This is possibly an undescribed species and has been marketed as ‘Asian Cardinal Rasbora’, ‘flame red rasbora’, M. sp. ‘rose blue line’ or M. ‘thuzari’ in the ornamental trade.

It differs from M. rubescens by its larger adult size, possession of a greenish to bluish lateral stripe, and lesser extent of orange pigmentation on the body. It also appears to represent a distinct genetic lineage (Collins et al., 2012).

Known only from a handful of streams in the upper Mali Hka river drainage, Ayeyarwaddy River system, near Putao township in the far north of Kachin state, northern Myanmar.

Type locality is ‘Nan Hto Chaung in Putao, about 1 mile from 46th regiment, close to rice mill’.

Apparently inhabits calm to moderately-flowing stretches of well-oxygenated headwaters and minor tributaries. Such habitats tend to comprise transparent water, substrates of sand, gravel, rocks, boulders, and patches of leaf litter, with submerged driftwood, roots of riparian vegetation, and aquatic vegetation in places.

Towards the Andaman Sea the lower part of the delta gives way to brackish mangrove swamps. The climate is wet, with annual precipitati0n of 1500 – 2500 mm, up to 90% of which falls between mid May and mid November, and warm with average air temperatures of 22 – 37 °C over the course of the year.

At one locality M. nanus was collected in less then 30cm of water from an oxbow lake among floating Pistia-like vegetation and gra…

The genus Microdevario was raised by Fang et al. (2009) after phylogenetic analyses revealed that some species formerly included in Microrasbora to be more closely allied with Devario and in need of reclassification. Microdevario is largely separated from Devario and other closely related genera such as Chela and Laubuca by virtue of internal characters but also the following: small adult size; anal and dorsal fins with concave-shaped distal margin; absence of barbels; absence of perforated scales; 9-10 branched anal-fin rays; 7 branched dorsal-fin rays; less abdominal than caudal vertebrae.

This species is diagnosable from other members of the genus primarily by its unique colour pattern which consists of 7-11 dark blue, irregularly-shaped, parallel vertical bars on the anterior portion of each flank plus a short horizontal stripe on the caudal peduncle which extends into the central caudal fin rays. Phylogenetic analyses suggest it’s most closely-related to Indian Devario spp. plus D. xyrops from the western slope of the Rakhine Yoma mountains in Myanmar (Fang et al., 2009; Fang and Kullander, 2009).

It can be further distinguished from other species in the genus by colour pattern consisting of a dark, horizontal P stripe originating around mid-body, where it’s relatively faint, this becoming thicker and darker in the posterior portion of the body and terminating at the base of the caudal-fin. Among congeners it’s most similar to D. chrysotaeniatus but that species lacks the infraorbital process, has three rows of pharyngeal teeth and the P stripe extends to the end of the caudal-fin rays.

This species has mostly been collected from small (1-2 metres wide, 20-40 cm deep), moderate-to-swiftly-flowing streams with clear water, substrates of sand, gravel and rocks and no aquatic vegetation. Marginal vegetation was present in some cases, offering a degree of shade, and sympatric species included an unidentified Schistura sp., S. vinciguerrae, Misgurnus anguillicaudatus, Garra qiaojiensis,…

The habitat near Hopong is an area of permanently-flooded grassland formed by the damming of a spring for agricultural purposes and is around 1,040 metres AMSL.

The water is only around 30cm deep, transparent and supports dense growths of aquatic plants, mostly from the family Hydrocharitaceae which includes such genera as Elodea, Egeria and Blyxa.

This species is poorly known and first appeared in the hobby during 2005 but has rarely been seen since, probably because its natural waters lie outside the range of most commercial collectors.

It can be distinguished by a combination of characters including: lateral line complete; infraorbital process absent; two pairs of short barbels; 8-9 branched dorsal fin rays; 12-13 branched anal fin rays; P stripe originating above pelvic fin and extending to en…