nauplii, and finely powdered dry foods. Rarely seen in chain pet stores; most specimens are wild-caught, so quarantine is essential.