The hill streams in which this fish can be found are generally shaded by the forest canopy and dense marginal vegetation. Substrates are typically composed of boulders, smaller stones, sand or gravel with submerged tree roots around the margins and quieter areas in which fallen branches and leaf litter collect.

Other fish species occurring in the Tunga…

Typically inhabits slow-moving, shallow, shady rainforest streams and swamps with dense submerged and marginal vegetation. The conditions are often rather turbid and the substrate composed of mud or fallen leaves, twigs and branches. Such environments characteristically contain soft, weakly acidic water and are often dimly-lit due to the rainforest canopy above. The fish are found sheltering among overhanging tree roots and aquatic vegetation.

The anatomical structure of miniaturised cyprinids can vary greatly, and there are two principle ‘groupings’ with some species possessing intermediate features to some degree. The first contains those fishes which though small are essentially proportionally dwarfed versions of their larger relatives, e.g., Barboides, Microdevario, Microrasbora, Horadandia, Boraras, Sawbwa, Sundadanio, Danio, Laubuca and Rasbora.

The other includes those in which anatom…

The identity of this species was unclear for a number of decades prior to its redescription by Ng and Kottelat (2013).

The confusion originated with Brittan (1954) who misidentified specimens of R. tornieri as R. dusonensis and was exacerbated by Alfred (1963) who concluded that the holotype of R. dusonensis was conspecific with R. myersi.

T. somphongsi is exceptionally rare both in nature and the hobby and was considered potentially extinct for around a dozen years before a trio were imported to Germany as contaminants among a batch of Boraras urophthalmoides in 2006.

Since then it has been successfully bred and distributed to various experts, mostly in Thailand and Germany, in the hope of establishing a sustainable captive population. The possibility of a…

This species was described from ‘Johore River, Segamat, Malaysia’, which corresponds to Segamat District within the the Johor River watershed, Johor state, southern Peninsular Malaysia, but the type specimens were obtained via a Singapore wholesaler so it’s possible that a mistake was made as there exist no other records of the species in Peninsular Malaysia.

It’s also been recorded from the Kapuas drainage…

This species is very scarce in the trade indeed and you're most likely to see it on sale as a contaminant among import of other Indian species.

There are currently 34 described species of Osteochilus although none can be considered popular in the aquarium hobby. According to Rainboth's 'Fishes of the Cambodian Mekong' members of the genus are characterised by lack of aspine, presence of 11-18rays, large rostral and maxillary barbels, papillae on both upper and lower lips,…

This species occurs in several colour forms depending on collection locality with some exhibiting more intense pigmentation in the fins or an additional reddish lateral stripe, for example. It’s sometimes said to closely resemble and occur sympatrically with Rasbora agilis, but that name is currently considered a junior synonym of the congener Trigonopoma pauciperforatum.

R. agilis had previously been us…

All Mystacoleucus species possess a procumbent predorsal spine orientated towards the head, though it can be difficult to spot with the naked eye. This can become entangled in an aquarium net so care must be taken when handling the fish.

The trait is shared by members of Tor, Spinibarbus and Paraspinibarbus although there exists no strong evidence to suggest that these genera form a monophyletic lineage and it is…

This fish is one of several sometimes imported and sold as Oreichthys cosuatis or O. parvus which has led to considerable confusion. It appears to be an undescribed species and can be most easily identified by the absence of a dark marking in the dorsal-fin of adult males (vs. presence in O. cosuatis and O. parvus) and possession of a large, well-defined black blotch on the caudal peduncle ( vs. absent in O. cosuatis, smaller and less well-defined in O. parvus).